Adding upstream version 110.0.1.upstream/110.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

125 files changed, 13281 insertions, 0 deletions

diff --git a/l10n-cy/browser/branding/official/brand.dtd b/l10n-cy/browser/branding/official/brand.dtd
new file mode 100644
index 0000000000..b5474b4c99
--- /dev/null
+++ b/l10n-cy/browser/branding/official/brand.dtd
@@ -0,0 +1,5 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+
+<!ENTITY  brandShortName        "Firefox">
diff --git a/l10n-cy/browser/branding/official/brand.ftl b/l10n-cy/browser/branding/official/brand.ftl
new file mode 100644
index 0000000000..10bb440c63
--- /dev/null
+++ b/l10n-cy/browser/branding/official/brand.ftl
@@ -0,0 +1,39 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+## Firefox Brand
+##
+## Firefox must be treated as a brand, and kept in English.
+## It cannot be:
+## - Declined to adapt to grammatical case.
+## - Transliterated.
+## - Translated.
+##
+## Reference: https://www.mozilla.org/styleguide/communications/translation/
+
+## Firefox and Mozilla Brand
+##
+## Firefox and Mozilla must be treated as a brand.
+##
+## They cannot be:
+## - Transliterated.
+## - Translated.
+##
+## Declension should be avoided where possible, leaving the original
+## brand unaltered in prominent UI positions.
+##
+## For further details, consult:
+## https://mozilla-l10n.github.io/styleguides/mozilla_general/#brands-copyright-and-trademark
+
+-brand-shorter-name = Firefox
+-brand-short-name = Firefox
+-brand-shortcut-name = Firefox
+
+-brand-full-name = Mozilla Firefox
+# This brand name can be used in messages where the product name needs to
+# remain unchanged across different versions (Nightly, Beta, etc.).
+-brand-product-name = Firefox
+-vendor-short-name = Mozilla
+trademarkInfo = Nodau masnachu'r Mozilla Foundation yw Firefox a logos Firefox.
diff --git a/l10n-cy/browser/branding/official/brand.properties b/l10n-cy/browser/branding/official/brand.properties
new file mode 100644
index 0000000000..9d6a612125
--- /dev/null
+++ b/l10n-cy/browser/branding/official/brand.properties
@@ -0,0 +1,8 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+brandShorterName=Firefox
+brandShortName=Firefox
+brandFullName=Mozilla Firefox
+
diff --git a/l10n-cy/browser/browser/aboutCertError.ftl b/l10n-cy/browser/browser/aboutCertError.ftl
new file mode 100644
index 0000000000..4f10b1b8e6
--- /dev/null
+++ b/l10n-cy/browser/browser/aboutCertError.ftl
@@ -0,0 +1,127 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# Variables:
+# $hostname (String) - Hostname of the website with cert error.
+cert-error-intro = Mae { $hostname } yn defnyddio tystysgrif diogelwch annilys.
+
+cert-error-mitm-intro = Mae gwefannau'n profi eu hunaniaeth drwy dystysgrifau, sy'n cael eu cyhoeddi gan awdurdodau tystysgrifau.
+
+cert-error-mitm-mozilla = Mae { -brand-short-name } yn cael ei gefnogi gan Mozilla y corff dim-er-elw, sy'n gweinyddu storfa awdurdod tystysgrifau (CA) cwbl agored. Mae'r storfa'n cynorthwyo i sicrhau fod awdurdodau tystysgrif yn dilyn ymarfer gorau ar gyfer diogelwch defnyddwyr.
+
+cert-error-mitm-connection = Mae { -brand-short-name } yn defnyddio storfa CA Mozilla i wirio bod cysylltiad yn ddiogel, yn hytrach na thystysgrifau wedi eu cyflenwi gan system weithredu'r defnyddiwr. Felly, os yw rhaglen gwrth-firws neu rwydwaith yn rhyng-gipio cysylltiad â thystysgrif diogelwch a gyhoeddwyd gan CA nad yw yn storfa CA Mozilla, mae'n ystyried bod y cysylltiad yn anniogel.
+
+cert-error-trust-unknown-issuer-intro = Gall fod rhywun yn ceisio efelychu'r wefan a pheidiwch â mynd yn eich blaen.
+
+# Variables:
+# $hostname (String) - Hostname of the website with cert error.
+cert-error-trust-unknown-issuer = Mae gwefannau'n profi eu hunaniaeth drwy dystysgrifau. Nid yw { -brand-short-name } yn ymddiried yn { $hostname } gan nad yw ei gyhoeddwr tystysgrifau'n hysbys, mae'r dystysgrif wedi ei llofnodi ganddo'i hun neu nid yw'r gweinydd yn anfon y tystysgrifau rhyngol cywir.
+
+cert-error-trust-cert-invalid = Nid oes modd ymddiried yn y dystysgrif am ei fod wedi rhyddhau tystysgrif CA annilys.
+
+cert-error-trust-untrusted-issuer = Nid oes modd ymddiried yn y dystysgrif oherwydd nad oes modd ymddiried yn ei chyhoeddwr.
+
+cert-error-trust-signature-algorithm-disabled = Nid oes ymddiriedaeth i'r dystysgrif gan ei fod wedi ei lofnodi gan ddefnyddio algorithm llofnod sydd wedi ei analluogi am nad yw'r algorithm yn anniogel.
+
+cert-error-trust-expired-issuer = Nid oes modd ymddiried yn y dystysgrif oherwydd bod y dystysgrif ryddhau wedi dod i ben.
+
+cert-error-trust-self-signed = Nid oes modd ymddiried yn y dystysgrif am ei fod wedi ei hunanlofnodi.
+
+cert-error-trust-symantec = Nid yw tystysgrifau a gyhoeddwyd gan GeoTrust, RapidSSL, Symantec, Thawte, a VeriSign bellach yn cael eu hystyried yn ddiogel oherwydd nad oedd yr awdurdodau tystysgrif hyn yn dilyn arferion diogelwch yn y gorffennol.
+
+cert-error-untrusted-default = Nid yw'r dystysgrif yn dod o fan gellir ymddiried ynddo.
+
+# Variables:
+# $hostname (String) - Hostname of the website with cert error.
+cert-error-domain-mismatch = Mae gwefannau'n profi eu hunaniaeth drwy dystysgrifau. Nid yw { -brand-short-name } yn ymddiried yn y wefan hon gan ei fod yn defnyddio tystysgrif nad yw'n ddilys ar gyfer { $hostname }.
+
+# Variables:
+# $hostname (String) - Hostname of the website with cert error.
+# $alt-name (String) - Alternate domain name for which the cert is valid.
+cert-error-domain-mismatch-single = Mae gwefannau'n profi eu hunaniaeth drwy dystysgrifau. Nid yw { -brand-short-name } yn ymddiried yn y wefan hon gan ei fod yn defnyddio tystysgrif nad yw'n ddilys ar gyfer { $hostname }. Dim ond ar gyfer <a data-l10n-name="domain-mismatch-link">{ $alt-name }</a> mae'r dystysgrif yn ddilys.
+
+# Variables:
+# $hostname (String) - Hostname of the website with cert error.
+# $alt-name (String) - Alternate domain name for which the cert is valid.
+cert-error-domain-mismatch-single-nolink = Mae gwefannau'n profi eu hunaniaeth drwy dystysgrifau. Nid yw { -brand-short-name } yn ymddiried yn y wefan hon gan ei fod yn defnyddio tystysgrif nad yw'n ddilys ar gyfer { $hostname }. Dim ond ar gyfer { $alt-name } mae'r dystysgrif yn ddilys.
+
+# Variables:
+# $subject-alt-names (String) - Alternate domain names for which the cert is valid.
+cert-error-domain-mismatch-multiple = Mae gwefannau yn profi eu hunaniaeth trwy dystysgrifau. Nid yw { -brand-short-name } yn ymddiried yn y wefan hon oherwydd ei fod yn defnyddio tystysgrif nad yw'n ddilys ar gyfer { $hostname }. Mae'r dystysgrif yn ddilys yn unig ar gyfer yr enwau canlynol: { $subject-alt-names }
+
+# Variables:
+# $hostname (String) - Hostname of the website with cert error.
+# $not-after-local-time (Date) - Certificate is not valid after this time.
+cert-error-expired-now = Mae gwefannau yn profi eu hunaniaeth trwy dystysgrifau, sy'n ddilys am gyfnod penodol. Daeth y dystysgrif ar gyfer { $hostname } i ben ar { $not-after-local-time }.
+
+# Variables:
+# $hostname (String) - Hostname of the website with cert error.
+# $not-before-local-time (Date) - Certificate is not valid before this time.
+cert-error-not-yet-valid-now = Mae gwefannau yn profi eu hunaniaeth trwy dystysgrifau, sy'n ddilys am gyfnod penodol. Ni fydd y dystysgrif ar gyfer { $hostname } yn ddilys tan { $not-before-local-time }.
+
+# Variables:
+# $error (String) - NSS error code string that specifies type of cert error. e.g. unknown issuer, invalid cert, etc.
+cert-error-code-prefix-link = Cod gwall: <a data-l10n-name="error-code-link">{ $error }</a>
+
+# Variables:
+# $hostname (String) - Hostname of the website with cert error.
+cert-error-symantec-distrust-description = Mae gwefannau yn profi eu hunaniaeth trwy dystysgrifau, sy'n cael eu cyhoeddir gan awdurdodau tystysgrif. Nid yw'r mwyafrif o borwyr bellach yn ymddiried mewn tystysgrifau a gyhoeddir gan GeoTrust, RapidSSL, Symantec, Thawte, a VeriSign. Mae { $hostname } yn defnyddio tystysgrif gan un o'r awdurdodau hyn ac felly nid oes modd profi hunaniaeth y wefan.
+
+cert-error-symantec-distrust-admin = Gallwch hysbysu gweinyddwr y wefan am y broblem hon.
+
+cert-error-old-tls-version = Mae'n bosibl na fydd y wefan hon yn cefnogi'r protocol TLS 1.2, sef y fersiwn lleiaf a gefnogir gan { -brand-short-name }.
+
+# Variables:
+# $hasHSTS (Boolean) - Indicates whether HSTS header is present.
+cert-error-details-hsts-label = Diogelwch Trosglwyddo Llym HTTP: { $hasHSTS }
+
+# Variables:
+# $hasHPKP (Boolean) - Indicates whether HPKP header is present.
+cert-error-details-key-pinning-label = Pinio Allwedd Cyhoeddus HTTP: { $hasHPKP }
+
+cert-error-details-cert-chain-label = Cadwyn tystysgrif:
+
+open-in-new-window-for-csp-or-xfo-error = Agor Gwefan mewn Ffenestr Newydd
+
+# Variables:
+# $hostname (String) - Hostname of the website blocked by csp or xfo error.
+csp-xfo-blocked-long-desc = Er mwyn amddiffyn eich diogelwch, ni fydd { $hostname } yn caniatáu i { -brand-short-name } ddangos y dudalen os yw gwefan arall wedi'i mewnblannu ynddi. I weld y dudalen hon, bydd angen i chi ei hagor mewn ffenestr newydd.
+
+## Messages used for certificate error titles
+
+connectionFailure-title = Methu cysylltu
+deniedPortAccess-title = Mae'r cyfeiriad wedi ei gyfyngu
+# "Hmm" is a sound made when considering or puzzling over something.
+# You don't have to include it in your translation if your language does not have a written word like this.
+dnsNotFound-title = Hmm. Rydym yn cael trafferth canfod y wefan honno.
+fileNotFound-title = Heb ganfod ffeil
+fileAccessDenied-title = Mae mynediad at y ffeil wedi ei wrthod
+generic-title = Wps.
+captivePortal-title = Mewngofnodi i'r rhwydwaith
+# "Hmm" is a sound made when considering or puzzling over something.
+# You don't have to include it in your translation if your language does not have a written word like this.
+malformedURI-title = Hmm. Dyw'r cyfeiriad yna ddim yn edrych yn iawn.
+netInterrupt-title = Cafodd y cysylltiad ei darfu
+notCached-title = Daeth y Ddogfen i Ben
+netOffline-title = Modd all-lein
+contentEncodingError-title = Gwall Amgodio Cynnwys
+unsafeContentType-title = Math Anniogel o ffeil
+netReset-title = Cafodd y cysylltiad ei ailosod
+netTimeout-title = Mae cyfnod y cyswllt wedi dod i ben
+unknownProtocolFound-title = Heb ddeall y cyfeiriad
+proxyConnectFailure-title = Mae'r gweinydd dirprwy yn gwrthod cysylltiadau
+proxyResolveFailure-title = Methu canfod y gweinydd dirprwyol
+redirectLoop-title = Nid yw'r dudalen yn ailgyfeirio'n iawn
+unknownSocketType-title = Ymateb annisgwyl gan y gweinydd
+nssFailure2-title = Methodd y Cysylltiad Diogel
+csp-xfo-error-title = Nid yw { -brand-short-name } yn Gallu Agor y Dudalen hon
+corruptedContentError-title = Gwall Cynnwys Llygredig
+sslv3Used-title = Methu Cysylltu'n Ddiogel
+inadequateSecurityError-title = Nid yw eich cysylltiad yn ddiogel
+blockedByPolicy-title = Tudalen wedi'i Rhwystro
+clockSkewError-title = Mae cloc eich cyfrifiadur yn anghywir
+networkProtocolError-title = Gwall Protocol Rhwydwaith
+nssBadCert-title = Rhybudd: Risg Diogelwch Posibl o'ch Blaen
+nssBadCert-sts-title = Peidiwch Cysylltu: Mater Diogelwch Posib
+certerror-mitm-title = Mae Meddalwedd yn Rhwystro { -brand-short-name } Rhag Cysylltu'n Ddiogel i'r Wefan Hon
diff --git a/l10n-cy/browser/browser/aboutDialog.ftl b/l10n-cy/browser/browser/aboutDialog.ftl
new file mode 100644
index 0000000000..96db16e9c9
--- /dev/null
+++ b/l10n-cy/browser/browser/aboutDialog.ftl
@@ -0,0 +1,48 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+aboutDialog-title =
+    .title = Ynghylch { -brand-full-name }
+releaseNotes-link = Beth sy'n newydd
+update-checkForUpdatesButton =
+    .label = Gwirio am ddiweddariadau
+    .accesskey = G
+update-updateButton =
+    .label = Ailgychwyn i ddiweddaru { -brand-shorter-name }
+    .accesskey = A
+update-checkingForUpdates = Wrthi'n gwirio am ddiweddariadau…
+update-downloading = <img data-l10n-name="icon"/>Wrthi'n llwytho'r diweddariad i lawr — <label data-l10n-name="download-status"/>
+update-downloading-message = Wrthi'n llwytho'r diweddariad i lawr — <label data-l10n-name="download-status"/>
+update-applying = Wrthi'n gosod y diweddariad…
+update-failed = Methodd y diweddaru. <label data-l10n-name="failed-link">Llwythwch y fersiwn diweddaraf i lawr</label>
+update-failed-main = Methodd y diweddaru. <a data-l10n-name="failed-link-main">Llwythwch y fersiwn diweddaraf i lawr</a>
+update-adminDisabled = Mae'r diweddariad wedi ei analluogi gan eich gweinyddwr
+update-noUpdatesFound = Mae { -brand-short-name } yn gyfredol
+aboutdialog-update-checking-failed = Wedi methu â gwirio am ddiweddariadau.
+update-otherInstanceHandlingUpdates = Mae { -brand-short-name } yn cael ei ddiweddaru gan enghraifft arall
+update-manual = Mae diweddariadau ar gael yn <label data-l10n-name="manual-link"/>
+update-unsupported = Nid oes modd i chi ddiweddaru'r system hon ymhellach. <label data-l10n-name="unsupported-link">Dysgu rhagor</label>
+update-restarting = Ailgychwyn…
+update-internal-error = Methu gwirio am ddiweddariadau oherwydd gwall mewnol. Mae diweddariadau ar gael yn <label data-l10n-name="manual-link"/>
+channel-description = Rydych ar sianel diweddaru <label data-l10n-name="current-channel"></label>.
+warningDesc-version = Mae { -brand-short-name } yn arbrofol a gall fod yn ansad.
+aboutdialog-help-user = Cymorth { -brand-product-name }
+aboutdialog-submit-feedback = Cyflwyno Adborth
+community-exp = <label data-l10n-name="community-exp-mozillaLink">Mae { -vendor-short-name }</label> yn <label data-l10n-name="community-exp-creditsLink">gymuned fyd-eang</label> sy'n cydweithio i gadw'r We yn agored, cyhoeddus ac ar gael i bawb.
+community-2 = Cynlluniwyd { -brand-short-name } gan <label data-l10n-name="community-mozillaLink">{ -vendor-short-name }</label>, <label data-l10n-name="community-creditsLink">cymuned fyd-eang</label> sy'n cydweithio i gadw'r We yn agored, cyhoeddus ac ar gael i bawb.
+helpus = Eisiau helpu? <label data-l10n-name="helpus-donateLink">Gallwch wneud rhodd</label> neu <label data-l10n-name="helpus-getInvolvedLink">ymuno â ni!</label>
+bottomLinks-license = Manylion Trwyddedu
+bottomLinks-rights = Hawliau'r Defnyddiwr
+bottomLinks-privacy = Polisi Preifatrwydd
+# Example of resulting string: 66.0.1 (64-bit)
+# Variables:
+#   $version (String): version of Firefox, e.g. 66.0.1
+#   $bits (Number): bits of the architecture (32 or 64)
+aboutDialog-version = { $version } ({ $bits }-did)
+# Example of resulting string: 66.0a1 (2019-01-16) (64-bit)
+# Variables:
+#   $version (String): version of Firefox for Nightly builds, e.g. 66.0a1
+#   $isodate (String): date in ISO format, e.g. 2019-01-16
+#   $bits (Number): bits of the architecture (32 or 64)
+aboutDialog-version-nightly = { $version } ({ $isodate }) ({ $bits }-did)
diff --git a/l10n-cy/browser/browser/aboutLogins.ftl b/l10n-cy/browser/browser/aboutLogins.ftl
new file mode 100644
index 0000000000..fa98a60afd
--- /dev/null
+++ b/l10n-cy/browser/browser/aboutLogins.ftl
@@ -0,0 +1,410 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+# NOTE: New strings should use the about-logins- prefix.
+
+about-logins-page-title = Mewngofnodion a Chyfrineiriau
+login-filter =
+    .placeholder = Chwilio Mewngofnodion
+create-login-button = Creu Mewngofnod Newydd
+create-new-login-button =
+    .title = Creu mewngofnod newydd
+fxaccounts-sign-in-text = Defnyddiwch eich cyfrineiriau ar eich dyfeisiau eraill
+fxaccounts-sign-in-sync-button = Mewngofnodi i gydweddu
+fxaccounts-avatar-button =
+    .title = Rheoli cyfrif
+
+## The ⋯ menu that is in the top corner of the page
+
+menu =
+    .title = Agor dewislen
+# This menuitem is only visible on Windows and macOS
+about-logins-menu-menuitem-import-from-another-browser = Mewnforio o Borwr Arall…
+about-logins-menu-menuitem-import-from-a-file = Mewnforio o Ffeil…
+about-logins-menu-menuitem-export-logins = Allforio Mewngofnodion…
+about-logins-menu-menuitem-remove-all-logins = Tynnu Pob Mewngofnod…
+menu-menuitem-preferences =
+    { PLATFORM() ->
+        [windows] Opsiynau
+       *[other] Dewisiadau
+    }
+about-logins-menu-menuitem-help = Cymorth
+
+## Login List
+
+login-list =
+    .aria-label = Mewngofnodi yn cyfateb i ymholiad chwilio
+login-list-count =
+    { $count ->
+        [zero] { $count } mewngofnod
+        [one] { $count } mewngofnod
+        [two] { $count } mewngofnod
+        [few] { $count } mewngofnod
+        [many] { $count } mewngofnod
+       *[other] { $count } mewngofnod
+    }
+login-list-sort-label-text = Trefnu yn ôl
+login-list-name-option = Enw (A-Z)
+login-list-name-reverse-option = Enw (Z-A)
+login-list-username-option = Enw defnyddiwr (A-Z)
+login-list-username-reverse-option = Enw defnyddiwr (Z-A)
+about-logins-login-list-alerts-option = Rhybuddion
+login-list-last-changed-option = Newidiwyd Diwethaf
+login-list-last-used-option = Defnyddiwyd Diwethaf
+login-list-intro-title = Heb ganfod mewngofnodion
+login-list-intro-description = Pan fyddwch yn cadw cyfrinair yn { -brand-product-name }, bydd yn ymddangos yma.
+about-logins-login-list-empty-search-title = Heb ganfod mewngofnodion
+about-logins-login-list-empty-search-description = Nid oes unrhyw ganlyniadau sy'n cyfateb i'ch chwiliad.
+login-list-item-title-new-login = Mewngofnod Newydd
+login-list-item-subtitle-new-login = Rhowch eich manylion mewngofnodi
+login-list-item-subtitle-missing-username = (dim enw defnyddwyr)
+about-logins-list-item-breach-icon =
+    .title = Gwefan wedi dioddef tor-data
+about-logins-list-item-vulnerable-password-icon =
+    .title = Cyfrinair bregus
+about-logins-list-section-breach = Gwefannau wedi dioddef tor-data
+about-logins-list-section-vulnerable = Cyfrinair bregus
+about-logins-list-section-nothing = Dim rhybudd
+about-logins-list-section-today = Heddiw
+about-logins-list-section-yesterday = Ddoe
+about-logins-list-section-week = Y 7 diwrnod diwethaf
+
+## Introduction screen
+
+about-logins-login-intro-heading-logged-out2 = Yn chwilio am eich mewngofnodi wedi'u cadw? Trowch cydweddu ymlaen neu eu mewnforio.
+about-logins-login-intro-heading-logged-in = Heb ganfod mewngofnodion wedi'u cydweddu.
+login-intro-description = Os gwnaethoch gadw eich mewngofnodion i { -brand-product-name } ar ddyfais wahanol, dyma sut i'w cael yma:
+login-intro-instructions-fxa = Crëwch neu fewngofnodwch i'ch cyfrif { -fxaccount-brand-name } ar y ddyfais lle mae'ch mewngofnodion yn cael eu cadw
+login-intro-instructions-fxa-settings = Ewch i Gosodiadau > Sync > Cychwyn cydweddu... Dewiswch y blwch ticio Mewngofnodi a chyfrineiriau.
+login-intro-instructions-fxa-passwords-help = Ewch i <a data-l10n-name="passwords-help-link">cefnogaeth cyfrineiriau</a> i gael rhagor o gymorth.
+about-logins-intro-browser-only-import = Os yw eich mewngofnodion yn cael eu cadw mewn porwr arall, gallwch <a data-l10n-name="import-link">eu mewnforio i { -brand-product-name }</a>
+about-logins-intro-import2 = Os yw eich mewngofnodion wedi'u cadw y tu allan i { -brand-product-name }, gallwch <a data-l10n-name="import-browser-link">eu mewnforio o borwr arall</a> neu <a data-l10n-name="import-file-link">o ffeil</a>
+
+## Login
+
+login-item-new-login-title = Creu Mewngofnod Newydd
+login-item-edit-button = Golygu
+about-logins-login-item-remove-button = Tynnu
+login-item-origin-label = Cyfeiriad Gwefan
+login-item-tooltip-message = Gwnewch yn siŵr fod hyn yn cyfateb i union gyfeiriad y wefan lle rydych yn mewngofnodi.
+login-item-origin =
+    .placeholder = https://www.example.com
+login-item-username-label = Enw Defnyddiwr
+about-logins-login-item-username =
+    .placeholder = (dim enw defnyddwyr)
+login-item-copy-username-button-text = Copïo
+login-item-copied-username-button-text = Copïwyd
+login-item-password-label = Cyfrinair
+login-item-password-reveal-checkbox =
+    .aria-label = Dangos cyfrinair
+login-item-copy-password-button-text = Copïo
+login-item-copied-password-button-text = Copïwyd
+login-item-save-changes-button = Cadw Newidiadau
+login-item-save-new-button = Cadw
+login-item-cancel-button = Diddymu
+login-item-time-changed = Newidiwyd ddiwethaf: { DATETIME($timeChanged, day: "numeric", month: "long", year: "numeric") }
+login-item-time-created = Crëwyd: { DATETIME($timeCreated, day: "numeric", month: "long", year: "numeric") }
+login-item-time-used = Defnyddiwyd ddiwethaf: { DATETIME($timeUsed, day: "numeric", month: "long", year: "numeric") }
+
+## The date is displayed in a timeline showing the password evolution.
+## A label is displayed under the date to describe the type of change.
+## (e.g. updated, created, etc.)
+
+login-item-timeline-point-date = { DATETIME($datetime, day: "numeric", month: "short", year: "numeric") }
+login-item-timeline-action-created = Crëwyd
+login-item-timeline-action-updated = Diweddarwyd
+login-item-timeline-action-used = Defnyddiwyd
+
+## OS Authentication dialog
+
+about-logins-os-auth-dialog-caption = { -brand-full-name }
+
+## The macOS strings are preceded by the operating system with "Firefox is trying to "
+## and includes subtitle of "Enter password for the user "xxx" to allow this." These
+## notes are only valid for English. Please test in your respected locale.
+
+# This message can be seen when attempting to edit a login in about:logins on Windows.
+about-logins-edit-login-os-auth-dialog-message-win = I olygu eich mewngofnod, rhowch eich manylion mewngofnodi Windows. Mae hyn yn helpu i amddiffyn diogelwch eich cyfrifon.
+# This message can be seen when attempting to edit a login in about:logins
+# On MacOS, only provide the reason that account verification is needed. Do not put a complete sentence here.
+about-logins-edit-login-os-auth-dialog-message-macosx = golygu'r mewngofnod sydd wedi'i gadw
+# This message can be seen when attempting to reveal a password in about:logins on Windows.
+about-logins-reveal-password-os-auth-dialog-message-win = I weld eich cyfrinair, rhowch eich manylion mewngofnodi Windows. Mae hyn yn helpu i amddiffyn diogelwch eich cyfrifon.
+# This message can be seen when attempting to reveal a password in about:logins
+# On MacOS, only provide the reason that account verification is needed. Do not put a complete sentence here.
+about-logins-reveal-password-os-auth-dialog-message-macosx = dadlennu'r cyfrinair sydd wedi'i gadw
+# This message can be seen when attempting to copy a password in about:logins on Windows.
+about-logins-copy-password-os-auth-dialog-message-win = I gopïo'ch cyfrinair, rhowch eich manylion mewngofnodi Windows. Mae hyn yn helpu i amddiffyn diogelwch eich cyfrifon.
+# This message can be seen when attempting to copy a password in about:logins
+# On MacOS, only provide the reason that account verification is needed. Do not put a complete sentence here.
+about-logins-copy-password-os-auth-dialog-message-macosx = copïo'r cyfrinair sydd wedi'i gadw
+# This message can be seen when attempting to export a password in about:logins on Windows.
+about-logins-export-password-os-auth-dialog-message-win = I allforio'ch mewngofnodion, nodwch eich manylion mewngofnodi Windows. Mae hyn yn helpu i amddiffyn diogelwch eich cyfrifon.
+# This message can be seen when attempting to export a password in about:logins
+# On MacOS, only provide the reason that account verification is needed. Do not put a complete sentence here.
+about-logins-export-password-os-auth-dialog-message-macosx = allforio mewngofnodion a chyfrineiriau wedi'u cadw
+
+## Primary Password notification
+
+about-logins-primary-password-notification-message = Rhowch eich Prif Gyfrinair i weld mewngofnodi a chyfrineiriau wedi'u cadw
+master-password-reload-button =
+    .label = Mewngofnodi
+    .accesskey = M
+
+## Dialogs
+
+confirmation-dialog-cancel-button = Diddymu
+confirmation-dialog-dismiss-button =
+    .title = Diddymu
+about-logins-confirm-remove-dialog-title = Tynnu'r mewngofnod?
+confirm-delete-dialog-message = Nid oes modd dadwneud y weithred hon.
+about-logins-confirm-remove-dialog-confirm-button = Tynnu
+about-logins-confirm-remove-all-dialog-confirm-button-label =
+    { $count ->
+        [1] Tynnu
+        [zero] Tynnu
+        [one] Tynnu
+        [two] Tynnu
+        [few] Tynnu
+        [many] Tynnu
+       *[other] Tynnu'r Cyfan
+    }
+about-logins-confirm-remove-all-dialog-checkbox-label =
+    { $count ->
+        [1] Ie, tynnu'r mewngofnod
+        [zero] Ie, tynnu'r mewngofnodion
+        [one] Ie, tynnu'r mewngofnod
+        [two] Ie, tynnu'r mewngofnodion
+        [few] Ie, tynnu'r mewngofnodion
+        [many] Ie, tynnu'r mewngofnodion
+       *[other] Ie, tynnu'r mewngofnodion
+    }
+about-logins-confirm-remove-all-dialog-title =
+    { $count ->
+        [zero] Tynnu { $count } mewngofnodion
+        [one] Tynnu { $count } mewngofnod
+        [two] Tynnu { $count } fewngofnod
+        [few] Tynnu { $count } mewngofnod
+        [many] Tynnu { $count } mewngofnod
+       *[other] Tynnu { $count } mewngofnod
+    }
+about-logins-confirm-remove-all-dialog-message =
+    { $count ->
+        [1] Bydd hyn yn dileu'r mewngofnod rydych wedi'i gadw i { -brand-short-name } ac unrhyw rybuddion tor-data sy'n ymddangos yma. Nid oes modd i chi ddadwneud y weithred hon.
+        [zero] Bydd hyn yn dileu'r mewngofnodion rydych wedi'u cadw i { -brand-short-name } ac unrhyw rybuddion tor-data sy'n ymddangos yma. Nid oes modd i chi ddadwneud y weithred hon.
+        [one] Bydd hyn yn dileu'r mewngofnod rydych wedi'i gadw i { -brand-short-name } ac unrhyw rybuddion tor-data sy'n ymddangos yma. Nid oes modd i chi ddadwneud y weithred hon.
+        [two] Bydd hyn yn dileu'r mewngofnodion rydych wedi'u cadw i { -brand-short-name } ac unrhyw rybuddion tor-data sy'n ymddangos yma. Nid oes modd i chi ddadwneud y weithred hon.
+        [few] Bydd hyn yn dileu'r mewngofnodion rydych wedi'u cadw i { -brand-short-name } ac unrhyw rybuddion tor-data sy'n ymddangos yma. Nid oes modd i chi ddadwneud y weithred hon.
+        [many] Bydd hyn yn dileu'r mewngofnodion rydych wedi'u cadw i { -brand-short-name } ac unrhyw rybuddion tor-data sy'n ymddangos yma. Nid oes modd i chi ddadwneud y weithred hon.
+       *[other] Bydd hyn yn dileu'r mewngofnodion rydych wedi'u cadw i { -brand-short-name } ac unrhyw rybuddion tor-data sy'n ymddangos yma. Nid oes modd i chi ddadwneud y weithred hon.
+    }
+about-logins-confirm-remove-all-sync-dialog-title =
+    { $count ->
+        [zero] Tynnu'r { $count } mewngofnodion o'r holl ddyfeisiau?
+        [one] Tynnu'r { $count } mewngofnod o'r holl ddyfeisiau?
+        [two] Tynnu'r { $count } fewngofnod o'r holl ddyfeisiau?
+        [few] Tynnu'r { $count } mewngofnod o'r holl ddyfeisiau?
+        [many] Tynnu'r { $count } mewngofnod o'r holl ddyfeisiau?
+       *[other] Tynnu'r { $count } mewngofnod o'r holl ddyfeisiau?
+    }
+about-logins-confirm-remove-all-sync-dialog-message =
+    { $count ->
+        [1] Bydd hyn yn tynnu'r mewngofnod rydych wedi'i gadw i { -brand-short-name } ar bob dyfais sy'n cael ei gydweddu i'ch { -fxaccount-brand-name }. Bydd hyn hefyd yn dileu rhybuddion tor-data sy'n ymddangos yma. Nid oes modd i chi ddadwneud y weithred hon.
+        [zero] Bydd hyn yn tynnu'r holl fewngofnodion rydych wedi'u cadw i { -brand-short-name } ar bob dyfais sy'n cael ei gydweddu i'ch { -fxaccount-brand-name }. Bydd hyn hefyd yn dileu rhybuddion tor-data sy'n ymddangos yma. Nid oes modd i chi ddadwneud y weithred hon.
+        [one] Bydd hyn yn tynnu'r mewngofnod rydych wedi'i gadw i { -brand-short-name } ar bob dyfais sy'n cael ei gydweddu i'ch { -fxaccount-brand-name }. Bydd hyn hefyd yn dileu rhybuddion tor-data sy'n ymddangos yma. Nid oes modd i chi ddadwneud y weithred hon.
+        [two] Bydd hyn yn tynnu'r holl fewngofnodion rydych wedi'u cadw i { -brand-short-name } ar bob dyfais sy'n cael ei gydweddu i'ch { -fxaccount-brand-name }. Bydd hyn hefyd yn dileu rhybuddion tor-data sy'n ymddangos yma. Nid oes modd i chi ddadwneud y weithred hon.
+        [few] Bydd hyn yn tynnu'r holl fewngofnodion rydych wedi'u cadw i { -brand-short-name } ar bob dyfais sy'n cael ei gydweddu i'ch { -fxaccount-brand-name }. Bydd hyn hefyd yn dileu rhybuddion tor-data sy'n ymddangos yma. Nid oes modd i chi ddadwneud y weithred hon.
+        [many] Bydd hyn yn tynnu'r holl fewngofnodion rydych wedi'u cadw i { -brand-short-name } ar bob dyfais sy'n cael ei gydweddu i'ch { -fxaccount-brand-name }. Bydd hyn hefyd yn dileu rhybuddion tor-data sy'n ymddangos yma. Nid oes modd i chi ddadwneud y weithred hon.
+       *[other] Bydd hyn yn tynnu'r holl fewngofnodion rydych wedi'u cadw i { -brand-short-name } ar bob dyfais sy'n cael ei gydweddu i'ch { -fxaccount-brand-name }. Bydd hyn hefyd yn dileu rhybuddion tor-data sy'n ymddangos yma. Nid oes modd i chi ddadwneud y weithred hon.
+    }
+about-logins-confirm-export-dialog-title = Allforio mewngofnodion a chyfrineiriau
+about-logins-confirm-export-dialog-message = Bydd eich cyfrineiriau'n cael eu cadw fel testun darllenadwy (e.e. BadP@ssw0rd) fel y gall unrhyw un sy'n gallu agor y ffeil a allforiwyd eu gweld.
+about-logins-confirm-export-dialog-confirm-button = Allforio…
+about-logins-alert-import-title = Wedi Cwblhau Mewnforio
+about-logins-alert-import-message = Gweld crynodeb mewnforio manwl
+confirm-discard-changes-dialog-title = Hepgor newidiadau heb eu cadw?
+confirm-discard-changes-dialog-message = Bydd yr holl newidiadau sydd heb eu cadw'n cael eu colli.
+confirm-discard-changes-dialog-confirm-button = Dileu
+
+## Breach Alert notification
+
+about-logins-breach-alert-title = Tor-data Gwefan
+breach-alert-text = Cafodd cyfrineiriau eu ryddhau neu eu dwyn o'r wefan hon ers i chi ddiweddaru'ch manylion mewngofnodi ddiwethaf. Newid eich cyfrinair i ddiogelu eich cyfrif.
+about-logins-breach-alert-date = Digwyddodd y tor-data hwn ar { DATETIME($date, day: "numeric", month: "long", year: "numeric") }
+# Variables:
+#   $hostname (String) - The hostname of the website associated with the login, e.g. "example.com"
+about-logins-breach-alert-link = Mynd i { $hostname }
+about-logins-breach-alert-learn-more-link = Dysgu rhagor
+
+## Vulnerable Password notification
+
+about-logins-vulnerable-alert-title = Cyfrinair Bregus
+about-logins-vulnerable-alert-text2 = Defnyddiwyd y cyfrinair hwn ar gyfrif arall a oedd sy'n debygol o fod wedi bod mewn tor-data. Mae ailddefnyddio manylion yn peryglu'ch holl gyfrifon. Newid y cyfrinair hwn.
+# Variables:
+#   $hostname (String) - The hostname of the website associated with the login, e.g. "example.com"
+about-logins-vulnerable-alert-link = Mynd i { $hostname }
+about-logins-vulnerable-alert-learn-more-link = Dysgu rhagor
+
+## Error Messages
+
+# This is an error message that appears when a user attempts to save
+# a new login that is identical to an existing saved login.
+# Variables:
+#   $loginTitle (String) - The title of the website associated with the login.
+about-logins-error-message-duplicate-login-with-link = Mae cofnod ar gyfer { $loginTitle } gyda'r enw defnyddiwr hwnnw eisoes yn bodoli. <a data-l10n-name="duplicate-link"> Ewch i'r cofnod presennol? </a>
+# This is a generic error message.
+about-logins-error-message-default = Digwyddodd gwall wrth geisio gadw'r cyfrinair hwn.
+
+## Login Export Dialog
+
+# Title of the file picker dialog
+about-logins-export-file-picker-title = Allforio Ffeil Mewngofnodion
+# The default file name shown in the file picker when exporting saved logins.
+# This must end in .csv
+about-logins-export-file-picker-default-filename = mewngofnodion.csv
+about-logins-export-file-picker-export-button = Allforio
+# A description for the .csv file format that may be shown as the file type
+# filter by the operating system.
+about-logins-export-file-picker-csv-filter-title =
+    { PLATFORM() ->
+        [macos] Dogfen CSV
+       *[other] Ffeil CSV
+    }
+
+## Login Import Dialog
+
+# Title of the file picker dialog
+about-logins-import-file-picker-title = Allforio Ffeil Mewngofnodion
+about-logins-import-file-picker-import-button = Mewnforio
+# A description for the .csv file format that may be shown as the file type
+# filter by the operating system.
+about-logins-import-file-picker-csv-filter-title =
+    { PLATFORM() ->
+        [macos] Dogfen CSV
+       *[other] Ffeil CSV
+    }
+# A description for the .tsv file format that may be shown as the file type
+# filter by the operating system. TSV is short for 'tab separated values'.
+about-logins-import-file-picker-tsv-filter-title =
+    { PLATFORM() ->
+        [macos] Dogfen TSV
+       *[other] Ffeil TSV
+    }
+
+##
+## Variables:
+##  $count (number) - The number of affected elements
+
+about-logins-import-dialog-title = Wedi Cwblhau Mewnforio
+about-logins-import-dialog-items-added =
+    { $count ->
+        [zero] <span>Ychwanegwyd mewngofnodion newydd:</span> <span data-l10n-name="count">{ $count }</span>
+        [one] <span>Ychwanegwyd mewngofnodion newydd:</span> <span data-l10n-name="count">{ $count }</span>
+        [two] <span>Ychwanegwyd mewngofnodion newydd:</span> <span data-l10n-name="count">{ $count }</span>
+        [few] <span>Ychwanegwyd mewngofnodion newydd:</span> <span data-l10n-name="count">{ $count }</span>
+        [many] <span>Ychwanegwyd mewngofnodion newydd:</span> <span data-l10n-name="count">{ $count }</span>
+       *[other] <span>Ychwanegwyd mewngofnodion newydd:</span> <span data-l10n-name="count">{ $count }</span>
+    }
+about-logins-import-dialog-items-modified =
+    { $count ->
+        [zero] <span>Diweddarwyd mewngofnodi presennol:</span> <span data-l10n-name="count">{ $count }</span>
+        [one] <span>Diweddarwyd mewngofnodi presennol:</span> <span data-l10n-name="count">{ $count }</span>
+        [two] <span>Diweddarwyd mewngofnodi presennol:</span> <span data-l10n-name="count">{ $count }</span>
+        [few] <span>Diweddarwyd mewngofnodi presennol:</span> <span data-l10n-name="count">{ $count }</span>
+        [many] <span>Diweddarwyd mewngofnodi presennol:</span> <span data-l10n-name="count">{ $count }</span>
+       *[other] <span>Diweddarwyd mewngofnodi presennol:</span> <span data-l10n-name="count">{ $count }</span>
+    }
+about-logins-import-dialog-items-no-change =
+    { $count ->
+        [zero] <span>Mewngofnodion dyblyg wedi'u darganfod: </span> <span data-l10n-name="count">{ $count }</span><span data-l10n-name="meta">(heb ei fewnforio)</span>
+        [one] <span>Mewngofnodion dyblyg wedi'u darganfod: </span> <span data-l10n-name="count">{ $count }</span><span data-l10n-name="meta">(heb ei fewnforio)</span>
+        [two] <span>Mewngofnodion dyblyg wedi'u darganfod: </span> <span data-l10n-name="count">{ $count }</span><span data-l10n-name="meta">(heb ei fewnforio)</span>
+        [few] <span>Mewngofnodion dyblyg wedi'u darganfod: </span> <span data-l10n-name="count">{ $count }</span><span data-l10n-name="meta">(heb ei fewnforio)</span>
+        [many] <span>Mewngofnodion dyblyg wedi'u darganfod: </span> <span data-l10n-name="count">{ $count }</span><span data-l10n-name="meta">(heb ei fewnforio)</span>
+       *[other] <span>Mewngofnodion dyblyg wedi'u darganfod: </span> <span data-l10n-name="count">{ $count }</span><span data-l10n-name="meta">(heb ei fewnforio)</span>
+    }
+about-logins-import-dialog-items-error =
+    { $count ->
+        [zero] <span>Gwallau:</span> <span data-l10n-name="count">{ $count }</span><span data-l10n-name="meta">(heb ei fewnforio)</span>
+        [one] <span>Gwallau:</span> <span data-l10n-name="count">{ $count }</span><span data-l10n-name="meta">(heb ei fewnforio)</span>
+        [two] <span>Gwallau:</span> <span data-l10n-name="count">{ $count }</span><span data-l10n-name="meta">(heb ei fewnforio)</span>
+        [few] <span>Gwallau:</span> <span data-l10n-name="count">{ $count }</span><span data-l10n-name="meta">(heb ei fewnforio)</span>
+        [many] <span>Gwallau:</span> <span data-l10n-name="count">{ $count }</span><span data-l10n-name="meta">(heb ei fewnforio)</span>
+       *[other] <span>Gwallau:</span> <span data-l10n-name="count">{ $count }</span><span data-l10n-name="meta">(heb ei fewnforio)</span>
+    }
+about-logins-import-dialog-done = Gorffen
+about-logins-import-dialog-error-title = Gwall Mewnforio
+about-logins-import-dialog-error-conflicting-values-title = Gwerthoedd Lluosog sy'n Gwrthdaro mewn Un Mewngofnod
+about-logins-import-dialog-error-conflicting-values-description = Er enghraifft: enwau defnyddwyr lluosog, cyfrineiriau, URLau, ac ati ar gyfer un mewngofnod.
+about-logins-import-dialog-error-file-format-title = Mater Fformat Ffeil
+about-logins-import-dialog-error-file-format-description = Penynnau colofnau anghywir neu coll. Gwnewch yn siŵr fod y ffeil yn cynnwys colofnau enw defnyddiwr, cyfrinair ac URL.
+about-logins-import-dialog-error-file-permission-title = Methu Darllen y Ffeil
+about-logins-import-dialog-error-file-permission-description = Nid oes gan { -brand-short-name } ganiatâd i ddarllen y ffeil. Ceisiwch newid caniatâd y ffeil.
+about-logins-import-dialog-error-unable-to-read-title = Methu Didoli'r Ffeil
+about-logins-import-dialog-error-unable-to-read-description = Gwnewch yn siŵr eich bod wedi dewis ffeil CSV neu TSV.
+about-logins-import-dialog-error-no-logins-imported = Heb fewnforio unrhyw fewngofnodion
+about-logins-import-dialog-error-learn-more = Dysgu rhagor
+about-logins-import-dialog-error-try-import-again = Ceisiwch Fewnforio Eto…
+about-logins-import-dialog-error-cancel = Diddymu
+about-logins-import-report-title = Crynodeb Mewnforio
+about-logins-import-report-description = Mewngofnodion a chyfrineiriau wedi'u mewnforio i { -brand-short-name }.
+#
+# Variables:
+#  $number (number) - The number of the row
+about-logins-import-report-row-index = Rhes { $number }
+about-logins-import-report-row-description-no-change = Dyblyg: Cydweddiad union o'r mewngofnod presennol
+about-logins-import-report-row-description-modified = Wedi diweddaru'r mewngofnod presennol
+about-logins-import-report-row-description-added = Ychwanegwyd mewngofnod newydd
+about-logins-import-report-row-description-error = Gwall: Maes ar goll
+
+##
+## Variables:
+##  $field (String) - The name of the field from the CSV file for example url, username or password
+
+about-logins-import-report-row-description-error-multiple-values = Gwall: Gwerthoedd lluosog ar gyfer { $field }
+about-logins-import-report-row-description-error-missing-field = Gwall: { $field } ar goll
+
+##
+## Variables:
+##  $count (number) - The number of affected elements
+
+about-logins-import-report-added =
+    { $count ->
+        [zero] <div data-l10n-name="count">{ $count }</div><div data-l10n-name="details"> Mewngofnodion newydd wedi'u hychwanegu</div>
+        [one] <div data-l10n-name="count">{ $count }</div><div data-l10n-name="details">Mewngofnod newydd wedi'i ychwanegu</div>
+        [two] <div data-l10n-name="count">{ $count }</div><div data-l10n-name="details">Fewngofnod newydd wedi'u hychwanegu</div>
+        [few] <div data-l10n-name="count">{ $count }</div><div data-l10n-name="details">Mewngofnod newydd wedi'u hychwanegu</div>
+        [many] <div data-l10n-name="count">{ $count }</div><div data-l10n-name="details">Mewngofnod newydd wedi'u hychwanegu</div>
+       *[other] <div data-l10n-name="count">{ $count }</div><div data-l10n-name="details">Mewngofnod newydd wedi'u hychwanegu</div>
+    }
+about-logins-import-report-modified =
+    { $count ->
+        [zero] <div data-l10n-name="count">{ $count }</div><div data-l10n-name="details">Mewngofnodion newydd wedi'u diweddaru</div>
+        [one] <div data-l10n-name="count">{ $count }</div><div data-l10n-name="details">Mewngofnod newydd wedi'i ddiweddaru</div>
+        [two] <div data-l10n-name="count">{ $count }</div><div data-l10n-name="details">Fewngofnod newydd wedi'u diweddaru</div>
+        [few] <div data-l10n-name="count">{ $count }</div><div data-l10n-name="details">Mewngofnod newydd wedi'u diweddaru</div>
+        [many] <div data-l10n-name="count">{ $count }</div><div data-l10n-name="details">Mewngofnod newydd wedi'u diweddaru</div>
+       *[other] <div data-l10n-name="count">{ $count }</div><div data-l10n-name="details">Mewngofnod newydd wedi'u diweddaru</div>
+    }
+about-logins-import-report-no-change =
+    { $count ->
+        [zero] <div data-l10n-name="count">{ $count }</div> <div data-l10n-name="details">Mewngofnodion dyblyg</div> <div data-l10n-name="not-imported">(heb eu mewnforio)</div>
+        [one] <div data-l10n-name="count">{ $count }</div> <div data-l10n-name="details">Mewngofnod dyblyg</div> <div data-l10n-name="not-imported">(heb ei fewnforio)</div>
+        [two] <div data-l10n-name="count">{ $count }</div> <div data-l10n-name="details">Fewngofnod dyblyg</div> <div data-l10n-name="not-imported">(heb eu mewnforio)</div>
+        [few] <div data-l10n-name="count">{ $count }</div> <div data-l10n-name="details">Fewngofnod dyblyg</div> <div data-l10n-name="not-imported">(heb eu mewnforio)</div>
+        [many] <div data-l10n-name="count">{ $count }</div> <div data-l10n-name="details">Fewngofnod dyblyg</div> <div data-l10n-name="not-imported">(heb eu mewnforio)</div>
+       *[other] <div data-l10n-name="count">{ $count }</div> <div data-l10n-name="details">Fewngofnod dyblyg</div> <div data-l10n-name="not-imported">(heb eu mewnforio)</div>
+    }
+about-logins-import-report-error =
+    { $count ->
+        [zero] <div data-l10n-name="count">{ $count }</div> <div data-l10n-name="details">Gwallau</div> <div data-l10n-name="not-imported">(heb eu mewnforio)</div>
+        [one] <div data-l10n-name="count">{ $count }</div> <div data-l10n-name="details">Gwall</div> <div data-l10n-name="not-imported">(heb ei fewnforio)</div>
+        [two] <div data-l10n-name="count">{ $count }</div> <div data-l10n-name="details">Wall</div> <div data-l10n-name="not-imported">(heb eu mewnforio)</div>
+        [few] <div data-l10n-name="count">{ $count }</div> <div data-l10n-name="details">Gwall</div> <div data-l10n-name="not-imported">(heb eu mewnforio)</div>
+        [many] <div data-l10n-name="count">{ $count }</div> <div data-l10n-name="details">Gwall</div> <div data-l10n-name="not-imported">(heb eu mewnforio)</div>
+       *[other] <div data-l10n-name="count">{ $count }</div> <div data-l10n-name="details">Gwall</div> <div data-l10n-name="not-imported">(heb eu mewnforio)</div>
+    }
+
+## Logins import report page
+
+about-logins-import-report-page-title = Mewnforio Adroddiad Cryno
diff --git a/l10n-cy/browser/browser/aboutPocket.ftl b/l10n-cy/browser/browser/aboutPocket.ftl
new file mode 100644
index 0000000000..1d94e25cfb
--- /dev/null
+++ b/l10n-cy/browser/browser/aboutPocket.ftl
@@ -0,0 +1,77 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+### Pocket button panel strings for about:pocket-saved, about:pocket-signup, and about:pocket-home
+
+
+## about:pocket-saved panel
+
+# Placeholder text for tag input
+pocket-panel-saved-add-tags =
+    .placeholder = Ychwanegu Tagiau
+pocket-panel-saved-error-generic = Bu gwall wrth geisio cadw i { -pocket-brand-name }.
+pocket-panel-saved-error-tag-length = Mae tagiau wedi eu cyfyngu i 25 nod
+pocket-panel-saved-error-only-links = Dim ond dolenni y mae modd eu cadw
+pocket-panel-saved-error-not-saved = Heb Gadw'r Dudalen
+pocket-panel-saved-error-no-internet = Rhaid eich bod wedi cysylltu i'r rhyngrwyd i gadw i { -pocket-brand-name }. Cysylltwch â'r Rhyngrwyd a cheisiwch eto.
+pocket-panel-saved-error-remove = Bu gwall wrth geisio tynnu'r dudalen.
+pocket-panel-saved-page-removed = Tudalen wedi ei Thynnu
+pocket-panel-saved-page-saved = Cadwyd i { -pocket-brand-name }
+pocket-panel-saved-page-saved-b = Cadwyd i { -pocket-brand-name }
+pocket-panel-saved-processing-remove = Tynnu Tudalen…
+pocket-panel-saved-removed = Tudalen Wedi'i Thynnu o Fy Rhestr
+pocket-panel-saved-removed-updated = Tudalen wedi'i thynnu o'r Cadw
+pocket-panel-saved-processing-tags = Ychwanegu tagiau…
+pocket-panel-saved-remove-page = Tynnu Tudalen
+pocket-panel-saved-save-tags = Cadw
+pocket-panel-saved-saving-tags = Cadw…
+pocket-panel-saved-suggested-tags = Awgrymiadau o Dagiau
+pocket-panel-saved-tags-saved = Ychwanegwyd Tagiau
+pocket-panel-signup-view-list = Gweld Rhestr
+# This is displayed above a field where the user can add tags
+pocket-panel-signup-add-tags = Ychwanegu Tagiau:
+
+## about:pocket-signup panel
+
+pocket-panel-signup-already-have = Eisoes yn ddefnyddiwr { -pocket-brand-name }?
+pocket-panel-signup-learn-more = Dysgu Rhagor
+pocket-panel-signup-login = Mewngofnodi
+pocket-panel-signup-signup-email = Ymunwch drwy e-bost
+pocket-panel-signup-signup-cta = Ymunwch â { -pocket-brand-name }. Mae am ddim.
+pocket-panel-signup-signup-firefox = Ymuno drwy { -brand-product-name }
+pocket-panel-signup-tagline = Cadw erthyglau a fideos o { -brand-product-name } i'w gweld yn { -pocket-brand-name } ar unrhyw ddyfais, ar unrhyw adeg.
+pocket-panel-signup-tagline-story-one = Cliciwch Fotwm { -pocket-brand-name } i gadw unrhyw erthygl, fideo neu dudalen o { -brand-product-name }.
+pocket-panel-signup-tagline-story-two = Gweld yn { -pocket-brand-name } ar unrhyw ddyfais, ar unrhyw adeg.
+pocket-panel-signup-cta-a-fix = Eich botwm cadw ar gyfer y rhyngrwyd.
+pocket-panel-signup-cta-b = Cliciwch y botwm { -pocket-brand-name } i gadw erthyglau, fideos a dolenni. Edrychwch ar eich rhestr ar unrhyw ddyfais, unrhyw bryd.
+pocket-panel-signup-cta-b-updated = Cliciwch y botwm { -pocket-brand-name } i gadw erthyglau, fideos a dolenni. Gallwch weld eich cadw ar unrhyw ddyfais, unrhyw bryd.
+pocket-panel-signup-cta-b-short = Cliciwch y botwm { -pocket-brand-name } i gadw erthyglau, fideos a dolenni.
+pocket-panel-signup-cta-c = Edrychwch ar eich rhestr ar unrhyw ddyfais, ar unrhyw bryd.
+pocket-panel-signup-cta-c-updated = Gweld eich cadw ar unrhyw ddyfais, unrhyw bryd.
+
+## about:pocket-home panel
+
+pocket-panel-home-my-list = Fy Rhestr
+pocket-panel-home-welcome-back = Croeso Nôl
+pocket-panel-home-paragraph = Gallwch ddefnyddio { -pocket-brand-name } i archwilio a chadw tudalennau gwe, erthyglau, fideos, podlediadau neu fynd yn ôl at yr hyn rydych chi wedi bod yn ei ddarllen.
+pocket-panel-home-explore-popular-topics = Archwilio Pynciau Poblogaidd
+pocket-panel-home-discover-more = Darganfod Rhagor
+pocket-panel-home-explore-more = Archwilio
+pocket-panel-home-most-recent-saves = Dyma beth rydych wedi eu cadw'n ddiweddar:
+pocket-panel-home-most-recent-saves-loading = Yn llwytho erthyglau diweddar wedi'u cadw …
+pocket-panel-home-new-user-cta = Cliciwch y botwm { -pocket-brand-name } i gadw erthyglau, fideos a dolenni.
+pocket-panel-home-new-user-message = Gweld beth rydych wedi eu cadw'n ddiweddar:
+
+## Pocket panel header component
+
+pocket-panel-header-my-list = Gweld Fy Rhestr
+pocket-panel-header-my-saves = Gweld Fy Nghadw
+pocket-panel-header-sign-in = Mewngofnodi
+
+## Pocket panel buttons
+
+pocket-panel-button-show-all = Dangos y Cyfan
+pocket-panel-button-activate = Agor { -pocket-brand-name } yn { -brand-product-name }
+pocket-panel-button-remove = Tynnu
diff --git a/l10n-cy/browser/browser/aboutPolicies.ftl b/l10n-cy/browser/browser/aboutPolicies.ftl
new file mode 100644
index 0000000000..f09e180c9f
--- /dev/null
+++ b/l10n-cy/browser/browser/aboutPolicies.ftl
@@ -0,0 +1,17 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+about-policies-title = Polisïau Mentrau
+
+# 'Active' is used to describe the policies that are currently active
+active-policies-tab = Gweithredol
+errors-tab = Gwallau
+documentation-tab = Dogfennaeth
+
+no-specified-policies-message = Mae'r gwasanaeth Polisïau Menter yn weithredol ond nid oes unrhyw bolisïau wedi'u galluogi.
+inactive-message = Mae'r gwasanaeth Polisïau Menter yn anweithredol.
+
+policy-name = Enw Polisi
+policy-value = Gwerth Polisi
+policy-errors = Gwallau Polisi
diff --git a/l10n-cy/browser/browser/aboutPrivateBrowsing.ftl b/l10n-cy/browser/browser/aboutPrivateBrowsing.ftl
new file mode 100644
index 0000000000..f23623252e
--- /dev/null
+++ b/l10n-cy/browser/browser/aboutPrivateBrowsing.ftl
@@ -0,0 +1,66 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+privatebrowsingpage-open-private-window-label = Agor Ffenestr Breifat
+    .accesskey = F
+about-private-browsing-search-placeholder = Chwilio'r We
+about-private-browsing-info-title = Rydych mewn Ffenestr Breifat
+about-private-browsing-search-btn =
+    .title = Chwilio'r we
+# Variables
+#  $engine (String): the name of the user's default search engine
+about-private-browsing-handoff =
+    .title = Chwilio gyda { $engine } neu roi cyfeiriad
+about-private-browsing-handoff-no-engine =
+    .title = Chwilio neu roi cyfeiriad
+# Variables
+#  $engine (String): the name of the user's default search engine
+about-private-browsing-handoff-text = Chwilio gyda { $engine } neu roi cyfeiriad
+about-private-browsing-handoff-text-no-engine = Chwilio neu roi cyfeiriad
+about-private-browsing-not-private = Nid ydych mewn ffenestr breifat ar hyn o bryd.
+about-private-browsing-info-description-private-window = Ffenestr breifat: Mae { -brand-short-name } yn clirio'ch hanes chwilio a phori pan fyddwch yn cau pob ffenestr breifat. Nid yw hyn yn eich gwneud chi'n anhysbys.
+about-private-browsing-info-description-simplified = Mae { -brand-short-name } yn clirio'ch hanes chwilio a phori pan fyddwch yn cau pob ffenestr breifat, ond nid yw hyn yn eich gwneud chi'n anhysbys.
+about-private-browsing-learn-more-link = Dysgu rhagor
+
+about-private-browsing-hide-activity = Cuddiwch eich gweithgaredd a'ch lleoliad, ym mhobman rydych chi'n pori
+about-private-browsing-get-privacy = Cael diogelwch preifatrwydd ym mhobman rydych chi'n pori
+about-private-browsing-hide-activity-1 = Cuddio gweithgaredd pori a lleoliad gyda { -mozilla-vpn-brand-name }. Mae un clic yn creu cysylltiad diogel, hyd yn oed ar Wi-Fi cyhoeddus.
+about-private-browsing-prominent-cta = Cadwch yn breifat gyda { -mozilla-vpn-brand-name }
+
+about-private-browsing-focus-promo-cta = Llwytho { -focus-brand-name } i Lawr
+about-private-browsing-focus-promo-header = { -focus-brand-name }: Pori preifat wrth fynd
+about-private-browsing-focus-promo-text = Mae ein ap symudol pori preifat pwrpasol yn clirio'ch hanes a'ch cwcis bob tro.
+
+## The following strings will be used for experiments in Fx99 and Fx100
+
+about-private-browsing-focus-promo-header-b = Ewch â phori preifat i'ch ffôn
+about-private-browsing-focus-promo-text-b = Defnyddiwch { -focus-brand-name } ar gyfer y chwilio preifat hynny nad ydych am i'ch prif borwr symudol eu gweld.
+about-private-browsing-focus-promo-header-c = Preifatrwydd uwch ar ffôn symudol
+about-private-browsing-focus-promo-text-c = Mae { -focus-brand-name } yn clirio'ch hanes bob tro tra'n rhwystro hysbysebion a thracwyr.
+
+# This string is the title for the banner for search engine selection
+# in a private window.
+# Variables:
+#   $engineName (String) - The engine name that will currently be used for the private window.
+about-private-browsing-search-banner-title = { $engineName } yw eich peiriant chwilio rhagosodedig mewn Ffenestri Preifat
+about-private-browsing-search-banner-description =
+    { PLATFORM() ->
+        [windows] I ddewis peiriant chwilio gwahanol ewch i <a data-l10n-name="link-options">Opsiynau</a>
+       *[other] I ddewis peiriant chwilio gwahanol ewch i <a data-l10n-name="link-options">Dewisiadau</a>
+    }
+about-private-browsing-search-banner-close-button =
+    .aria-label = Cau
+
+about-private-browsing-promo-close-button =
+    .title = Cau
+
+## Strings used in a “pin promotion” message, which prompts users to pin a private window
+
+about-private-browsing-pin-promo-header = Rhyddid pori preifat mewn un clic
+about-private-browsing-pin-promo-link-text =
+    { PLATFORM() ->
+        [macos] Ei Gadw yn y Doc
+       *[other] Pinio i'r bar tasgau
+    }
+about-private-browsing-pin-promo-title = Dim cwcis na hanes wedi'u cadw, o'ch bwrdd gwaith. Porwch fel nad oes neb yn gwylio.
diff --git a/l10n-cy/browser/browser/aboutRestartRequired.ftl b/l10n-cy/browser/browser/aboutRestartRequired.ftl
new file mode 100644
index 0000000000..570eb0c804
--- /dev/null
+++ b/l10n-cy/browser/browser/aboutRestartRequired.ftl
@@ -0,0 +1,10 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+restart-required-title = Mae Angen Ail Gychwyn
+restart-required-heading = Ailgychwyn i Barhau i Ddefnyddio { -brand-short-name }
+restart-required-intro = Dechreuwyd diweddaru { -brand-short-name } yn y cefndir. Bydd angen i chi ailgychwyn i orffen y diweddariad.
+window-restoration-info = Bydd eich ffenestri a'ch tabiau'n cael eu hadfer yn gyflym, ond nid y rhai preifat.
+
+restart-button-label = Ailgychwyn { -brand-short-name }
diff --git a/l10n-cy/browser/browser/aboutRobots.ftl b/l10n-cy/browser/browser/aboutRobots.ftl
new file mode 100644
index 0000000000..e8fc0e2c7f
--- /dev/null
+++ b/l10n-cy/browser/browser/aboutRobots.ftl
@@ -0,0 +1,29 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+### These strings are used in the about:robots page, which ties in with the
+### robots theme used in the Firefox 3 Beta 2/3 first run pages.
+### They're just meant to be fun and whimsical, with references to some geeky
+### but well-known robots in movies and books. Be creative with translations!
+
+# Nonsense line from the movie "The Day The Earth Stood Still". No translation needed.
+page-title = Gort! Klaatu barada nikto!
+# Movie: Logan's Run... Box (cyborg): "Welcome Humans! I am ready for you."
+error-title-text = Croeso Ddynionach!
+# Movie: The Day The Earth Stood Still. Spoken by Klaatu.
+error-short-desc-text = Rydym wedi dod i'ch cyfarfod mewn heddwch ac ewyllys da!
+# Various books by Isaac Asimov. http://en.wikipedia.org/wiki/Three_Laws_of_Robotics
+error-long-desc1 = Nid yw robotiaid yn cael anafu dynion neu drwy ddiffyg gweithredu gadel iddynt gael eu niweidio.
+# Movie: Blade Runner. Batty: "I've seen things you people wouldn’t believe..."
+error-long-desc2 = Mae robotiaid wedi gweld pethau fyddwch chi ddim yn ei gredu.
+# Book: Hitchhiker’s Guide To The Galaxy. What the Sirius Cybernetics Corporation calls robots.
+error-long-desc3 = Robot yw dy Ffrind Plastig sy'n Hwyl a Sbort.
+# TV: Futurama. Bender's first line is "Bite my shiny metal ass."
+error-long-desc4 = Mae gan robotiaid rhan ôl metel disglair na ddylid ei gnoi.
+# TV: Battlestar Galactica (2004 series). From the opening text.
+error-trailer-desc-text = Ac mae ganddyn nhw gynllun.
+# Book: Hitchhiker's Guide To The Galaxy. Arthur presses a button and it warns him.
+error-try-again = Ceisiwch eto
+    .label2 = Paid pwyso'r botwm yma eto.
diff --git a/l10n-cy/browser/browser/aboutSessionRestore.ftl b/l10n-cy/browser/browser/aboutSessionRestore.ftl
new file mode 100644
index 0000000000..07e7315f99
--- /dev/null
+++ b/l10n-cy/browser/browser/aboutSessionRestore.ftl
@@ -0,0 +1,51 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+restore-page-tab-title = Adfer y Sesiwn
+
+# The title is intended to be apologetic and disarming, expressing dismay
+# and regret that we are unable to restore the session for the user
+restore-page-error-title = Ymddiheuriadau. Rydym yn cael anhawster adfer eich tudalennau.
+restore-page-problem-desc = Rydym yn cael anhawster adfer eich sesiwn pori diwethaf. Dewiswch Adfer Sesiwn er mwyn ceisio eto.
+restore-page-try-this = Dal dim yn gallu adfer eich sesiwn? Weithiau bydd tab yn achosi problem. Edrychwch ar dabiau blaenorol, tynnwch y marc ticio o'r tabiau does dim angen eu hadfer ac yna adfer.
+
+restore-page-hide-tabs = Cuddio'r Tabiau Blaenorol
+restore-page-show-tabs = Edrych ar Dabiau Blaenorol
+
+# When tabs are distributed across multiple windows, this message is used as a
+# header above the group of tabs for each window.
+#
+# Variables:
+#    $windowNumber: Progressive number associated to each window
+restore-page-window-label = Ffenestr { $windowNumber }
+
+restore-page-restore-header =
+    .label = Adfer
+
+restore-page-list-header =
+    .label = Ffenestri a Thabiau
+
+restore-page-try-again-button =
+    .label = Adfer y Sesiwn
+    .accesskey = A
+
+restore-page-close-button =
+    .label = Cychwyn Sesiwn Newydd
+    .accesskey = N
+
+## The following strings are used in about:welcomeback
+
+welcome-back-tab-title = Llwyddiant!
+welcome-back-page-title = Llwyddiant!
+welcome-back-page-info = Mae { -brand-short-name } yn barod i fynd.
+
+welcome-back-restore-button =
+    .label = Ffwrdd â ni!
+    .accesskey = F
+
+welcome-back-restore-all-label = Adfer pob ffenestr a thab
+welcome-back-restore-some-label = Adfer dim ond y rhai rydych eu heisiau
+
+welcome-back-page-info-link = Mae eich ychwanegion a'ch cyfaddasu wedi eu tynnu ac mae gosodiadau eich porwr wedi eu hadfer i'w rhagosodiad. Os nad yw hyn wedi trwsio eich anhawster, <a data-l10n-name="link-more">dysgu rhagor am beth fedrwch ei wneud.</a>
+
diff --git a/l10n-cy/browser/browser/aboutTabCrashed.ftl b/l10n-cy/browser/browser/aboutTabCrashed.ftl
new file mode 100644
index 0000000000..3014ff147c
--- /dev/null
+++ b/l10n-cy/browser/browser/aboutTabCrashed.ftl
@@ -0,0 +1,22 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+crashed-title = Adroddwr chwalu tab
+crashed-close-tab-button = Cau Tab
+crashed-restore-tab-button = Adfer y Tab Hwn
+crashed-restore-all-button = Adfer Pob Tab Chwalwyd
+crashed-header = Ach. Mae eich tab newydd chwalu.
+crashed-offer-help = Gallwn ni helpu!
+crashed-single-offer-help-message = Dewiswch { crashed-restore-tab-button } i ail lwytho'r dudalen.
+crashed-multiple-offer-help-message = Dewiswch { crashed-restore-tab-button } neu { crashed-restore-all-button } i ail lwytho'r dudalen/tudalennau.
+crashed-request-help = A wnewch chi ein helpu ni?
+crashed-request-help-message = Mae adroddiadau chwalu yn caniatáu i ni ddadansoddi anawsterau a gwneud { -brand-short-name } yn well.
+crashed-request-report-title = Adrodd am y tab
+crashed-send-report-2 = Anfonwch adroddiad chwalu awtomataidd fel bod modd i ni drwsio materion fel hyn.
+crashed-comment =
+    .placeholder = Sylwadau dewisol (sylwadau yn weladwy'n gyhoeddus)
+crashed-include-URL-2 = Cofiwch gynnwys URLau gwefannau roeddech arnynt pan chwalodd { -brand-short-name }.
+crashed-report-sent = Mae'r adroddiad chwalu wedi ei gyflwyno: diolch am gynorthwyo i wneud { -brand-short-name } yn well!
+crashed-request-auto-submit-title = Gofyn am dabiau cefndir
+crashed-auto-submit-checkbox-2 = Diweddarwch y dewisiadau i gyflwyno adroddiadau'n awtomatig pan fydd { -brand-short-name } yn chwalu.
diff --git a/l10n-cy/browser/browser/aboutUnloads.ftl b/l10n-cy/browser/browser/aboutUnloads.ftl
new file mode 100644
index 0000000000..e24b338522
--- /dev/null
+++ b/l10n-cy/browser/browser/aboutUnloads.ftl
@@ -0,0 +1,46 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+### Strings used in about:unloads, allowing users to manage the "tab unloading"
+### feature.
+
+about-unloads-page-title = Dadlwytho Tabiau
+about-unloads-intro =
+    Mae gan { -brand-short-name } nodwedd sy'n dadlwytho tabiau'n
+    awtomatig i atal y rhaglen rhag chwalu oherwydd cof annigonol pan
+    fydd maint cof y system sydd ar gael yn isel. Mae'r tab nesaf i'w
+    ddadlwytho yw cael ei ddewis yn seiliedig ar briodoleddau lluosog.
+    Mae'r dudalen hon yn dangos sut mae { -brand-short-name } yn
+    blaenoriaethu tabiau a pha dab fydd yn cael ei ddadlwytho pan
+    fydd dadlwytho tab yn cael ei gychwyn. Gallwch gychwyn dadlwytho
+    tab â llaw trwy glicio ar y botwm <em>Dadlwytho</em> isod.
+
+# The link points to a Firefox documentation page, only available in English,
+# with title "Tab Unloading"
+about-unloads-learn-more =
+    Gweler <a data-l10n-name="doc-link">Dadlwytho Tab</a> i ddysgu rhagor am
+    y nodwedd a'r dudalen hon.
+
+about-unloads-last-updated = Wedi'i ddiweddaru ddiwethaf: { DATETIME($date, year: "numeric", month: "numeric", day: "numeric", hour: "numeric", minute: "numeric", second: "numeric", hour12: "false") }
+about-unloads-button-unload = Llwytho i fyny
+    .title = Llwytho tab gyda'r flaenoriaeth uchaf i fyny
+about-unloads-no-unloadable-tab = Nid oes tabiau nad oes modd eu dadlwytho.
+
+about-unloads-column-priority = Blaenoriaeth
+about-unloads-column-host = Gwesteiwr
+about-unloads-column-last-accessed = Cyrchwyd Diwethaf
+about-unloads-column-weight = Pwysau Sylfaenol
+    .title = Mae tabiau'n cael eu didoli yn ôl y gwerth yma, sy'n dod o rhai priodoleddau arbennig megis gwneud sŵn, WebRTC, ac ati.
+about-unloads-column-sortweight = Pwysau Eilaidd
+    .title = Os ar gael, mae tabiau'n cael eu didoli gan y gwerth hwn ar ôl eu didoli yn ôl y pwysau sylfaenol. Mae'r gwerth yn dod o ddefnydd cof y tab a chyfrif y prosesau.
+about-unloads-column-memory = Cof
+    .title = Amcan o ddefnydd cof y tab
+about-unloads-column-processes = IDau Prosesau
+    .title = IDau o brosesau sy'n gwesteio cynnwys y tab
+
+about-unloads-last-accessed = { DATETIME($date, year: "numeric", month: "numeric", day: "numeric", hour: "numeric", minute: "numeric", second: "numeric", hour12: "false") }
+about-unloads-memory-in-mb = { NUMBER($mem, maxFractionalUnits: 2) } MB
+about-unloads-memory-in-mb-tooltip =
+    .title = { NUMBER($mem, maxFractionalUnits: 2) } MB
diff --git a/l10n-cy/browser/browser/accounts.ftl b/l10n-cy/browser/browser/accounts.ftl
new file mode 100644
index 0000000000..bd1d72d18c
--- /dev/null
+++ b/l10n-cy/browser/browser/accounts.ftl
@@ -0,0 +1,17 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# Used as the FxA toolbar menu item value when user has not
+# finished setting up an account.
+account-finish-account-setup = Gorffen Creu Cyfrif
+
+# Used as the FxA toolbar menu item title when the user
+# needs to reconnect their account.
+account-disconnected2 = Datgysylltwyd y cyfrif
+
+# Menu item that sends a tab to all synced devices.
+account-send-to-all-devices = Anfon i Bob Dyfais
+
+# Menu item that links to the Firefox Accounts settings for connected devices.
+account-manage-devices = Rheoli Dyfeisiadau…
diff --git a/l10n-cy/browser/browser/allTabsMenu.ftl b/l10n-cy/browser/browser/allTabsMenu.ftl
new file mode 100644
index 0000000000..9f23e3b39c
--- /dev/null
+++ b/l10n-cy/browser/browser/allTabsMenu.ftl
@@ -0,0 +1,17 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# "Search" is a verb, as in "Search through tabs".
+all-tabs-menu-search-tabs =
+    .label = Chwilio'r Tabiau
+
+all-tabs-menu-new-user-context =
+    .label = Tab Cynhwysydd Newydd
+
+all-tabs-menu-hidden-tabs =
+    .label = Tabiau Cudd
+
+all-tabs-menu-manage-user-context =
+    .label = Rheoli Cynwysyddion
+    .accesskey = R
diff --git a/l10n-cy/browser/browser/appExtensionFields.ftl b/l10n-cy/browser/browser/appExtensionFields.ftl
new file mode 100644
index 0000000000..10a350958f
--- /dev/null
+++ b/l10n-cy/browser/browser/appExtensionFields.ftl
@@ -0,0 +1,31 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+## Theme names and descriptions used in the Themes panel in about:addons
+
+# "Auto" is short for automatic. It can be localized without limitations.
+extension-default-theme-name-auto = Thema'r system — awto
+extension-default-theme-description = Dilynwch osodiad y system weithredu ar gyfer botymau, dewislenni a ffenestri.
+
+extension-firefox-compact-light-name = Golau
+extension-firefox-compact-light-description = Thema gyda chynllun lliw golau.
+
+extension-firefox-compact-dark-name = Tywyll
+extension-firefox-compact-dark-description = Thema sydd â chynllun lliw tywyll.
+
+extension-firefox-alpenglow-name = Firefox Alpenglow
+extension-firefox-alpenglow-description = Defnyddiwch wedd liwgar ar gyfer botymau, dewislenni, a ffenestri.
+
+## Colorway Themes
+## These themes are variants of a colorway. The colorway is specified in the
+## $colorway-name variable.
+## Variables
+##   $colorway-name (String) The name of a colorway (e.g. Graffiti, Elemental).
+
+extension-colorways-soft-name = { $colorway-name } — Meddal
+extension-colorways-balanced-name = { $colorway-name } — Cytbwys
+# "Bold" is used in the sense of bravery or courage, not in the sense of
+# emphasized text.
+extension-colorways-bold-name = { $colorway-name } — Beiddgar
diff --git a/l10n-cy/browser/browser/appMenuNotifications.ftl b/l10n-cy/browser/browser/appMenuNotifications.ftl
new file mode 100644
index 0000000000..d147269d9a
--- /dev/null
+++ b/l10n-cy/browser/browser/appMenuNotifications.ftl
@@ -0,0 +1,66 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+appmenu-update-available2 =
+    .label = Diweddariad ar gael
+    .buttonlabel = Llwytho i lawr
+    .buttonaccesskey = L
+    .secondarybuttonlabel = Cau
+    .secondarybuttonaccesskey = C
+appmenu-update-available-message2 = Llwythwch y fersiwn ddiweddaraf o { -brand-shorter-name } i lawr.
+appmenu-update-manual2 =
+    .label = Mae diweddariad ar gael
+    .buttonlabel = Llwytho i lawr
+    .buttonaccesskey = L
+    .secondarybuttonlabel = Cau
+    .secondarybuttonaccesskey = C
+appmenu-update-manual-message2 = Methodd { -brand-shorter-name } a ddiweddaru'n awtomatig. Llwythwch y fersiwn newydd i lawr — fyddwch chi ddim yn colli eich gwybodaeth na'ch cyfaddasiadau.
+appmenu-update-unsupported2 =
+    .label = Methu diweddaru
+    .buttonlabel = Dysgu rhagor
+    .buttonaccesskey = D
+    .secondarybuttonlabel = Cau
+    .secondarybuttonaccesskey = C
+appmenu-update-unsupported-message2 = Nid yw'ch system weithredu yn gydnaws â'r fersiwn ddiweddaraf o { -brand-shorter-name }.
+appmenu-update-restart2 =
+    .label = Mae diweddariad ar gael
+    .buttonlabel = Diweddarwch ac ailgychwyn
+    .buttonaccesskey = D
+    .secondarybuttonlabel = Cau
+    .secondarybuttonaccesskey = C
+appmenu-update-restart-message2 = Cael y fersiwn ddiweddaraf o { -brand-shorter-name }. Bydd tabiau a ffenestri sydd ar agor yn cael eu hadfer.
+appmenu-update-other-instance =
+    .label = Nid yw { -brand-shorter-name } yn gallu diweddaru i'r fersiwn diweddaraf.
+    .buttonlabel = Diweddaru { -brand-shorter-name } beth bynnag
+    .buttonaccesskey = D
+    .secondarybuttonlabel = Nid Nawr
+    .secondarybuttonaccesskey = N
+appmenu-update-other-instance-message = Mae diweddariad newydd { -brand-shorter-name } ar gael, ond nid oes modd ei osod oherwydd bod copi arall o { -brand-shorter-name } yn rhedeg. Caewch ef i barhau â'r diweddariad, neu dewiswch ei ddiweddaru beth bynnag (efallai na fydd y copi arall yn gweithio'n iawn nes i chi ei ailgychwyn).
+
+appmenu-addon-private-browsing-installed2 =
+    .buttonlabel = Iawn
+    .buttonaccesskey = I
+appmenu-addon-post-install-message3 = Rheolwch eich estyniadau a'ch themâu trwy'r ddewislen apiau.
+appmenu-addon-post-install-incognito-checkbox =
+    .label = Caniatáu i'r estyniad yma redeg mewn Ffenestri Preifat
+    .accesskey = C
+
+appmenu-new-tab-controlled-changes =
+    .label = Mae eich tab newydd wedi newid.
+    .buttonlabel = Cadw'r Newidiadau
+    .buttonaccesskey = N
+    .secondarybuttonlabel = Rheoli Tabiau Newydd
+    .secondarybuttonaccesskey = R
+appmenu-homepage-controlled-changes =
+    .label = Mae eich tudalen cartref wedi newid.
+    .buttonlabel = Cadw'r Newidiadau
+    .buttonaccesskey = N
+    .secondarybuttonlabel = Rheoli'r Dudalen Cartref
+    .secondarybuttonaccesskey = T
+appmenu-tab-hide-controlled =
+    .label = Mynd i’ch Tabiau Cudd
+    .buttonlabel = Cadw Tabiau’n Gudd
+    .buttonaccesskey = C
+    .secondarybuttonlabel = Analluogi’r Estyniad
+    .secondarybuttonaccesskey = A
diff --git a/l10n-cy/browser/browser/appmenu.ftl b/l10n-cy/browser/browser/appmenu.ftl
new file mode 100644
index 0000000000..e14085cee6
--- /dev/null
+++ b/l10n-cy/browser/browser/appmenu.ftl
@@ -0,0 +1,253 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+## App Menu
+
+appmenuitem-banner-update-downloading =
+    .label = Wrthi'n llwytho diweddariad { -brand-shorter-name } i lawr
+appmenuitem-banner-update-available =
+    .label = Mae diweddariad ar gael — llwytho i lawr nawr
+appmenuitem-banner-update-manual =
+    .label = Mae diweddariad ar gael — llwytho i lawr nawr
+appmenuitem-banner-update-unsupported =
+    .label = Methu diweddaru — mae'r system yn anghydnaws
+appmenuitem-banner-update-restart =
+    .label = Mae diweddariad ar gael — ailgychwyn nawr
+appmenuitem-new-tab =
+    .label = Tab Newydd
+appmenuitem-new-window =
+    .label = Ffenestr Newydd
+appmenuitem-new-private-window =
+    .label = Ffenestr Breifat Newydd
+appmenuitem-history =
+    .label = Hanes
+appmenuitem-downloads =
+    .label = Llwythi
+appmenuitem-passwords =
+    .label = Cyfrineiriau
+appmenuitem-addons-and-themes =
+    .label = Ychwanegion a Themâu
+appmenuitem-print =
+    .label = Argraffu…
+appmenuitem-find-in-page =
+    .label = Canfod ar Dudalen…
+appmenuitem-zoom =
+    .value = Chwyddo
+appmenuitem-more-tools =
+    .label = Rhagor o Offer
+appmenuitem-help =
+    .label = Cymorth
+appmenuitem-exit2 =
+    .label =
+        { PLATFORM() ->
+            [linux] Gadael
+           *[other] Gadael
+        }
+appmenu-menu-button-closed2 =
+    .tooltiptext = Agor Dewislen y Rhaglen
+    .label = { -brand-short-name }
+appmenu-menu-button-opened2 =
+    .tooltiptext = Cau Dewislen y Rhaglen
+    .label = { -brand-short-name }
+# Settings is now used to access the browser settings across all platforms,
+# instead of Options or Preferences.
+appmenuitem-settings =
+    .label = Gosodiadau
+
+## Zoom and Fullscreen Controls
+
+appmenuitem-zoom-enlarge =
+    .label = Chwyddo mewn
+appmenuitem-zoom-reduce =
+    .label = Chwyddo allan
+appmenuitem-fullscreen =
+    .label = Sgrin Lawn
+
+## Firefox Account toolbar button and Sync panel in App menu.
+
+appmenu-remote-tabs-sign-into-sync =
+    .label = Mewngofnodi i Sync…
+appmenu-remote-tabs-turn-on-sync =
+    .label = Cychwyn Sync…
+# This is shown after the tabs list if we can display more tabs by clicking on the button
+appmenu-remote-tabs-showmore =
+    .label = Dangos Rhagor o Dabiau
+    .tooltiptext = Dangos rhagor o dabiau o'r ddyfais hon
+# This is shown beneath the name of a device when that device has no open tabs
+appmenu-remote-tabs-notabs = Dim tabiau agored
+# This is shown when Sync is configured but syncing tabs is disabled.
+appmenu-remote-tabs-tabsnotsyncing = Cychwynnwch gydweddu tabiau er mwyn gweld rhestr o dabiau o'ch dyfeisiau eraill.
+appmenu-remote-tabs-opensettings =
+    .label = Gosodiadau
+# This is shown when Sync is configured but this appears to be the only device attached to
+# the account. We also show links to download Firefox for android/ios.
+appmenu-remote-tabs-noclients = Hoffech chi weld eich tabiau o ddyfeisiau eraill yma?
+appmenu-remote-tabs-connectdevice =
+    .label = Cysylltu Dyfais Arall
+appmenu-remote-tabs-welcome = Gweld rhestr o dabiau o'ch dyfeisiau eraill.
+appmenu-remote-tabs-unverified = Mae angen i'ch cyfrif cael ei gwirio.
+appmenuitem-fxa-toolbar-sync-now2 = Cydweddu Nawr
+appmenuitem-fxa-sign-in = Mewngofnodi i { -brand-product-name }
+appmenuitem-fxa-manage-account = Rheoli Cyfrif
+appmenu-fxa-header2 = { -fxaccount-brand-name }
+# Variables
+# $time (string) - Localized relative time since last sync (e.g. 1 second ago,
+# 3 hours ago, etc.)
+appmenu-fxa-last-sync = Cydweddwyd diwethaf { $time }
+    .label = Cydweddwyd diwethaf { $time }
+appmenu-fxa-sync-and-save-data2 = Cydweddu a chadw data
+appmenu-fxa-signed-in-label = Mewngofnodi
+appmenu-fxa-setup-sync =
+    .label = Cychwyn Cydweddu…
+appmenuitem-save-page =
+    .label = Cadw Tudalen Fel…
+
+## What's New panel in App menu.
+
+whatsnew-panel-header = Beth sy'n Newydd
+# Checkbox displayed at the bottom of the What's New panel, allowing users to
+# enable/disable What's New notifications.
+whatsnew-panel-footer-checkbox =
+    .label = Hysbysu am nodweddion newydd
+    .accesskey = H
+
+## The Firefox Profiler – The popup is the UI to turn on the profiler, and record
+## performance profiles. To enable it go to profiler.firefox.com and click
+## "Enable Profiler Menu Button".
+
+profiler-popup-button-idle =
+    .label = Proffiliwr
+    .tooltiptext = Cofnodi proffil perfformiad
+profiler-popup-button-recording =
+    .label = Proffiliwr
+    .tooltiptext = Mae'r proffiliwr yn recordio proffil
+profiler-popup-button-capturing =
+    .label = Proffiliwr
+    .tooltiptext = Mae'r proffiliwr yn cipio proffil
+profiler-popup-title =
+    .value = { -profiler-brand-name }
+profiler-popup-header-text = { -profiler-brand-name }
+profiler-popup-reveal-description-button =
+    .aria-label = Dangos rhagor o wybodaeth
+profiler-popup-description-title =
+    .value = Cofnodi, dadansoddi, rhannu
+profiler-popup-description = Cydweithiwch ar faterion perfformiad trwy gyhoeddi proffiliau i'w rhannu â'ch tîm.
+profiler-popup-learn-more-button =
+    .label = Dysgu rhagor
+profiler-popup-settings =
+    .value = Gosod­iadau
+# This link takes the user to about:profiling, and is only visible with the Custom preset.
+profiler-popup-edit-settings-button =
+    .label = Golygu Gosodiadau...
+profiler-popup-recording-screen = Yn cofnodi…
+profiler-popup-start-recording-button =
+    .label = Cychwyn Cofnodi
+profiler-popup-discard-button =
+    .label = Dileu
+profiler-popup-capture-button =
+    .label = Cipio
+profiler-popup-start-shortcut =
+    { PLATFORM() ->
+        [macos] ⌃⇧1
+       *[other] Ctrl+Shift+1
+    }
+profiler-popup-capture-shortcut =
+    { PLATFORM() ->
+        [macos] ⌃⇧2
+       *[other] Ctrl+Shift+2
+    }
+
+## Profiler presets
+## They are shown in the popup's select box.
+
+
+# Presets and their l10n IDs are defined in the file
+# devtools/client/performance-new/popup/background.jsm.js
+# Please take care that the same values are also defined in devtools' perftools.ftl.
+
+profiler-popup-presets-web-developer-description = Y rhagosodiad sy'n cael ei argymell ar gyfer y rhan fwyaf o ddadfygio apiau gwe, gyda gorbenion isel.
+profiler-popup-presets-web-developer-label =
+    .label = Datblygwr Gwe
+profiler-popup-presets-firefox-description = Rhagosodiad a argymhellir ar gyfer proffilio { -brand-shorter-name }.
+profiler-popup-presets-firefox-label =
+    .label = { -brand-shorter-name }
+profiler-popup-presets-graphics-description = Y rhagosodiad ar gyfer ymchwilio i wallau graffeg yn { -brand-shorter-name }.
+profiler-popup-presets-graphics-label =
+    .label = Graffigau
+profiler-popup-presets-media-description2 = Y rhagosodiad ar gyfer ymchwilio i wallau sain a fideo yn { -brand-shorter-name }.
+profiler-popup-presets-media-label =
+    .label = Cyfryngau
+profiler-popup-presets-networking-description = Y rhagosodiad ar gyfer ymchwilio i wallau graffeg yn { -brand-shorter-name }
+profiler-popup-presets-networking-label =
+    .label = Rhwydweithio
+profiler-popup-presets-power-description = Y rhagosodiad ar gyfer ymchwilio i wallau defnydd pŵer yn { -brand-shorter-name }, gyda gorbenion isel.
+# "Power" is used in the sense of energy (electricity used by the computer).
+profiler-popup-presets-power-label =
+    .label = Pŵer
+profiler-popup-presets-custom-label =
+    .label = Cyfaddas
+
+## History panel
+
+appmenu-manage-history =
+    .label = Rheoli Hanes
+appmenu-reopen-all-tabs = Ailagor Pob Tab
+appmenu-reopen-all-windows = Ailagor Pob Ffenestr
+appmenu-restore-session =
+    .label = Adfer y Sesiwn Flaenorol
+appmenu-clear-history =
+    .label = Clirio Hanes Diweddar…
+appmenu-recent-history-subheader = Hanes Diweddar
+appmenu-recently-closed-tabs =
+    .label = Tabiau Wedi eu Cau'n Ddiweddar
+appmenu-recently-closed-windows =
+    .label = Ffenestri wedi eu Cau yn Ddiweddar
+
+## Help panel
+
+appmenu-help-header =
+    .title = Cymorth { -brand-shorter-name }
+appmenu-about =
+    .label = Ynghylch { -brand-shorter-name }
+    .accesskey = n
+appmenu-get-help =
+    .label = Derbyn Cymorth
+    .accesskey = D
+appmenu-help-more-troubleshooting-info =
+    .label = Rhagor o Wybodaeth Datrys Problemau
+    .accesskey = D
+appmenu-help-report-site-issue =
+    .label = Adrodd ar Fater Gwefan…
+appmenu-help-share-ideas =
+    .label = Rhannwch syniadau ac adborth…
+    .accesskey = R
+
+## appmenu-help-enter-troubleshoot-mode and appmenu-help-exit-troubleshoot-mode
+## are mutually exclusive, so it's possible to use the same accesskey for both.
+
+appmenu-help-enter-troubleshoot-mode2 =
+    .label = Y Modd Datrys Problemau…
+    .accesskey = M
+appmenu-help-exit-troubleshoot-mode =
+    .label = Diffodd y Modd Dartrys Problemau
+    .accesskey = D
+
+## appmenu-help-report-deceptive-site and appmenu-help-not-deceptive
+## are mutually exclusive, so it's possible to use the same accesskey for both.
+
+appmenu-help-report-deceptive-site =
+    .label = Adroddwch ar wefan twyllodrus…
+    .accesskey = t
+appmenu-help-not-deceptive =
+    .label = Nid yw hon yn wefan twyllodrus…
+    .accesskey = t
+
+## More Tools
+
+appmenu-customizetoolbar =
+    .label = Cyfaddasu'r Bar Offer…
+appmenu-developer-tools-subheader = Offer y Porwr
+appmenu-developer-tools-extensions =
+    .label = Estyniadau ar gyfer Datblygwyr
diff --git a/l10n-cy/browser/browser/branding/brandings.ftl b/l10n-cy/browser/browser/branding/brandings.ftl
new file mode 100644
index 0000000000..cb38de2c50
--- /dev/null
+++ b/l10n-cy/browser/browser/branding/brandings.ftl
@@ -0,0 +1,46 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+## The following feature names must be treated as a brand.
+##
+## They cannot be:
+## - Transliterated.
+## - Translated.
+##
+## Declension should be avoided where possible, leaving the original
+## brand unaltered in prominent UI positions.
+##
+## For further details, consult:
+## https://mozilla-l10n.github.io/styleguides/mozilla_general/#brands-copyright-and-trademark
+
+-facebook-container-brand-name = Facebook Container
+-lockwise-brand-name = Firefox Lockwise
+-lockwise-brand-short-name = Lockwise
+-monitor-brand-name = Firefox Monitor
+-monitor-brand-short-name = Monitor
+-pocket-brand-name = Pocket
+-send-brand-name = Firefox Send
+-screenshots-brand-name = Firefox Screenshots
+-mozilla-vpn-brand-name = Mozilla VPN
+-profiler-brand-name = Firefox Profiler
+-translations-brand-name = Firefox Translations
+-rally-brand-name = Mozilla Rally
+-rally-short-name = Rally
+-focus-brand-name = Firefox Focus
+
+# “Suggest” can be localized, “Firefox” must be treated as a brand
+# and kept in English.
+-firefox-suggest-brand-name = Awgrymadau Firefox
+
+# ”Home" can be localized, “Firefox” must be treated as a brand
+# and kept in English.
+-firefox-home-brand-name = Cartref Firefox
+
+# View" can be localized, “Firefox” must be treated as a brand
+# and kept in English.
+-firefoxview-brand-name = Golwg Firefox
+
+-relay-brand-name = Firefox Relay
+-relay-brand-short-name = Relay
diff --git a/l10n-cy/browser/browser/branding/sync-brand.ftl b/l10n-cy/browser/browser/branding/sync-brand.ftl
new file mode 100644
index 0000000000..1dc6d58608
--- /dev/null
+++ b/l10n-cy/browser/browser/branding/sync-brand.ftl
@@ -0,0 +1,7 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# “Account” can be localized, “Firefox” must be treated as a brand,
+# and kept in English.
+-fxaccount-brand-name = Cyfrif Firefox
diff --git a/l10n-cy/browser/browser/browser.ftl b/l10n-cy/browser/browser/browser.ftl
new file mode 100644
index 0000000000..7f21a4d24f
--- /dev/null
+++ b/l10n-cy/browser/browser/browser.ftl
@@ -0,0 +1,983 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+## The main browser window's title
+
+# These are the default window titles everywhere except macOS. The first two
+# attributes are used when the web content opened has no title:
+#
+# default - "Mozilla Firefox"
+# private - "Mozilla Firefox (Private Browsing)"
+#
+# The last two are for use when there *is* a content title.
+# Variables:
+#  $content-title (String): the title of the web content.
+browser-main-window =
+    .data-title-default = { -brand-full-name }
+    .data-title-private = { -brand-full-name } (Pori Preifat)
+    .data-content-title-default = { $content-title } - { -brand-full-name }
+    .data-content-title-private = { $content-title } - { -brand-full-name } (Pori Preifat)
+# These are the default window titles on macOS. The first two are for use when
+# there is no content title:
+#
+# "default" - "Mozilla Firefox"
+# "private" - "Mozilla Firefox — (Private Browsing)"
+#
+# The last two are for use when there *is* a content title.
+# Do not use the brand name in the last two attributes, as we do on non-macOS.
+#
+# Also note the other subtle difference here: we use a `-` to separate the
+# brand name from `(Private Browsing)`, which does not happen on other OSes.
+#
+# Variables:
+#  $content-title (String): the title of the web content.
+browser-main-window-mac =
+    .data-title-default = { -brand-full-name }
+    .data-title-private = { -brand-full-name } - (Pori Preifat)
+    .data-content-title-default = { $content-title }
+    .data-content-title-private = { $content-title } - (Pori Preifat)
+# These are the default window titles everywhere except macOS. The first two
+# attributes are used when the web content opened has no title:
+#
+# default - "Mozilla Firefox"
+# private - "Mozilla Firefox (Private Browsing)"
+#
+# The last two are for use when there *is* a content title.
+# Variables:
+#  $content-title (String): the title of the web content.
+browser-main-window-window-titles =
+    .data-title-default = { -brand-full-name }
+    .data-title-private = { -brand-full-name } Pori Preifat
+    .data-content-title-default = { $content-title } — { -brand-full-name }
+    .data-content-title-private = { $content-title } — { -brand-full-name } Pori Preifat
+# These are the default window titles on macOS. The first two are for use when
+# there is no content title:
+#
+# "default" - "Mozilla Firefox"
+# "private" - "Mozilla Firefox — (Private Browsing)"
+#
+# The last two are for use when there *is* a content title.
+# Do not use the brand name in the last two attributes, as we do on non-macOS.
+#
+# Also note the other subtle difference here: we use a `-` to separate the
+# brand name from `(Private Browsing)`, which does not happen on other OSes.
+#
+# Variables:
+#  $content-title (String): the title of the web content.
+browser-main-window-mac-window-titles =
+    .data-title-default = { -brand-full-name }
+    .data-title-private = { -brand-full-name } — Pori Preifat
+    .data-content-title-default = { $content-title }
+    .data-content-title-private = { $content-title } — Pori Preifat
+# This gets set as the initial title, and is overridden as soon as we start
+# updating the titlebar based on loaded tabs or private browsing state.
+# This should match the `data-title-default` attribute in both
+# `browser-main-window` and `browser-main-window-mac`.
+browser-main-window-title = { -brand-full-name }
+# The non-variable portion of this MUST match the translation of
+# "PRIVATE_BROWSING_SHORTCUT_TITLE" in custom.properties
+private-browsing-shortcut-text-2 = Pori Preifat { -brand-shortcut-name }
+
+##
+
+urlbar-identity-button =
+    .aria-label = Gweld manylion y wefan
+
+## Tooltips for images appearing in the address bar
+
+urlbar-services-notification-anchor =
+    .tooltiptext = Agor panel y neges gosod
+urlbar-web-notification-anchor =
+    .tooltiptext = Newid p'un ai rydych yn derbyn hysbysiadau o'r wefan
+urlbar-midi-notification-anchor =
+    .tooltiptext = Agor panel MIDI
+urlbar-eme-notification-anchor =
+    .tooltiptext = Rheoli'r defnydd o feddalwedd DRM
+urlbar-web-authn-anchor =
+    .tooltiptext = Agor panel Dilysu Gwe
+urlbar-canvas-notification-anchor =
+    .tooltiptext = Rheoli caniatâd tynnu canfas
+urlbar-web-rtc-share-microphone-notification-anchor =
+    .tooltiptext = Rheoli rhannu eich meicroffon gyda'r wefan
+urlbar-default-notification-anchor =
+    .tooltiptext = Agor y panel negesu
+urlbar-geolocation-notification-anchor =
+    .tooltiptext = Agor panel cais y lleoliad
+urlbar-xr-notification-anchor =
+    .tooltiptext = Agor panel caniatâd rhithrealaeth
+urlbar-storage-access-anchor =
+    .tooltiptext = Agor panel caniatâd gweithgaredd pori
+urlbar-translate-notification-anchor =
+    .tooltiptext = Cyfieithu'r dudalen hon
+urlbar-web-rtc-share-screen-notification-anchor =
+    .tooltiptext = Rheoli rhannu eich ffenestri neu sgrin gyda'r wefan
+urlbar-indexed-db-notification-anchor =
+    .tooltiptext = Agor y panel neges storio all-lein
+urlbar-password-notification-anchor =
+    .tooltiptext = Agor panel neges y cyfrinair cadw
+urlbar-translated-notification-anchor =
+    .tooltiptext = Rheoli cyfieithu tudalennau
+urlbar-plugins-notification-anchor =
+    .tooltiptext = Rheoli defnydd ategion
+urlbar-web-rtc-share-devices-notification-anchor =
+    .tooltiptext = Rheoli rhannu eich camera a/neu feicroffon gyda'r wefan
+# "Speakers" is used in a general sense that might include headphones or
+# another audio output connection.
+urlbar-web-rtc-share-speaker-notification-anchor =
+    .tooltiptext = Rheoli rhannu eich seinyddion gyda'r wefan
+urlbar-autoplay-notification-anchor =
+    .tooltiptext = Agor panel awtochwarae
+urlbar-persistent-storage-notification-anchor =
+    .tooltiptext = Cadw data mewn Storfa Barhaus
+urlbar-addons-notification-anchor =
+    .tooltiptext = Agor panel neges gosod yr ychwanegyn
+urlbar-tip-help-icon =
+    .title = Derbyn cymorth
+urlbar-search-tips-confirm = Iawn, rwy'n deall
+urlbar-search-tips-confirm-short = Iawn
+# Read out before Urlbar Tip text content so screenreader users know the
+# subsequent text is a tip offered by the browser. It should end in a colon or
+# localized equivalent.
+urlbar-tip-icon-description =
+    .alt = Awgrym:
+urlbar-result-menu-button =
+    .title = Agor y ddewislen
+urlbar-result-menu-remove-from-history =
+    .label = Tynnu o'r hanes
+    .accesskey = T
+urlbar-result-menu-tip-get-help =
+    .label = Derbyn cymorth
+    .accesskey = D
+
+## Prompts users to use the Urlbar when they open a new tab or visit the
+## homepage of their default search engine.
+## Variables:
+##  $engineName (String): The name of the user's default search engine. e.g. "Google" or "DuckDuckGo".
+
+urlbar-search-tips-onboard = Teipio llai, canfod mwy: Chwiliwch gyda { $engineName } yn syth o'ch bar cyfeiriad.
+urlbar-search-tips-redirect-2 = Cychwynnwch eich chwilio yma i weld awgrymiadau gan { $engineName } a'ch hanes pori.
+# Make sure to match the name of the Search panel in settings.
+urlbar-search-tips-persist = Daeth chwilio yn lawer symlach. Ceisiwch wneud eich chwilio'n fwy penodol yma yn y bar cyfeiriad. I ddangos yr URL yn lle hynny, ewch i Chwilio, yn y Gosodiadau.
+# Prompts users to use the Urlbar when they are typing in the domain of a
+# search engine, e.g. google.com or amazon.com.
+urlbar-tabtosearch-onboard = Dewiswch y llwybr byr hwn i ddod o hyd i'r hyn sydd ei angen arnoch yn gynt.
+
+## Local search mode indicator labels in the urlbar
+
+urlbar-search-mode-bookmarks = Nodau tudalen
+urlbar-search-mode-tabs = Tabiau
+urlbar-search-mode-history = Hanes
+urlbar-search-mode-actions = Gweithredoedd
+
+##
+
+urlbar-geolocation-blocked =
+    .tooltiptext = Rydych wedi rhwystro'r manylion lleoliad ar gyfer y wefan hon.
+urlbar-xr-blocked =
+    .tooltiptext = Rydych wedi rhwystro mynediad dyfais rhithrealaeth ar gyfer y wefan hon.
+urlbar-web-notifications-blocked =
+    .tooltiptext = Rydych wedi rhwystro hysbysiadau ar gyfer y wefan hon.
+urlbar-camera-blocked =
+    .tooltiptext = Rydych wedi diffodd eich camera ar gyfer y wefan hon.
+urlbar-microphone-blocked =
+    .tooltiptext = Rydych wedi diffodd eich meicroffon ar gyfer y wefan hon.
+urlbar-screen-blocked =
+    .tooltiptext = Rydych wedi rhwystro'r wefan rhag rhannu eich sgrin.
+urlbar-persistent-storage-blocked =
+    .tooltiptext = Rydych wedi rhwystro storio data parhaus ar gyfer y wefan hon.
+urlbar-popup-blocked =
+    .tooltiptext = Rydych wedi rhwystro llamlenni ar gyfer y wefan hon.
+urlbar-autoplay-media-blocked =
+    .tooltiptext = Rydych wedi rhwystro cyfrwng awtochwarae gyda seiniau ar gyfer y wefan hon.
+urlbar-canvas-blocked =
+    .tooltiptext = Rydych wedi rhwystro tynnu data canvas o'r wefan hon.
+urlbar-midi-blocked =
+    .tooltiptext = Rydych wedi rhwystro mynediad MIDI ar gyfer y wefan hon.
+urlbar-install-blocked =
+    .tooltiptext = Rydych wedi rhwystro gosod ychwanegion ar gyfer y wefan hon.
+# Variables
+#   $shortcut (String) - A keyboard shortcut for the edit bookmark command.
+urlbar-star-edit-bookmark =
+    .tooltiptext = Golygu'r nod tudalen ({ $shortcut })
+# Variables
+#   $shortcut (String) - A keyboard shortcut for the add bookmark command.
+urlbar-star-add-bookmark =
+    .tooltiptext = Gosod nod tudalen i'r dudalen ({ $shortcut })
+
+## Page Action Context Menu
+
+page-action-manage-extension =
+    .label = Rheoli Estyniad…
+page-action-remove-extension =
+    .label = Tynnu Estyniad
+page-action-manage-extension2 =
+    .label = Rheoli Estyniad…
+    .accesskey = E
+page-action-remove-extension2 =
+    .label = Tynnu Estyniad
+    .accesskey = T
+
+## Auto-hide Context Menu
+
+full-screen-autohide =
+    .label = Cuddio Barrau Offer
+    .accesskey = u
+full-screen-exit =
+    .label = Gadael y Modd Sgrin Lawn
+    .accesskey = L
+
+## Search Engine selection buttons (one-offs)
+
+# This string prompts the user to use the list of search shortcuts in
+# the Urlbar and searchbar.
+search-one-offs-with-title = Y tro hwn, chwilio gyda:
+search-one-offs-change-settings-compact-button =
+    .tooltiptext = Newid y gosodiadau chwilio
+search-one-offs-context-open-new-tab =
+    .label = Chwilio mewn Tab Newydd
+    .accesskey = T
+search-one-offs-context-set-as-default =
+    .label = Gosod fel y Peiriant Chwilio Rhagosodedig
+    .accesskey = R
+search-one-offs-context-set-as-default-private =
+    .label = Gosod fel y Peiriant Chwilio Rhagosodedig ar gyfer Windows Preifat
+    .accesskey = G
+# Search engine one-off buttons with an @alias shortcut/keyword.
+# Variables:
+#  $engineName (String): The name of the engine.
+#  $alias (String): The @alias shortcut/keyword.
+search-one-offs-engine-with-alias =
+    .tooltiptext = { $engineName } ({ $alias })
+# Shown when adding new engines from the address bar shortcut buttons or context
+# menu, or from the search bar shortcut buttons.
+# Variables:
+#  $engineName (String): The name of the engine.
+search-one-offs-add-engine =
+    .label = Ychwanegu “{ $engineName }”
+    .tooltiptext = Ychwanegwch beiriant chwilio “{ $engineName }”
+    .aria-label = Ychwanegwch beiriant chwilio “{ $engineName }”
+# When more than 5 engines are offered by a web page, they are grouped in a
+# submenu using this as its label.
+search-one-offs-add-engine-menu =
+    .label = Ychwanegu peiriant chwilio
+
+## Local search mode one-off buttons
+## Variables:
+##  $restrict (String): The restriction token corresponding to the search mode.
+##    Restriction tokens are special characters users can type in the urlbar to
+##    restrict their searches to certain sources (e.g., "*" to search only
+##    bookmarks).
+
+search-one-offs-bookmarks =
+    .tooltiptext = Nodau tudalen ({ $restrict })
+search-one-offs-tabs =
+    .tooltiptext = Tabiau ({ $restrict })
+search-one-offs-history =
+    .tooltiptext = Hanes ({ $restrict })
+search-one-offs-actions =
+    .tooltiptext = Gweithredoedd ( { $restrict } )
+
+## QuickActions are shown in the urlbar as the user types a matching string
+## The -cmd- strings are comma separated list of keywords that will match
+## the action.
+
+# Opens the about:addons page in the home / recommendations section
+quickactions-addons = Gweld Ychwanegion
+quickactions-cmd-addons2 = ychwanegion
+# Opens the bookmarks library window
+quickactions-bookmarks2 = Rheoli nodau tudalen
+quickactions-cmd-bookmarks = nodau tudalen
+# Opens a SUMO article explaining how to clear history
+quickactions-clearhistory = Clirio Hanes
+quickactions-cmd-clearhistory = clirio hanes
+# Opens about:downloads page
+quickactions-downloads2 = Gweld llwythi
+quickactions-cmd-downloads = llwythi
+# Opens about:addons page in the extensions section
+quickactions-extensions = Rheoli estyniadau
+quickactions-cmd-extensions = estyniadau
+# Opens the devtools web inspector
+quickactions-inspector2 = Agor Offer Datblygwyr
+quickactions-cmd-inspector = arolygydd, devtools
+# Opens about:logins
+quickactions-logins2 = Rheoli cyfrineiriau
+quickactions-cmd-logins = mewngofnodion, cyfrineiriau
+# Opens about:addons page in the plugins section
+quickactions-plugins = Rheoli ategion
+quickactions-cmd-plugins = ategion
+# Opens the print dialog
+quickactions-print2 = Argraffu tudalen
+quickactions-cmd-print = argraffu
+# Opens a new private browsing window
+quickactions-private2 = Agor ffenestr breifat
+quickactions-cmd-private = pori preifat
+# Opens a SUMO article explaining how to refresh
+quickactions-refresh = Adnewyddu { -brand-short-name }
+quickactions-cmd-refresh = adnewyddu
+# Restarts the browser
+quickactions-restart = Ailgychwyn { -brand-short-name }
+quickactions-cmd-restart = ailgychwyn
+# Opens the screenshot tool
+quickactions-screenshot3 = Cymryd llun sgrin
+quickactions-cmd-screenshot = llun sgrin
+# Opens about:preferences
+quickactions-settings2 = Rheoli gosodiadau
+quickactions-cmd-settings = gosodiadau, dewisiadau, opsiynau
+# Opens about:addons page in the themes section
+quickactions-themes = Rheoli themâu
+quickactions-cmd-themes = themâu
+# Opens a SUMO article explaining how to update the browser
+quickactions-update = Diweddaru { -brand-short-name }
+quickactions-cmd-update = diweddaru
+# Opens the view-source UI with current pages source
+quickactions-viewsource2 = Gweld Ffynhonnell Tudalen
+quickactions-cmd-viewsource = gweld ffynhonnell, ffynhonnell
+# Tooltip text for the help button shown in the result.
+quickactions-learn-more =
+    .title = Dysgu rhagor am weithredoedd Cyflym
+
+## Bookmark Panel
+
+bookmarks-add-bookmark = Ychwanegu Nod Tudalen
+bookmarks-edit-bookmark = Golygu Nod Tudalen
+bookmark-panel-cancel =
+    .label = Diddymu
+    .accesskey = D
+# Variables:
+#  $count (number): number of bookmarks that will be removed
+bookmark-panel-remove =
+    .label =
+        { $count ->
+            [zero] Dileu dim Nodau Tudalen
+            [one] Dileu { $count } Nod Tudalen
+            [two] Dileu { $count } Nod Tudalen
+            [few] Dileu { $count } Nod Tudalen
+            [many] Dileu { $count } Nod Tudalen
+           *[other] Dileu { $count } Nod Tudalen
+        }
+    .accesskey = T
+bookmark-panel-show-editor-checkbox =
+    .label = Dangos y golygydd wrth gadw
+    .accesskey = D
+bookmark-panel-save-button =
+    .label = Cadw
+# Width of the bookmark panel.
+# Should be large enough to fully display the Done and
+# Cancel/Remove Bookmark buttons.
+bookmark-panel =
+    .style = min-width: 23em
+
+## Identity Panel
+
+# Variables
+#  $host (String): the hostname of the site that is being displayed.
+identity-site-information = Manylion gwefan { $host }
+# Variables
+#  $host (String): the hostname of the site that is being displayed.
+identity-header-security-with-host =
+    .title = Diogelwch Cysylltiad { $host }
+identity-connection-not-secure = Cysylltiad yn anniogel
+identity-connection-secure = Cysylltiad yn ddiogel
+identity-connection-failure = Methiant cysylltiad
+identity-connection-internal = Mae hon yn dudalen { -brand-short-name } diogel.
+identity-connection-file = Mae'r dudalen hon wedi ei chadw ar eich cyfrifiadur.
+identity-extension-page = Mae'r dudalen wedi ei llwytho o estyniad.
+identity-active-blocked = Mae { -brand-short-name } wedi rhwystro rhannau o'r dudalen nad ydynt yn ddiogel.
+identity-custom-root = Dilyswyd y cysylltiad gan gyhoeddwr tystysgrif nad yw'n cael ei gydnabod gan Mozilla.
+identity-passive-loaded = Nid yw rhannau o'r dudalen hon yn ddiogel (megis delweddau).
+identity-active-loaded = Rydych wedi analluogi diogelwch ar y dudalen hon.
+identity-weak-encryption = Mae'r dudalen hon yn defnyddio amgryptiad gwan.
+identity-insecure-login-forms = Gall mewngofnodion sy'n cael eu cyflwyno ar y dudalen hon gael eu cyfaddawdu.
+identity-https-only-connection-upgraded = (wedi'i uwchraddio i HTTPS)
+identity-https-only-label = Modd HTTPS-yn-Unig
+identity-https-only-dropdown-on =
+    .label = Ymlaen
+identity-https-only-dropdown-off =
+    .label = Diffodd
+identity-https-only-dropdown-off-temporarily =
+    .label = Diffodd dros dro
+identity-https-only-info-turn-on2 = Trowch y Modd HTTPS-yn-Unig ymlaen os ydych chi am i { -brand-short-name } uwchraddio'r cysylltiad lle'n bosibl.
+identity-https-only-info-turn-off2 = Os yw'r wefan yn ymddangos wedi torri, efallai yr hoffech chi ddiffodd Modd HTTPS-yn-Unig i'w ail-lwytho gan ddefnyddio HTTP anniogel.
+identity-https-only-info-no-upgrade = Methu uwchraddio'r cysylltiad o HTTP.
+identity-permissions-storage-access-header = Cwcis traws-gwefan
+identity-permissions-storage-access-hint = Gall y partïon hyn ddefnyddio cwcis traws-gwefan a data gwefan tra'ch bod chi ar y wefan hon.
+identity-permissions-storage-access-learn-more = Dysgu rhagor
+identity-permissions-reload-hint = Efallai y bydd angen ail lwytho'r dudalen i newidiadau ddod ar waith.
+identity-clear-site-data =
+    .label = Clirio Data Cwcis a Gwefan…
+identity-connection-not-secure-security-view = Nid ydych wedi'ch cysylltu'n ddiogel â'r wefan hon.
+identity-connection-verified = Rydych wedi eich cysylltu'n ddiogel â'r wefan hon.
+identity-ev-owner-label = Tystysgrif wedi'i ryddhau i:
+identity-description-custom-root = Nid yw Mozilla yn cydnabod y cyhoeddwr tystysgrif hwn. Efallai ei fod wedi'i ychwanegu o'ch system weithredu neu gan weinyddwr. <label data-l10n-name="link">Dysgu Rhagor</label>
+identity-remove-cert-exception =
+    .label = Tynnu Eithriad
+    .accesskey = E
+identity-description-insecure = Nid yw eich cysylltiad â'r dudalen hon yn breifat. Gall gwybodaeth fyddwch yn ei gyflwyno cael ei weld gan eraill (megis cyfrineiriau, negeseuon, cardiau credyd, ac ati.).
+identity-description-insecure-login-forms = Nid yw'r manylion mewngofnodi rydych wedi ei roi i'r dudalen yn ddiogel a gall fod wedi ei danseilio.
+identity-description-weak-cipher-intro = Mae eich cysylltiad i'r wefan hon yn defnyddio amgryptiad gwan ac nid yw'n breifat.
+identity-description-weak-cipher-risk = Gall bobl eraill weld eich manylion neu newid ymddygiad y wefan.
+identity-description-active-blocked = Mae { -brand-short-name } wedi rhwystro rhannau o'r dudalen nad ydynt yn ddiogel. <label data-l10n-name="link">Dysgu Rhagor</label>
+identity-description-passive-loaded = Nid yw eich cysylltiad yn breifat ac mae'n bosib i wybodaeth rydych yn ei rannu gael ei weld gan eraill.
+identity-description-passive-loaded-insecure = Mae'r wefan yn cynnwys deunydd nad yw'n ddiogel (megis delweddau). <label data-l10n-name="link">Dysgu Rhagor</label>
+identity-description-passive-loaded-mixed = Er bod { -brand-short-name } wedi rhwystro peth cynnwys, mae cynnwys dal ar y dudalen nad yw'n ddiogel (megis delweddau). <label data-l10n-name="link">Dysgu Rhagor</label>
+identity-description-active-loaded = Mae'r wefan yn cynnwys yn deunydd nad yw'n ddiogel (megis sgriptiau) ac nid yw eich cysylltiad â nhw'n breifat.
+identity-description-active-loaded-insecure = Gall gwybodaeth fyddwch yn ei gyflwyno cael ei weld gan eraill (megis cyfrineiriau, negeseuon, cardiau credyd, ac ati.).
+identity-learn-more =
+    .value = Dysgu Rhagor
+identity-disable-mixed-content-blocking =
+    .label = Analluogi diogelu dros dro
+    .accesskey = A
+identity-enable-mixed-content-blocking =
+    .label = Galluogi diogelu
+    .accesskey = G
+identity-more-info-link-text =
+    .label = Rhagor o Wybodaeth
+
+## Window controls
+
+browser-window-minimize-button =
+    .tooltiptext = Lleihau
+browser-window-maximize-button =
+    .tooltiptext = Mwyhau
+browser-window-restore-down-button =
+    .tooltiptext = Adfer i Lawr
+browser-window-close-button =
+    .tooltiptext = Cau
+
+## Tab actions
+
+# This label should be written in all capital letters if your locale supports them.
+browser-tab-audio-playing2 = YN CHWARAE
+# This label should be written in all capital letters if your locale supports them.
+browser-tab-audio-muted2 = WEDI TEWI
+# This label should be written in all capital letters if your locale supports them.
+browser-tab-audio-blocked = AWTOCHWARAE WEDI'I RWYSTRO
+# This label should be written in all capital letters if your locale supports them.
+browser-tab-audio-pip = LLUN-MEWN-LLUN
+
+## These labels should be written in all capital letters if your locale supports them.
+## Variables:
+##  $count (number): number of affected tabs
+
+browser-tab-mute =
+    { $count ->
+        [1] MUDO TAB
+        [zero] MUDO { $count } TABIAU
+        [one] MUDO { $count } TAB
+        [two] MUDO { $count } DAB
+        [few] MUDO { $count } THAB
+        [many] MUDO { $count } THAB
+       *[other] MUDO { $count } TAB
+    }
+browser-tab-unmute =
+    { $count ->
+        [1] DAD-FUDO TAB
+        [zero] DAD-FUDO { $count } TABIAU
+        [one] DAD-FUDO { $count } TAB
+        [two] DAD-FUDO { $count } DAB
+        [few] DAD-FUDO { $count } THAB
+        [many] DAD-FUDO { $count } THAB
+       *[other] DAD-FUDO { $count } TAB
+    }
+browser-tab-unblock =
+    { $count ->
+        [1] CHWARAE TAB
+        [zero] CHWARAE TABIAU
+        [one] CHWARAE { $count } TAB
+        [two] CHWARAE { $count } DAB
+        [few] CHWARAE { $count } THAB
+        [many] CHWARAE { $count } THAB
+       *[other] CHWARAE { $count } TAB
+    }
+
+## Bookmarks toolbar items
+
+browser-import-button2 =
+    .label = Mewnforio nodau tudalen…
+    .tooltiptext = Mewnforio nodau tudalen o borwr arall i { -brand-short-name }.
+bookmarks-toolbar-empty-message = I gael mynediad cyflym, rhowch eich nodau tudalen yma ar y bar offer nodau tudalen. <a data-l10n-name="manage-bookmarks"> Rheoli nodau tudalen…</a>
+
+## WebRTC Pop-up notifications
+
+popup-select-camera-device =
+    .value = Camera:
+    .accesskey = C
+popup-select-camera-icon =
+    .tooltiptext = Camera
+popup-select-microphone-device =
+    .value = Meicroffon:
+    .accesskey = M
+popup-select-microphone-icon =
+    .tooltiptext = Meicroffon
+popup-select-speaker-icon =
+    .tooltiptext = Seinyddion
+popup-select-window-or-screen =
+    .label = Ffenestr neu sgrin:
+    .accesskey = F
+popup-all-windows-shared = Bydd pob ffenestr gweladwy ar eich sgrin yn cael eu rhannu.
+popup-screen-sharing-block =
+    .label = Rhwystro
+    .accesskey = R
+popup-screen-sharing-always-block =
+    .label = Rhwystro bob tro
+    .accesskey = b
+popup-mute-notifications-checkbox = Tewi hysbysiadau gwefan tra'n rhannu
+
+## WebRTC window or screen share tab switch warning
+
+sharing-warning-window = Rydych yn rhannu { -brand-short-name }. Gall pobl eraill weld pan fyddwch chi'n newid i dab newydd.
+sharing-warning-screen = Rydych chi'n rhannu'ch sgrin gyfan. Gall pobl eraill weld pan fyddwch chi'n newid i dab newydd.
+sharing-warning-proceed-to-tab =
+    .label = Ymlaen i Dab
+sharing-warning-disable-for-session =
+    .label = Analluogi diogelwch rhannu ar gyfer y sesiwn hon
+
+## DevTools F12 popup
+
+enable-devtools-popup-description = I ddefnyddio llwybr byr F12 agorwch DevTools yn gyntaf trwy'r ddewislen Datblygwr Gwe.
+enable-devtools-popup-description2 = I ddefnyddio'r llwybr byr F12, agorwch DevTools yn gyntaf trwy'r ddewislen Offer Porwr.
+
+## URL Bar
+
+# This placeholder is used when not in search mode and the user's default search
+# engine is unknown.
+urlbar-placeholder =
+    .placeholder = Chwilio neu gyfeiriad gwe
+# This placeholder is used in search mode with search engines that search the
+# entire web.
+# Variables
+#  $name (String): the name of a search engine that searches the entire Web
+#  (e.g. Google).
+urlbar-placeholder-search-mode-web-2 =
+    .placeholder = Chwilio'r We
+    .aria-label = Chwilio gyda { $name }
+# This placeholder is used in search mode with search engines that search a
+# specific site (e.g., Amazon).
+# Variables
+#  $name (String): the name of a search engine that searches a specific site
+#  (e.g. Amazon).
+urlbar-placeholder-search-mode-other-engine =
+    .placeholder = Rhowch dermau chwilio
+    .aria-label = Chwilio { $name }
+# This placeholder is used when searching bookmarks.
+urlbar-placeholder-search-mode-other-bookmarks =
+    .placeholder = Rhowch dermau chwilio
+    .aria-label = Chwilio'r nodau tudalen
+# This placeholder is used when searching history.
+urlbar-placeholder-search-mode-other-history =
+    .placeholder = Rhowch dermau chwilio
+    .aria-label = Chwilio'ch hanes
+# This placeholder is used when searching open tabs.
+urlbar-placeholder-search-mode-other-tabs =
+    .placeholder = Rhowch dermau chwilio
+    .aria-label = Chwilio'r tabiau
+# This placeholder is used when searching quick actions.
+urlbar-placeholder-search-mode-other-actions =
+    .placeholder = Rhowch dermau chwilio
+    .aria-label = Gweithredoedd chwilio
+# Variables
+#  $name (String): the name of the user's default search engine
+urlbar-placeholder-with-name =
+    .placeholder = Chwilio gyda { $name } neu rhoi'r cyfeiriad
+# Variables
+#  $component (String): the name of the component which forces remote control.
+#    Example: "DevTools", "Marionette", "RemoteAgent".
+urlbar-remote-control-notification-anchor2 =
+    .tooltiptext = Mae'r porwr o dan reolaeth bell (rheswm: { $component })
+urlbar-permissions-granted =
+    .tooltiptext = Rydych wedi rhoi caniatâd ychwanegol i'r wefan hon.
+urlbar-switch-to-tab =
+    .value = Newid i dab:
+# Used to indicate that a selected autocomplete entry is provided by an extension.
+urlbar-extension =
+    .value = Estyniad:
+urlbar-go-button =
+    .tooltiptext = Mynd i'r cyfeiriad yn y Bar Lleoliad
+urlbar-page-action-button =
+    .tooltiptext = Gweithredoedd tudalen
+
+## Action text shown in urlbar results, usually appended after the search
+## string or the url, like "result value - action text".
+
+# Used when the private browsing engine differs from the default engine.
+# The "with" format was chosen because the search engine name can end with
+# "Search", and we would like to avoid strings like "Search MSN Search".
+# Variables
+#  $engine (String): the name of a search engine
+urlbar-result-action-search-in-private-w-engine = Chwilio gyda { $engine } mewn Ffenestr Breifat
+# Used when the private browsing engine is the same as the default engine.
+urlbar-result-action-search-in-private = Chwilio mewn Ffenestr Breifat
+# The "with" format was chosen because the search engine name can end with
+# "Search", and we would like to avoid strings like "Search MSN Search".
+# Variables
+#  $engine (String): the name of a search engine
+urlbar-result-action-search-w-engine = Chwilio gyda { $engine }
+urlbar-result-action-sponsored = Noddwyd
+urlbar-result-action-switch-tab = Newid i'r Tab
+urlbar-result-action-visit = Ymweld â
+# Directs a user to press the Tab key to perform a search with the specified
+# engine.
+# Variables
+#  $engine (String): the name of a search engine that searches the entire Web
+#  (e.g. Google).
+urlbar-result-action-before-tabtosearch-web = Pwyswch Tab i chwilio gyda { $engine }
+# Directs a user to press the Tab key to perform a search with the specified
+# engine.
+# Variables
+#  $engine (String): the name of a search engine that searches a specific site
+#  (e.g. Amazon).
+urlbar-result-action-before-tabtosearch-other = Pwyswch Tab i chwilio { $engine }
+# Variables
+#  $engine (String): the name of a search engine that searches the entire Web
+#  (e.g. Google).
+urlbar-result-action-tabtosearch-web = Chwilio gyda { $engine } yn syth o'r bar cyfeiriad
+# Variables
+#  $engine (String): the name of a search engine that searches a specific site
+#  (e.g. Amazon).
+urlbar-result-action-tabtosearch-other-engine = Chwilio gyda { $engine } yn syth o'r bar cyfeiriad
+# Action text for copying to clipboard.
+urlbar-result-action-copy-to-clipboard = Copïo
+# Shows the result of a formula expression being calculated, the last = sign will be shown
+# as part of the result (e.g. "= 2").
+# Variables
+#  $result (String): the string representation for a formula result
+urlbar-result-action-calculator-result = = { $result }
+
+## Action text shown in urlbar results, usually appended after the search
+## string or the url, like "result value - action text".
+## In these actions "Search" is a verb, followed by where the search is performed.
+
+urlbar-result-action-search-bookmarks = Chwilio'r Nodau Tudalen
+urlbar-result-action-search-history = Chwilio'r Hanes
+urlbar-result-action-search-tabs = Chwilio'r Tabiau
+urlbar-result-action-search-actions = Gweithredoedd Chwilio
+
+## Labels shown above groups of urlbar results
+
+# A label shown above the "Firefox Suggest" (bookmarks/history) group in the
+# urlbar results.
+urlbar-group-firefox-suggest =
+    .label = { -firefox-suggest-brand-name }
+# A label shown above the search suggestions group in the urlbar results. It
+# should use sentence case.
+# Variables
+#  $engine (String): the name of the search engine providing the suggestions
+urlbar-group-search-suggestions =
+    .label = Awgrymiadau { $engine }
+# A label shown above Quick Actions in the urlbar results.
+urlbar-group-quickactions =
+    .label = Gweithredoedd Cyflym
+
+## Reader View toolbar buttons
+
+# This should match menu-view-enter-readerview in menubar.ftl
+reader-view-enter-button =
+    .aria-label = Mynd i'r Golwg Darllen
+# This should match menu-view-close-readerview in menubar.ftl
+reader-view-close-button =
+    .aria-label = Cau'r Golwg Darllen
+
+## Full Screen and Pointer Lock UI
+
+# Please ensure that the domain stays in the `<span data-l10n-name="domain">` markup.
+# Variables
+#  $domain (String): the domain that is full screen, e.g. "mozilla.org"
+fullscreen-warning-domain = <span data-l10n-name="domain">{ $domain }</span> nawr yn sgrin lawn
+fullscreen-warning-no-domain = Mae'r ddogfen nawr yn sgrin lawn
+fullscreen-exit-button = Gadael y Sgrin Lawn (Esc)
+# "esc" is lowercase on mac keyboards, but uppercase elsewhere.
+fullscreen-exit-mac-button = Gadael y Sgrin Lawn (esc)
+# Please ensure that the domain stays in the `<span data-l10n-name="domain">` markup.
+# Variables
+#  $domain (String): the domain that is using pointer-lock, e.g. "mozilla.org"
+pointerlock-warning-domain = <span data-l10n-name="domain">{ $domain }</span> reolaeth o'ch pwyntydd. Pwyswch Esc i adennill rheolaeth.
+pointerlock-warning-no-domain = Mae gan y ddogfen hon reolaeth o'ch pwyntydd. Pwyswch Esc i adennill rheolaeth.
+
+## Subframe crash notification
+
+crashed-subframe-message = <strong>Mae rhan o'r dudalen hon wedi chwalu.</strong> Er mwyn rhoi gwybod i { -brand-product-name } am y mater hwn a'i drwsio'n gynt, cyflwynwch adroddiad.
+# The string for crashed-subframe-title.title should match crashed-subframe-message,
+# but without any markup.
+crashed-subframe-title =
+    .title = <strong>Mae rhan o'r dudalen hon wedi chwalu.</strong> Er mwyn rhoi gwybod i { -brand-product-name } am y mater hwn a'i drwsio'n gynt, cyflwynwch adroddiad.
+crashed-subframe-learnmore-link =
+    .value = Dysgu Rhagor
+crashed-subframe-submit =
+    .label = Cyflwyno Adroddiad
+    .accesskey = A
+
+## Bookmarks panels, menus and toolbar
+
+bookmarks-manage-bookmarks =
+    .label = Rheoli Nodau Tudalen
+bookmarks-recent-bookmarks-panel-subheader = Nodau Tudalen Diweddar
+bookmarks-toolbar-chevron =
+    .tooltiptext = Dangos pob ffolder nod tudalen
+bookmarks-sidebar-content =
+    .aria-label = Nodau Tudalen
+bookmarks-menu-button =
+    .label = Dewislen Nodau Tudalen
+bookmarks-other-bookmarks-menu =
+    .label = Nodau Tudalen Eraill
+bookmarks-mobile-bookmarks-menu =
+    .label = Nodau Tudalen Symudol
+bookmarks-tools-sidebar-visibility =
+    .label =
+        { $isVisible ->
+            [true] Cuddio'r Bar Ochr Nodau Tudalen
+           *[other] Gweld Bar Offer Nodau Tudalen
+        }
+bookmarks-tools-toolbar-visibility-menuitem =
+    .label =
+        { $isVisible ->
+            [true] Cuddio'r Bar Offer Nodau Tudalen
+           *[other] Gweld Bar Offer Nodau Tudalen
+        }
+bookmarks-tools-toolbar-visibility-panel =
+    .label =
+        { $isVisible ->
+            [true] Cuddio'r Bar Offer Nodau Tudalen
+           *[other] Dangos y Bar Offer Nodau Tudalen
+        }
+bookmarks-tools-menu-button-visibility =
+    .label =
+        { $isVisible ->
+            [true] Tynnu Dewislen Nodau Tudalen o'r Bar Offer
+           *[other] Ychwanegu Dewislen Nodau Tudalen i'r Bar Offer
+        }
+bookmarks-search =
+    .label = Chwilio'r Nodau Tudalen
+bookmarks-tools =
+    .label = Offer Nodau Tudalen
+bookmarks-bookmark-edit-panel =
+    .label = Golygu'r Nod Tudalen
+bookmarks-subview-edit-bookmark =
+    .label = Golygu'r nod tudalen…
+# The aria-label is a spoken label that should not include the word "toolbar" or
+# such, because screen readers already know that this container is a toolbar.
+# This avoids double-speaking.
+bookmarks-toolbar =
+    .toolbarname = Bar Offer Nodau Tudalen
+    .accesskey = N
+    .aria-label = Nodau Tudalen
+bookmarks-toolbar-menu =
+    .label = Bar Offer Nodau Tudalen
+bookmarks-toolbar-placeholder =
+    .title = Eitemau Bar Offer Nodau Tudalen
+bookmarks-toolbar-placeholder-button =
+    .label = Eitemau Bar Offer Nodau Tudalen
+# "Bookmark" is a verb, as in "Add current tab to bookmarks".
+bookmarks-current-tab =
+    .label = Gosod Nod Tudalen i'r Tab Cyfredol
+# "Bookmark" is a verb, as in "Add current tab to bookmarks".
+bookmarks-subview-bookmark-tab =
+    .label = Gosod nod tudalen i'r tab cyfredol…
+
+## Library Panel items
+
+library-bookmarks-menu =
+    .label = Nodau Tudalen
+library-recent-activity-title =
+    .value = Gweithgareddau Diweddar
+
+## Pocket toolbar button
+
+save-to-pocket-button =
+    .label = Cadw i { -pocket-brand-name }
+    .tooltiptext = Cadw i { -pocket-brand-name }
+
+## Repair text encoding toolbar button
+
+repair-text-encoding-button =
+    .label = Trwsio amgodio testun
+    .tooltiptext = Dyfalu'r amgodio testun cywir o gynnwys y dudalen
+
+## Customize Toolbar Buttons
+
+# Variables:
+#  $shortcut (String): keyboard shortcut to open the add-ons manager
+toolbar-addons-themes-button =
+    .label = Ychwanegion a Themâu
+    .tooltiptext = Rheolwch eich ychwanegion a'ch thenâu ({ $shortcut })
+# Variables:
+#  $shortcut (String): keyboard shortcut to open settings (only on macOS)
+toolbar-settings-button =
+    .label = Gosodiadau
+    .tooltiptext =
+        { PLATFORM() ->
+            [macos] Agor y gosodiadau ({ $shortcut })
+           *[other] Agor y gosodiadau
+        }
+toolbar-overflow-customize-button =
+    .label = Cyfaddasu'r Bar Offer…
+    .accesskey = C
+toolbar-button-email-link =
+    .label = E-bostio'r Ddolen
+    .tooltiptext = E-bostio dolen i'r dudalen hon
+# Variables:
+#  $shortcut (String): keyboard shortcut to save a copy of the page
+toolbar-button-save-page =
+    .label = Cadw Tudalen
+    .tooltiptext = Cadw'r dudalen hon ({ $shortcut })
+# Variables:
+#  $shortcut (String): keyboard shortcut to open a local file
+toolbar-button-open-file =
+    .label = Agor Ffeil
+    .tooltiptext = Agor ffeil ({ $shortcut })
+toolbar-button-synced-tabs =
+    .label = Tabiau wedi'u Cydweddu
+    .tooltiptext = Dangos tabiau o ddyfeisiau eraill
+# Variables
+# $shortcut (string) - Keyboard shortcut to open a new private browsing window
+toolbar-button-new-private-window =
+    .label = Ffenestr Breifat Newydd
+    .tooltiptext = Agor ffenestr Pori Preifat newydd ({ $shortcut })
+
+## EME notification panel
+
+eme-notifications-drm-content-playing = Mae peth sain a fideo ar y wefan yn defnyddio meddalwedd DRM, gall gyfyngu'r hyn y gall { -brand-short-name } ei wneud gydag ef.
+eme-notifications-drm-content-playing-manage = Rheoli Gosodiadau
+eme-notifications-drm-content-playing-manage-accesskey = R
+eme-notifications-drm-content-playing-dismiss = Cau
+eme-notifications-drm-content-playing-dismiss-accesskey = C
+
+## Password save/update panel
+
+panel-save-update-username = Enw Defnyddiwr
+panel-save-update-password = Cyfrinair
+
+## Add-on removal warning
+
+# Variables:
+#  $name (String): The name of the addon that will be removed.
+addon-removal-title = Tynnu { $name }?
+addon-removal-abuse-report-checkbox = Adroddwch yr estyniad hwn i { -vendor-short-name }
+
+##
+
+# "More" item in macOS share menu
+menu-share-more =
+    .label = Rhagor…
+ui-tour-info-panel-close =
+    .tooltiptext = Cau
+
+## Variables:
+##  $uriHost (String): URI host for which the popup was allowed or blocked.
+
+popups-infobar-allow =
+    .label = Caniatáu llamlenni ar gyfer { $uriHost }
+    .accesskey = l
+popups-infobar-block =
+    .label = Rhwystro llamlenni ar gyfer { $uriHost }
+    .accesskey = l
+
+##
+
+popups-infobar-dont-show-message =
+    .label = Peidio dangos y neges pan mae llamlenni wedi eu rhwystro
+    .accesskey = P
+edit-popup-settings =
+    .label = Rheoli gosodiadau llamlenni…
+    .accesskey = l
+picture-in-picture-hide-toggle =
+    .label = Cuddio'r Togl Llun mewn Llun
+    .accesskey = L
+
+## Since the default position for PiP controls does not change for RTL layout,
+## right-to-left languages should use "Left" and "Right" as in the English strings,
+
+picture-in-picture-move-toggle-right =
+    .label = Symud Toglo Llun-mewn-Llun i'r Ochr Dde
+    .accesskey = D
+picture-in-picture-move-toggle-left =
+    .label = Symud Toglo Llun-mewn-Llun i'r Ochr Chwith
+    .accesskey = C
+
+##
+
+
+# Navigator Toolbox
+
+# This string is a spoken label that should not include
+# the word "toolbar" or such, because screen readers already know that
+# this container is a toolbar. This avoids double-speaking.
+navbar-accessible =
+    .aria-label = Llywio
+navbar-downloads =
+    .label = Llwytho i Lawr
+navbar-overflow =
+    .tooltiptext = Rhagor o offer…
+# Variables:
+#   $shortcut (String): keyboard shortcut to print the page
+navbar-print =
+    .label = Argraffu
+    .tooltiptext = Argraffu'r dudalen… ({ $shortcut })
+navbar-home =
+    .label = Cartref
+    .tooltiptext = Cartref { -brand-short-name }
+navbar-library =
+    .label = Llyfrgell
+    .tooltiptext = Gweld hanes, nodau tudalen wedi eu cadw, a rhagor
+navbar-search =
+    .title = Chwilio
+navbar-accessibility-indicator =
+    .tooltiptext = Nodweddion Hygyrchedd wedi eu Galluogi
+# Name for the tabs toolbar as spoken by screen readers. The word
+# "toolbar" is appended automatically and should not be included in
+# in the string
+tabs-toolbar =
+    .aria-label = Tabiau porwyr
+tabs-toolbar-new-tab =
+    .label = Tab Newydd
+tabs-toolbar-list-all-tabs =
+    .label = Rhestru pob tab
+    .tooltiptext = Rhestru pob tab
+
+## Infobar shown at startup to suggest session-restore
+
+# <img data-l10n-name="icon"/> will be replaced by the application menu icon
+restore-session-startup-suggestion-message = <strong>Eisiau agor tabiau blaenorol?</strong> Gallwch adfer eich sesiwn flaenorol o ddewislen ap { -brand-short-name } <img data-l10n-name = "icon" />, o dan Hanes.
+restore-session-startup-suggestion-button = Dangos sut mae gwneud
+
+## Mozilla data reporting notification (Telemetry, Firefox Health Report, etc)
+
+data-reporting-notification-message = Mae { -brand-short-name } yn anfon peth data yn awtomatig i { -vendor-short-name } fel bod modd i ni wella eich profiad.
+data-reporting-notification-button =
+    .label = Dewis Beth Rwy'n Rhannu
+    .accesskey = D
+# Label for the indicator shown in the private browsing window titlebar.
+private-browsing-indicator-label = Pori preifat
+
+## Unified extensions (toolbar) button
+
+unified-extensions-button =
+    .label = Estyniadau
+    .tooltiptext = Estyniadau
+
+## Unified extensions button when permission(s) are needed.
+## Note that the new line is intentionally part of the tooltip.
+
+unified-extensions-button-permissions-needed =
+    .label = Estyniadau
+    .tooltiptext =
+        Estyniadau
+        Angen caniatâd
+
+## Autorefresh blocker
+
+refresh-blocked-refresh-label = Rhwystrodd { -brand-short-name } y dudalen hon rhag ailagor yn awtomatig.
+refresh-blocked-redirect-label = Rhwystrodd { -brand-short-name } y dudalen hon rhag ailgyfeirio i dudalen arall.
+refresh-blocked-allow =
+    .label = Caniatáu
+    .accesskey = C
+
+## Firefox Relay integration
+
+firefox-relay-offer-why-relay = Mae { -relay-brand-name } yn cuddio'ch gwir gyfeiriad e-bost er mwyn helpu i'ch diogelu chi rhag tor-data a sbam.
+firefox-relay-offer-how-we-integrate = Trwy barhau, byddwch yn gallu cynhyrchu arallenwau e-bost { -relay-brand-short-name } newydd yn uniongyrchol o'ch rheolwr cyfrineiriau { -brand-shorter-name }.
+# Variables:
+#  $sitename (String): name of the site where user enters their Relay mask
+#  $useremail (String): user email that will receive messages
+firefox-relay-offer-what-relay-does = Byddwn yn anfon pob e-bost o <strong>{ $sitename }</strong> ymlaen at <strong>{ $useremail }</strong>.
diff --git a/l10n-cy/browser/browser/browserContext.ftl b/l10n-cy/browser/browser/browserContext.ftl
new file mode 100644
index 0000000000..2db65f4eef
--- /dev/null
+++ b/l10n-cy/browser/browser/browserContext.ftl
@@ -0,0 +1,514 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+navbar-tooltip-instruction =
+    .value =
+        { PLATFORM() ->
+            [macos] Tynnu lawr i ddangos hanes
+           *[other] Clic de neu dynnu lawr i ddangos hanes
+        }
+
+## Back
+
+# Variables
+#   $shortcut (String) - A keyboard shortcut for the Go Back command.
+main-context-menu-back-2 =
+    .tooltiptext = Nôl un tudalen ({ $shortcut })
+    .aria-label = Nôl
+    .accesskey = N
+
+# This menuitem is only visible on macOS
+main-context-menu-back-mac =
+    .label = Nôl
+    .accesskey = N
+
+navbar-tooltip-back-2 =
+    .value = { main-context-menu-back-2.tooltiptext }
+
+toolbar-button-back-2 =
+    .label = { main-context-menu-back-2.aria-label }
+
+## Forward
+
+# Variables
+#   $shortcut (String) - A keyboard shortcut for the Go Forward command.
+main-context-menu-forward-2 =
+    .tooltiptext = Ymlaen un tudalen ({ $shortcut })
+    .aria-label = Ymlaen
+    .accesskey = Y
+
+# This menuitem is only visible on macOS
+main-context-menu-forward-mac =
+    .label = Ymlaen
+    .accesskey = Y
+
+navbar-tooltip-forward-2 =
+    .value = { main-context-menu-forward-2.tooltiptext }
+
+toolbar-button-forward-2 =
+    .label = { main-context-menu-forward-2.aria-label }
+
+## Reload
+
+main-context-menu-reload =
+    .aria-label = Ail-lwytho
+    .accesskey = A
+
+# This menuitem is only visible on macOS
+main-context-menu-reload-mac =
+    .label = Ail-lwytho
+    .accesskey = A
+
+toolbar-button-reload =
+    .label = { main-context-menu-reload.aria-label }
+
+## Stop
+
+main-context-menu-stop =
+    .aria-label = Atal
+    .accesskey = t
+
+# This menuitem is only visible on macOS
+main-context-menu-stop-mac =
+    .label = Atal
+    .accesskey = t
+
+toolbar-button-stop =
+    .label = { main-context-menu-stop.aria-label }
+
+## Stop-Reload Button
+
+toolbar-button-stop-reload =
+    .title = { main-context-menu-reload.aria-label }
+
+## Firefox Account Button
+
+toolbar-button-fxaccount =
+    .label = { -fxaccount-brand-name }
+    .tooltiptext = { -fxaccount-brand-name }
+
+## Save Page
+
+main-context-menu-page-save =
+    .label = Cadw Tudalen Fel…
+    .accesskey = T
+
+## Simple menu items
+
+main-context-menu-bookmark-add =
+    .aria-label = Gosod Nod Tudalen i'r Dudalen
+    .accesskey = N
+    .tooltiptext = Gosod nod tudalen i'r dudalen
+
+# This menuitem is only visible on macOS
+# Cannot be shown at the same time as main-context-menu-bookmark-edit-mac,
+# so should probably have the same access key if possible.
+main-context-menu-bookmark-add-mac =
+    .label = Gosod Nod i Dudalen
+    .accesskey = N
+
+# This menuitem is only visible on macOS
+# Cannot be shown at the same time as main-context-menu-bookmark-add-mac,
+# so should probably have the same access key if possible.
+main-context-menu-bookmark-edit-mac =
+    .label = Golygu Nod Tudalen
+    .accesskey = G
+
+# Variables
+#   $shortcut (String) - A keyboard shortcut for the add bookmark command.
+main-context-menu-bookmark-add-with-shortcut =
+    .aria-label = Gosod Nod Tudalen i'r Dudalen
+    .accesskey = N
+    .tooltiptext = Gosod nod tudalen i'r dudalen ({ $shortcut })
+
+main-context-menu-bookmark-change =
+    .aria-label = Golygu'r Nod Tudalen
+    .accesskey = N
+    .tooltiptext = Golygu'r nod tudalen
+
+# Variables
+#   $shortcut (String) - A keyboard shortcut for the edit bookmark command.
+main-context-menu-bookmark-change-with-shortcut =
+    .aria-label = Golygu'r Nod Tudalen
+    .accesskey = N
+    .tooltiptext = Golygu'r nod tudalen ({ $shortcut })
+
+main-context-menu-bookmark-page =
+    .aria-label = Gosod Nod i Dudalen…
+    .accesskey = N
+    .tooltiptext = Gosod nod i dudalen
+
+# This menuitem is only visible on macOS
+# Cannot be shown at the same time as main-context-menu-edit-bookmark-mac,
+# so should probably have the same access key if possible.
+main-context-menu-bookmark-page-mac =
+    .label = Gosod Nod i Dudalen…
+    .accesskey = N
+
+# This menuitem is only visible on macOS
+# Cannot be shown at the same time as main-context-menu-bookmark-page-mac,
+# so should probably have the same access key if possible.
+main-context-menu-edit-bookmark-mac =
+    .label = Golygu Nod Tudalen…
+    .accesskey = G
+
+# Variables
+#   $shortcut (String) - A keyboard shortcut for the add bookmark command.
+main-context-menu-bookmark-page-with-shortcut =
+    .aria-label = Gosod Nod i Dudalen…
+    .accesskey = N
+    .tooltiptext = Gosod nod i dudalen ({ $shortcut })
+
+main-context-menu-edit-bookmark =
+    .aria-label = Golygu Nod Tudalen…
+    .accesskey = G
+    .tooltiptext = Golygu nod tudalen
+
+# Variables
+#   $shortcut (String) - A keyboard shortcut for the edit bookmark command.
+main-context-menu-edit-bookmark-with-shortcut =
+    .aria-label = Golygu Nod Tudalen…
+    .accesskey = G
+    .tooltiptext = Golygu nod tudalen ({ $shortcut })
+
+main-context-menu-open-link =
+    .label = Agor Dolen
+    .accesskey = D
+
+main-context-menu-open-link-new-tab =
+    .label = Agor Dolen mewn Tab Newydd
+    .accesskey = T
+
+main-context-menu-open-link-container-tab =
+    .label = Agor Dolen mewn Tab Cynhwysydd Newydd
+    .accesskey = T
+
+main-context-menu-open-link-new-window =
+    .label = Agor Dolen mewn Ffenestr Newydd
+    .accesskey = F
+
+main-context-menu-open-link-new-private-window =
+    .label = Agor Dolen mewn Ffenestr Breifat
+    .accesskey = F
+
+main-context-menu-bookmark-link =
+    .label = Dolen Nod Tudalen
+    .accesskey = D
+
+main-context-menu-bookmark-link-2 =
+    .label = Dolen Nod Tudalen
+    .accesskey = D
+
+main-context-menu-save-link =
+    .label = Cadw'r Ddolen Fel…
+    .accesskey = a
+
+main-context-menu-save-link-to-pocket =
+    .label = Cadw Dolen i { -pocket-brand-name }
+    .accesskey = o
+
+## The access keys for "Copy Link" and "Copy Email Address"
+## should be the same if possible; the two context menu items
+## are mutually exclusive.
+
+main-context-menu-copy-email =
+    .label = Copïo Cyfeiriad E-bost
+    .accesskey = E
+
+main-context-menu-copy-phone =
+    .label = Copïo Rhif Ffôn
+    .accesskey = C
+
+main-context-menu-copy-link-simple =
+    .label = Copïo'r Ddolen
+    .accesskey = C
+
+## Media (video/audio) controls
+##
+## The accesskey for "Play" and "Pause" are the
+## same because the two context-menu items are
+## mutually exclusive.
+
+main-context-menu-media-play =
+    .label = Chwarae
+    .accesskey = C
+
+main-context-menu-media-pause =
+    .label = Oedi
+    .accesskey = O
+
+##
+
+main-context-menu-media-mute =
+    .label = Tewi
+    .accesskey = T
+
+main-context-menu-media-unmute =
+    .label = Dad-dewi
+    .accesskey = a
+
+main-context-menu-media-play-speed-2 =
+    .label = Cyflymder
+    .accesskey = C
+
+main-context-menu-media-play-speed-slow-2 =
+    .label = 0.5×
+
+main-context-menu-media-play-speed-normal-2 =
+    .label = 1.0×
+
+main-context-menu-media-play-speed-fast-2 =
+    .label = 1.25×
+
+main-context-menu-media-play-speed-faster-2 =
+    .label = 1.5×
+
+main-context-menu-media-play-speed-fastest-2 =
+    .label = 2×
+
+main-context-menu-media-loop =
+    .label = Cylchu
+    .accesskey = C
+
+## The access keys for "Show Controls" and "Hide Controls" are the same
+## because the two context-menu items are mutually exclusive.
+
+main-context-menu-media-show-controls =
+    .label = Dangos Rheolydd
+    .accesskey = R
+
+main-context-menu-media-hide-controls =
+    .label = Cuddio Rheolydd
+    .accesskey = u
+
+##
+
+main-context-menu-media-video-fullscreen =
+    .label = Sgrin Lawn
+    .accesskey = S
+
+main-context-menu-media-video-leave-fullscreen =
+    .label = Gadael Sgrin Lawn
+    .accesskey = S
+
+# This is used when right-clicking on a video in the
+# content area when the Picture-in-Picture feature is enabled.
+main-context-menu-media-watch-pip =
+    .label = Gwylio yn Llun-mewn-Llun
+    .accesskey = G
+
+main-context-menu-image-reload =
+    .label = Ail-lwytho'r Ddelwedd
+    .accesskey = D
+
+main-context-menu-image-view-new-tab =
+    .label = Agor Delwedd mewn Tab Newydd
+    .accesskey = D
+
+main-context-menu-video-view-new-tab =
+    .label = Agor Fideo mewn Tab Newydd
+    .accesskey = F
+
+main-context-menu-image-copy =
+    .label = Copïo Delwedd
+    .accesskey = D
+
+main-context-menu-image-copy-link =
+    .label = Copïo Dolen Delwedd
+    .accesskey = D
+
+main-context-menu-video-copy-link =
+    .label = Copïo Dolen Fideo
+    .accesskey = F
+
+main-context-menu-audio-copy-link =
+    .label = Copïo Dolen Sain
+    .accesskey = S
+
+main-context-menu-image-save-as =
+    .label = Cadw Delwedd Fel…
+    .accesskey = D
+
+main-context-menu-image-email =
+    .label = Delwedd E-bost…
+    .accesskey = D
+
+main-context-menu-image-set-image-as-background =
+    .label = Gosod Delwedd fel Cefndir Bwrdd Gwaith…
+    .accesskey = D
+
+main-context-menu-image-copy-text =
+    .label = Copïo Testun o Ddelwedd
+    .accesskey = T
+
+main-context-menu-image-info =
+    .label = Gwybodaeth am Weld Delwedd
+    .accesskey = D
+
+main-context-menu-image-desc =
+    .label = Gweld Disgrifiad
+    .accesskey = D
+
+main-context-menu-video-save-as =
+    .label = Cadw Fideo Fel…
+    .accesskey = F
+
+main-context-menu-audio-save-as =
+    .label = Cadw Sain Fel…
+    .accesskey = C
+
+main-context-menu-video-take-snapshot =
+    .label = Cymryd Ciplun…
+    .accesskey = C
+
+main-context-menu-video-email =
+    .label = Fideo E-bost…
+    .accesskey = F
+
+main-context-menu-audio-email =
+    .label = Sain E-bost…
+    .accesskey = S
+
+main-context-menu-plugin-play =
+    .label = Gweithredu'r ategyn
+    .accesskey = G
+
+main-context-menu-plugin-hide =
+    .label = Cuddio'r ategyn
+    .accesskey = C
+
+main-context-menu-save-to-pocket =
+    .label = Cadw Tudalen i { -pocket-brand-name }
+    .accesskey = k
+
+main-context-menu-send-to-device =
+    .label = Anfon Tudalen i Ddyfais
+    .accesskey = D
+
+## The access keys for "Use Saved Login" and "Use Saved Password"
+## should be the same if possible; the two context menu items
+## are mutually exclusive.
+
+main-context-menu-use-saved-login =
+    .label = Defnyddio Mewngofnodi wedi'i Gadw
+    .accesskey = G
+
+main-context-menu-use-saved-password =
+    .label = Defnyddio Cyfrinair wedi'i Gadw
+    .accesskey = C
+
+##
+
+main-context-menu-suggest-strong-password =
+    .label = Cynnig Cyfrinair Cryf...
+    .accesskey = C
+
+main-context-menu-manage-logins2 =
+    .label = Rheoli Mewngofnodion
+    .accesskey = R
+
+main-context-menu-keyword =
+    .label = Ychwanegu Allweddair i'r Chwilio…
+    .accesskey = Y
+
+main-context-menu-link-send-to-device =
+    .label = Anfon Dolen i Ddyfais
+    .accesskey = D
+
+main-context-menu-frame =
+    .label = Y Ffrâm
+    .accesskey = F
+
+main-context-menu-frame-show-this =
+    .label = Dangos y Ffrâm yma'n Unig
+    .accesskey = D
+
+main-context-menu-frame-open-tab =
+    .label = Agor Ffrâm mewn Tab Newydd
+    .accesskey = T
+
+main-context-menu-frame-open-window =
+    .label = Agor Ffrâm mewn Ffenestr Newydd
+    .accesskey = F
+
+main-context-menu-frame-reload =
+    .label = Ail-lwytho'r Ffrâm
+    .accesskey = r
+
+main-context-menu-frame-bookmark =
+    .label = Gosod Nod Tudalen i'r Ffrâm
+    .accesskey = F
+
+main-context-menu-frame-add-bookmark =
+    .label = Gosod Nod i Ffrâm…
+    .accesskey = F
+
+main-context-menu-frame-save-as =
+    .label = Cadw Ffrâm Fel…
+    .accesskey = F
+
+main-context-menu-frame-print =
+    .label = Argraffu'r Ffrâm…
+    .accesskey = A
+
+main-context-menu-frame-view-source =
+    .label = Edrych ar God Gwreiddiol y Ffrâm
+    .accesskey = F
+
+main-context-menu-frame-view-info =
+    .label = Edrych ar Wybodaeth am y Ffrâm
+    .accesskey = W
+
+main-context-menu-print-selection =
+    .label = Dewis Argraffu
+    .accesskey = A
+
+main-context-menu-print-selection-2 =
+    .label = Argraffu'r Dewis…
+    .accesskey = A
+
+main-context-menu-view-selection-source =
+    .label = Edrych ar Ffynhonnell y Dewis
+    .accesskey = E
+
+main-context-menu-take-screenshot =
+    .label = Cymryd Llun Sgrin
+    .accesskey = L
+
+main-context-menu-take-frame-screenshot =
+    .label = Cymryd Llun Sgrin
+    .accesskey = L
+
+main-context-menu-view-page-source =
+    .label = Edrych ar God Gwreiddiol y Dudalen
+    .accesskey = G
+
+main-context-menu-bidi-switch-text =
+    .label = Newid Cyfeiriad Testun
+    .accesskey = T
+
+main-context-menu-bidi-switch-page =
+    .label = Newid Cyfeiriad Tudalen
+    .accesskey = N
+
+main-context-menu-inspect =
+    .label = Arsylwi
+    .accesskey = A
+
+main-context-menu-inspect-a11y-properties =
+    .label = Archwilio'r Priodoleddau Hygyrchedd
+
+main-context-menu-eme-learn-more =
+    .label = Dysgu rhagor am DRM…
+    .accesskey = D
+
+# Variables
+#   $containerName (String): The name of the current container
+main-context-menu-open-link-in-container-tab =
+    .label = Agor Dolen mewn Tab { $containerName } Newydd
+    .accesskey = A
+
+main-context-menu-reveal-password =
+    .label = Datgelu Cyfrinair
+    .accesskey = D
diff --git a/l10n-cy/browser/browser/browserSets.ftl b/l10n-cy/browser/browser/browserSets.ftl
new file mode 100644
index 0000000000..e25512c353
--- /dev/null
+++ b/l10n-cy/browser/browser/browserSets.ftl
@@ -0,0 +1,218 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+window-minimize-command =
+    .label = Lleihau
+
+window-zoom-command =
+    .label = Chwyddo
+
+window-new-shortcut =
+    .key = N
+
+window-minimize-shortcut =
+    .key = m
+
+close-shortcut =
+    .key = W
+
+tab-new-shortcut =
+    .key = t
+
+location-open-shortcut =
+    .key = l
+
+location-open-shortcut-alt =
+    .key = D
+
+search-focus-shortcut =
+    .key = k
+
+# This shortcut is used in two contexts:
+#   - web search
+#   - find in page
+find-shortcut =
+    .key = f
+
+search-find-again-shortcut =
+    .key = g
+
+search-find-again-shortcut-alt =
+    .keycode = VK_F3
+
+search-find-selection-shortcut =
+    .key = e
+
+# Verify what shortcut for that operation
+# are recommended by the Human Interface Guidelines
+# of each platform for your locale.
+search-focus-shortcut-alt =
+    .key =
+        { PLATFORM() ->
+            [linux] j
+           *[other] e
+        }
+
+# Verify what shortcut for that operation
+# are recommended by the Human Interface Guidelines
+# of each platform for your locale.
+downloads-shortcut =
+    .key =
+        { PLATFORM() ->
+            [linux] y
+           *[other] j
+        }
+
+addons-shortcut =
+    .key = A
+
+file-open-shortcut =
+    .key = o
+
+save-page-shortcut =
+    .key = s
+
+page-source-shortcut =
+    .key = u
+
+# This should match the Option+Command keyboard shortcut letter that Safari
+# and Chrome use for "View Source" on macOS. `page-source-shortcut` above
+# is Firefox's official keyboard shortcut shown in the GUI.
+# Safari variant is an alias provided for the convenience of Safari and Chrome
+# users on macOS. See bug 1398988.
+page-source-shortcut-safari =
+    .key = u
+
+page-info-shortcut =
+    .key = i
+
+print-shortcut =
+    .key = p
+
+mute-toggle-shortcut =
+    .key = M
+
+nav-back-shortcut-alt =
+    .key = [
+
+nav-fwd-shortcut-alt =
+    .key = ]
+
+nav-reload-shortcut =
+    .key = r
+
+# Shortcut available only on macOS.
+nav-stop-shortcut =
+    .key = .
+
+history-show-all-shortcut =
+    .key = H
+
+history-show-all-shortcut-mac =
+    .key = Y
+
+history-sidebar-shortcut =
+    .key = h
+
+full-screen-shortcut =
+    .key = F
+
+reader-mode-toggle-shortcut-windows =
+    .keycode = VK_F9
+
+reader-mode-toggle-shortcut-other =
+    .key = R
+
+picture-in-picture-toggle-shortcut-mac =
+    .key = ]
+
+# Pick the key that is commonly present
+# in your locale keyboards above the
+# `picture-in-picture-toggle-shortcut-mac` key.
+picture-in-picture-toggle-shortcut-mac-alt =
+    .key = { "}" }
+
+picture-in-picture-toggle-shortcut =
+    .key = ]
+
+# Pick the key that is commonly present
+# in your locale keyboards above the
+# `picture-in-picture-toggle-shortcut` key.
+picture-in-picture-toggle-shortcut-alt =
+    .key = { "}" }
+
+bookmark-this-page-shortcut =
+    .key = d
+
+# Verify what shortcut for that operation
+# are recommended by the Human Interface Guidelines
+# of each platform for your locale.
+bookmark-show-library-shortcut =
+    .key = O
+
+# Verify what shortcut for that operation
+# are recommended by the Human Interface Guidelines
+# of each platform for your locale.
+bookmark-show-sidebar-shortcut =
+    .key = b
+
+# Verify what shortcut for that operation
+# are recommended by the Human Interface Guidelines
+# of each platform for your locale.
+bookmark-show-toolbar-shortcut =
+    .key = B
+
+## All `-alt*` messages are alternative acceleration keys for zoom.
+## If shift key is needed with your locale popular keyboard for them,
+## you can use these alternative items. Otherwise, their values should be empty.
+
+full-zoom-reduce-shortcut =
+    .key = -
+
+full-zoom-reduce-shortcut-alt-a =
+    .key = _
+
+full-zoom-reduce-shortcut-alt-b =
+    .key = { "" }
+
+full-zoom-enlarge-shortcut =
+    .key = +
+
+full-zoom-enlarge-shortcut-alt =
+    .key = =
+
+full-zoom-enlarge-shortcut-alt2 =
+    .key = { "" }
+
+full-zoom-reset-shortcut =
+    .key = 0
+
+full-zoom-reset-shortcut-alt =
+    .key = { "" }
+
+##
+
+bidi-switch-direction-shortcut =
+    .key = X
+
+private-browsing-shortcut =
+    .key = P
+
+## The shortcuts below are for Mac specific
+## global menu.
+
+quit-app-shortcut =
+    .key = Q
+
+help-shortcut =
+    .key = ?
+
+preferences-shortcut =
+    .key = ,
+
+hide-app-shortcut =
+    .key = H
+
+hide-other-apps-shortcut =
+    .key = H
diff --git a/l10n-cy/browser/browser/colorwaycloset.ftl b/l10n-cy/browser/browser/colorwaycloset.ftl
new file mode 100644
index 0000000000..bfa0f6f5b6
--- /dev/null
+++ b/l10n-cy/browser/browser/colorwaycloset.ftl
@@ -0,0 +1,22 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# Variables:
+#   $expiryDate (string) - date on which the colorway collection expires. When formatting this, you may omit the year, only exposing the month and day, as colorway collections will always expire within a year.
+colorway-collection-expiry-label = Yn dod i ben { DATETIME($expiryDate, month: "long", day: "numeric") }
+# Document title, not shown in the UI but exposed through accessibility APIs
+colorways-modal-title = Dewiswch Eich Cyfuniad Lliw
+colorway-intensity-selector-label = Dwysedd
+colorway-intensity-soft = Meddal
+colorway-intensity-balanced = Cytbwys
+# "Bold" is used in the sense of bravery or courage, not in the sense of
+# emphasized text.
+colorway-intensity-bold = Trwm
+# Label for the button to keep using the selected colorway in the browser
+colorway-closet-set-colorway-button = Gosod cyfuniad lliw
+colorway-closet-cancel-button = Diddymu
+colorway-homepage-reset-prompt = Gwnewch { -firefox-home-brand-name } yn gartref lliwgar i chi
+colorway-homepage-reset-success-message = { -firefox-home-brand-name } yw eich cartref nawr
+colorway-homepage-reset-apply-button = Gosod
+colorway-homepage-reset-undo-button = Dadwneud
diff --git a/l10n-cy/browser/browser/colorways.ftl b/l10n-cy/browser/browser/colorways.ftl
new file mode 100644
index 0000000000..09883509db
--- /dev/null
+++ b/l10n-cy/browser/browser/colorways.ftl
@@ -0,0 +1,26 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+## Colorway collections
+
+colorway-collection-independent-voices = Lleisiau Annibynnol
+colorway-collection-independent-voices-description = Gall lliw newid diwylliant. Mae'r cyfuniadau lliw diweddaraf yn dathlu lleisiau sy'n gwneud y byd yn lle gwell.
+# Used as a subheading for the colorway collection card in about:addons
+colorway-collection-independent-voices-short-description = Lliwiau sy'n newid diwylliant.
+
+## Colorway names and descriptions
+
+playmaker-colorway-name = Chwaraewr
+playmaker-colorway-description = Rydych chi'n creu cyfleoedd i ennill ac yn helpu pawb o'ch cwmpas i godi eu gêm.
+expressionist-colorway-name = Mynegiadwr
+expressionist-colorway-description = Rydych chi'n gweld y byd yn wahanol ac mae eich creadigaethau'n cyffroi emosiynau pobl eraill.
+visionary-colorway-name = Gweledydd
+visionary-colorway-description = Rydych chi'n cwestiynu'r status quo ac yn annog eraill i ddychmygu dyfodol gwell.
+activist-colorway-name = Ymgyrchydd
+activist-colorway-description = Rydych chi'n gadael y byd yn lle gwell nag nag oedd ac yn arwain eraill i gredu.
+dreamer-colorway-name = Breuddwydiwr
+dreamer-colorway-description = Rydych chi'n credu bod hap yn ffafrio'r beiddgar ac yn ysbrydoli eraill i fod yn ddewr.
+innovator-colorway-name = Arloesydd
+innovator-colorway-description = Rydych chi'n gweld cyfleoedd ym mhobman ac yn cael effaith ar fywydau pawb o'ch cwmpas.
diff --git a/l10n-cy/browser/browser/components/mozSupportLink.ftl b/l10n-cy/browser/browser/components/mozSupportLink.ftl
new file mode 100644
index 0000000000..e7717be948
--- /dev/null
+++ b/l10n-cy/browser/browser/components/mozSupportLink.ftl
@@ -0,0 +1,5 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+moz-support-link-text = Dysgu rhagor
diff --git a/l10n-cy/browser/browser/confirmationHints.ftl b/l10n-cy/browser/browser/confirmationHints.ftl
new file mode 100644
index 0000000000..52dc2aa2ef
--- /dev/null
+++ b/l10n-cy/browser/browser/confirmationHints.ftl
@@ -0,0 +1,15 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+## Confirmation hints
+
+confirmation-hint-breakage-report-sent = Anfonwyd yr adroddiad. Diolch!
+confirmation-hint-login-removed = Mewngofnodi wedi'i dynnu!
+confirmation-hint-page-bookmarked = Wedi'i gadw i nodau tudalen
+confirmation-hint-password-saved = Cyfrinair wedi'i gadw!
+confirmation-hint-pin-tab = Piniwyd!
+confirmation-hint-pin-tab-description = Rhowch glic de i'r tab i'w ddabinio.
+confirmation-hint-send-to-device = Anfonwyd!
+confirmation-hint-firefox-relay-mask-generated = Arallenw { -relay-brand-short-name } newydd wedi'i gynhyrchu!
diff --git a/l10n-cy/browser/browser/contentCrash.ftl b/l10n-cy/browser/browser/contentCrash.ftl
new file mode 100644
index 0000000000..44e1923773
--- /dev/null
+++ b/l10n-cy/browser/browser/contentCrash.ftl
@@ -0,0 +1,38 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+## Subframe crash notification
+
+crashed-subframe-message = <strong>Mae rhan o'r dudalen hon wedi chwalu.</strong> Er mwyn rhoi gwybod i { -brand-product-name } am y mater hwn a'i drwsio'n gynt, cyflwynwch adroddiad.
+
+# The string for crashed-subframe-title.title should match crashed-subframe-message,
+# but without any markup.
+crashed-subframe-title =
+    .title = <strong>Mae rhan o'r dudalen hon wedi chwalu.</strong> Er mwyn rhoi gwybod i { -brand-product-name } am y mater hwn a'i drwsio'n gynt, cyflwynwch adroddiad.
+crashed-subframe-learnmore-link =
+    .value = Dysgu Rhagor
+crashed-subframe-submit =
+    .label = Cyflwyno Adroddiad
+    .accesskey = A
+
+## Pending crash reports
+
+# Variables:
+#   $reportCount (Number): the number of pending crash reports
+pending-crash-reports-message =
+    { $reportCount ->
+        [zero] Nid oes gennych adroddiad chwalu sydd heb ei gyflwyno
+        [one] Mae gennych { $reportCount } adroddiad chwalu sydd heb ei gyflwyno
+        [two] Mae gennych { $reportCount } adroddiad chwalu sydd heb eu cyflwyno
+        [few] Mae gennych { $reportCount } adroddiad chwalu sydd heb eu cyflwyno
+        [many] Mae gennych { $reportCount } adroddiad chwalu sydd heb eu cyflwyno
+       *[other] Mae gennych { $reportCount } adroddiad chwalu sydd heb eu cyflwyno
+    }
+pending-crash-reports-view-all =
+    .label = Gweld
+pending-crash-reports-send =
+    .label = Anfon
+pending-crash-reports-always-send =
+    .label = Anfon Bob Tro
diff --git a/l10n-cy/browser/browser/customizeMode.ftl b/l10n-cy/browser/browser/customizeMode.ftl
new file mode 100644
index 0000000000..e78be9a582
--- /dev/null
+++ b/l10n-cy/browser/browser/customizeMode.ftl
@@ -0,0 +1,38 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+customize-mode-restore-defaults =
+    .label = Adfer y Rhagosodiadau
+customize-mode-menu-and-toolbars-header = Llusgwch eich hoff eitemau i'r bar offer neu'r ddewislen ychwanegol.
+customize-mode-overflow-list-title = Dewislen Gorlif
+customize-mode-uidensity =
+    .label = Dwysedd
+customize-mode-done =
+    .label = Gorffen
+customize-mode-toolbars =
+    .label = Barrau Offer
+customize-mode-titlebar =
+    .label = Bar Teitl
+customize-mode-uidensity-menu-touch =
+    .label = Cyffwrdd
+    .accesskey = C
+    .tooltiptext = Cyffwrdd
+customize-mode-uidensity-auto-touch-mode-checkbox =
+    .label = Defnyddio Cyffwrdd ar gyfer y Modd Tabled
+customize-mode-overflow-list-description = Llusgwch a gollwng yr eitemau hyn yma i'w cadw o fewn cyrraedd ond allan o'ch bar offer…
+customize-mode-uidensity-menu-normal =
+    .label = Arferol
+    .accesskey = A
+    .tooltiptext = Arferol
+customize-mode-uidensity-menu-compact-unsupported =
+    .label = Cryno (heb ei gefnogi)
+    .accesskey = r
+    .tooltiptext = Cryno (heb ei gefnogi)
+customize-mode-undo-cmd =
+    .label = Dadwneud
+customize-mode-lwthemes-link = Rheoli Themâu
+customize-mode-touchbar-cmd =
+    .label = Cyfaddasu'r Bar Cyffwrdd…
+customize-mode-downloads-button-autohide =
+    .label = Cuddio'r botwm pan yn wag
diff --git a/l10n-cy/browser/browser/defaultBrowserNotification.ftl b/l10n-cy/browser/browser/defaultBrowserNotification.ftl
new file mode 100644
index 0000000000..01b0aa8c6e
--- /dev/null
+++ b/l10n-cy/browser/browser/defaultBrowserNotification.ftl
@@ -0,0 +1,23 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# The question portion of the following message should have the <strong> and </strong> tags surrounding it.
+default-browser-notification-message = <strong>Gosodwch { -brand-short-name } fel eich porwr rhagosodedig? </strong>Cewch bori'n gyflym, yn ddiogel ac yn breifat pryd bynnag y byddwch yn defnyddio'r we.
+default-browser-notification-button =
+    .label = Gosod fel y Rhagosodiad
+    .accesskey = R
+
+## These strings are used for the default browser prompt. There are 2 variations
+## depending on the operating system (Windows vs other). The checkbox label and
+## secondary button are shared between the variants.
+
+default-browser-prompt-title-pin = Gwneud { -brand-short-name } eich prif borwr?
+default-browser-prompt-message-pin = Cadwch { -brand-short-name } ar flaenau eich bysedd — ei wneud eich porwr rhagosodedig a'i binio i'ch bar tasgau.
+default-browser-prompt-message-pin-mac = Cadwch { -brand-short-name } wrth law — ei wneud eich prif borwr a'i gadw'n eich Doc.
+default-browser-prompt-button-primary-pin = Ei wneud eich prif borwr
+default-browser-prompt-title-alt = Gwneud { -brand-short-name } eich prif borwr?
+default-browser-prompt-message-alt = Cael cyflymder, diogelwch a phreifatrwydd bob tro y byddwch chi'n pori.
+default-browser-prompt-button-primary-alt = Gosod fel y porwr ragosodedig
+default-browser-prompt-checkbox-not-again-label = Peidio â dangos y neges hon eto
+default-browser-prompt-button-secondary = Nid nawr
diff --git a/l10n-cy/browser/browser/downloads.ftl b/l10n-cy/browser/browser/downloads.ftl
new file mode 100644
index 0000000000..638182096f
--- /dev/null
+++ b/l10n-cy/browser/browser/downloads.ftl
@@ -0,0 +1,246 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+## The title and aria-label attributes are used by screen readers to describe
+## the Downloads Panel.
+
+downloads-window =
+    .title = Llwythi
+downloads-panel =
+    .aria-label = Llwythi
+
+##
+
+# The style attribute has the width of the Downloads Panel expressed using
+# a CSS unit. The longest labels that should fit are usually those of
+# in-progress and blocked downloads.
+downloads-panel-items =
+    .style = width: 35em
+downloads-cmd-pause =
+    .label = Oedi
+    .accesskey = O
+downloads-cmd-resume =
+    .label = Ailgychwyn
+    .accesskey = A
+downloads-cmd-cancel =
+    .tooltiptext = Diddymu
+downloads-cmd-cancel-panel =
+    .aria-label = Diddymu
+downloads-cmd-show-menuitem-2 =
+    .label =
+        { PLATFORM() ->
+            [macos] Dangos yn Finder
+           *[other] Dangos mewn Ffolder
+        }
+    .accesskey = D
+
+## Displayed in the downloads context menu for files that can be opened.
+## Variables:
+##   $handler (String) - The name of the mime type's default file handler.
+##   Example: "Notepad", "Acrobat Reader DC", "7-Zip File Manager"
+
+downloads-cmd-use-system-default =
+    .label = Agor yn Narllenydd System
+    .accesskey = N
+# This version is shown when the download's mime type has a valid file handler.
+downloads-cmd-use-system-default-named =
+    .label = Agor yn { $handler }
+    .accesskey = A
+# We can use the same accesskey as downloads-cmd-always-open-similar-files.
+# Both should not be visible in the downloads context menu at the same time.
+downloads-cmd-always-use-system-default =
+    .label = Agor Bob Tro mewn Darllenydd System
+    .accesskey = B
+# We can use the same accesskey as downloads-cmd-always-open-similar-files.
+# Both should not be visible in the downloads context menu at the same time.
+# This version is shown when the download's mime type has a valid file handler.
+downloads-cmd-always-use-system-default-named =
+    .label = Agor bob tro yn { $handler }
+    .accesskey = t
+
+##
+
+# We can use the same accesskey as downloads-cmd-always-use-system-default.
+# Both should not be visible in the downloads context menu at the same time.
+downloads-cmd-always-open-similar-files =
+    .label = Agor Ffeiliau Tebyg Bob Tro
+    .accesskey = T
+downloads-cmd-show-button-2 =
+    .tooltiptext =
+        { PLATFORM() ->
+            [macos] Dangos yn Finder
+           *[other] Dangos mewn Ffolder
+        }
+downloads-cmd-show-panel-2 =
+    .aria-label =
+        { PLATFORM() ->
+            [macos] Dangos yn Finder
+           *[other] Dangos mewn Ffolder
+        }
+downloads-cmd-show-description-2 =
+    .value =
+        { PLATFORM() ->
+            [macos] Dangos yn Finder
+           *[other] Dangos mewn Ffolder
+        }
+downloads-cmd-show-downloads =
+    .label = Dangos y Ffowleder Llwythi
+downloads-cmd-retry =
+    .tooltiptext = Ceisio eto
+downloads-cmd-retry-panel =
+    .aria-label = Ceisio eto
+downloads-cmd-go-to-download-page =
+    .label = Mynd i'r Dudalen Llwytho i Lawr
+    .accesskey = M
+downloads-cmd-copy-download-link =
+    .label = Copïo Dolen Llwytho i Lawr
+    .accesskey = C
+downloads-cmd-remove-from-history =
+    .label = Tynnu o'r Hanes
+    .accesskey = y
+downloads-cmd-clear-list =
+    .label = Clirio'r Panel Rhagolwg
+    .accesskey = r
+downloads-cmd-clear-downloads =
+    .label = Clirio Llwythi
+    .accesskey = L
+downloads-cmd-delete-file =
+    .label = Dileu
+    .accesskey = D
+# This command is shown in the context menu when downloads are blocked.
+downloads-cmd-unblock =
+    .label = Caniatáu Llwytho i Lawr
+    .accesskey = a
+# This is the tooltip of the action button shown when malware is blocked.
+downloads-cmd-remove-file =
+    .tooltiptext = Tynnu Ffeil
+downloads-cmd-remove-file-panel =
+    .aria-label = Tynnu Ffeil
+# This is the tooltip of the action button shown when potentially unwanted
+# downloads are blocked. This opens a dialog where the user can choose
+# whether to unblock or remove the download. Removing is the default option.
+downloads-cmd-choose-unblock =
+    .tooltiptext = Tynnu Ffeil neu Ganiatáu Llwytho i Lawr
+downloads-cmd-choose-unblock-panel =
+    .aria-label = Tynnu Ffeil neu Ganiatáu Llwytho i Lawr
+# This is the tooltip of the action button shown when uncommon downloads are
+# blocked.This opens a dialog where the user can choose whether to open the
+# file or remove the download. Opening is the default option.
+downloads-cmd-choose-open =
+    .tooltiptext = Agor neu Dynnu'r Ffeil
+downloads-cmd-choose-open-panel =
+    .aria-label = Agor neu Dynnu'r Ffeil
+# Displayed when hovering a blocked download, indicates that it's possible to
+# show more information for user to take the next action.
+downloads-show-more-information =
+    .value = Dangos rhagor o wybodaeth
+# Displayed when hovering a complete download, indicates that it's possible to
+# open the file using an app available in the system.
+downloads-open-file =
+    .value = Agor Ffeil
+
+## Displayed when the user clicked on a download in process. Indicates that the
+## downloading file will be opened after certain amount of time using an app
+## available in the system.
+## Variables:
+##   $hours (number) - Amount of hours left till the file opens.
+##   $seconds (number) - Amount of seconds left till the file opens.
+##   $minutes (number) - Amount of minutes till the file opens.
+
+downloading-file-opens-in-hours-and-minutes = Yn agor ymhen { $hours }a { $minutes }m…
+downloading-file-opens-in-minutes = Yn agor ymhen { $minutes }m…
+downloading-file-opens-in-minutes-and-seconds = Yn agor ymhen { $minutes }m { $seconds }e…
+downloading-file-opens-in-seconds = Yn agor ymhen { $seconds }e…
+downloading-file-opens-in-some-time = Yn agor pan fydd wedi ei gwblhau…
+downloading-file-opens-in-hours-and-minutes-2 =
+    .value = Yn agor ymhen { $hours }a { $minutes }m…
+downloading-file-opens-in-minutes-2 =
+    .value = Yn agor ymhen { $minutes }m…
+downloading-file-opens-in-minutes-and-seconds-2 =
+    .value = Yn agor ymhen { $minutes }m { $seconds }e…
+downloading-file-opens-in-seconds-2 =
+    .value = Yn agor ymhen { $seconds }e…
+downloading-file-opens-in-some-time-2 =
+    .value = Yn agor pan fydd wedi ei gwblhau…
+downloading-file-click-to-open =
+    .value = Ar agor pan fydd wedi ei gwblhau
+
+##
+
+# Displayed when hovering a download which is able to be retried by users,
+# indicates that it's possible to download this file again.
+downloads-retry-download =
+    .value = Ceisio Llwytho i Lawr Eto
+# Displayed when hovering a download which is able to be cancelled by users,
+# indicates that it's possible to cancel and stop the download.
+downloads-cancel-download =
+    .value = Diddymu Llwytho i Lawr
+# This string is shown at the bottom of the Downloads Panel when all the
+# downloads fit in the available space, or when there are no downloads in
+# the panel at all.
+downloads-history =
+    .label = Dangos Pob Llwyth
+    .accesskey = D
+# This string is shown at the top of the Download Details Panel, to indicate
+# that we are showing the details of a single download.
+downloads-details =
+    .title = Manylion y Llwytho i Lawr
+
+## Displayed when a site attempts to automatically download many files.
+## Variables:
+##   $num (number) - Number of blocked downloads.
+##   $url (string) - The url of the suspicious site, stripped of http, https and www prefix.
+
+downloads-files-not-downloaded =
+    { $num ->
+        [zero] Dim ffeiliau wedi'u llwytho i lawr.
+        [one] Ffeil heb ei llwytho i lawr.
+        [two] { $num } ffeil heb eu llwytho i lawr.
+        [few] { $num } ffeil heb eu llwytho i lawr.
+        [many] { $num } ffeil heb eu llwytho i lawr.
+       *[other] { $num } ffeil heb eu llwytho i lawr.
+    }
+downloads-blocked-from-url = Wedi rhwystro llwytho ffeiliau i lawr o { $url }.
+downloads-blocked-download-detailed-info = Ceisiodd { $url } lwytho ffeiliau lluosog i lawr yn awtomatig. Efallai fod y wefan wedi torri neu'n ceisio storio ffeiliau sbam ar eich dyfais.
+
+##
+
+downloads-clear-downloads-button =
+    .label = Clirio'r Llwythi
+    .tooltiptext = Yn clirio llwythi cwblhawyd, dilëwyd a methwyd
+# This string is shown when there are no items in the Downloads view, when it
+# is displayed inside a browser tab.
+downloads-list-empty =
+    .value = Nid oes llwythi.
+# This string is shown when there are no items in the Downloads Panel.
+downloads-panel-empty =
+    .value = Dim llwytho i lawr yn ystod y sesiwn yma.
+# This is displayed in an item at the bottom of the Downloads Panel when there
+# are more downloads than can fit in the list in the panel.
+#   $count (number) - number of files being downloaded that are not shown in the
+#                     panel list.
+downloads-more-downloading =
+    { $count ->
+        [zero] Dim rhagor o ffeiliau i'w llwytho i lawr
+        [one] { $count } ffeil arall yn llwytho i lawr
+        [two] { $count } ffeil arall yn llwytho i lawr
+        [few] { $count } ffeil arall yn llwytho i lawr
+        [many] { $count } ffeil arall yn llwytho i lawr
+       *[other] { $count } ffeil arall yn llwytho i lawr
+    }
+
+## Download errors
+
+downloads-error-alert-title = Gwall llwytho i lawr
+# Variables:
+#   $extension (String): the name of the blocking extension.
+downloads-error-blocked-by = Nid oes modd cadw'r llwyth am ei fod wedi'i rwystro gan { $extension }.
+# Used when the name of the blocking extension is unavailable.
+downloads-error-extension = Nid oes modd cadw'r llwyth am ei fod wedi'i rwystro gan estyniad.
+# Line breaks in this message are meaningful, and should be maintained.
+downloads-error-generic =
+    Nid oes modd cadw'r llwyth yma gan fod gwall anhysbys wedi digwydd.
+    
+    Ceisiwch eto.
diff --git a/l10n-cy/browser/browser/editBookmarkOverlay.ftl b/l10n-cy/browser/browser/editBookmarkOverlay.ftl
new file mode 100644
index 0000000000..4c8ce09539
--- /dev/null
+++ b/l10n-cy/browser/browser/editBookmarkOverlay.ftl
@@ -0,0 +1,49 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+bookmark-overlay-name-2 =
+    .value = Enw
+    .accesskey = E
+
+bookmark-overlay-url =
+    .value = URL
+    .accesskey = U
+
+# Location refers to the position of the bookmark within the browser's
+# bookmarks, not to its URL or address.
+bookmark-overlay-location-2 =
+    .value = Lleoliad
+    .accesskey = L
+
+bookmark-overlay-choose =
+    .label = Dewis…
+
+bookmark-overlay-folders-expander =
+    .tooltiptext = Dangos pob ffolder nod tudalen
+    .tooltiptextdown = { bookmark-overlay-folders-expander.tooltiptext }
+    .tooltiptextup = Cuddio
+
+bookmark-overlay-new-folder-button =
+    .label = Ffolder Newydd
+    .accesskey = N
+
+bookmark-overlay-tags-2 =
+    .value = Tagiau
+    .accesskey = T
+
+bookmark-overlay-tags-empty-description =
+    .placeholder = Gwahanu tagiau gydag atalnod
+
+bookmark-overlay-tags-expander =
+    .tooltiptext = Dangos pob tag
+    .tooltiptextdown = { bookmark-overlay-tags-expander.tooltiptext }
+    .tooltiptextup = Cuddio
+
+bookmark-overlay-keyword-2 =
+    .value = Allweddair
+    .accesskey = A
+
+bookmark-overlay-tags-caption-label = Defnyddiwch dagiau i drefnu a chwilio am nodau tudalen o'r bar cyfeiriadau
+
+bookmark-overlay-keyword-caption-label-2 = Defnyddio'r un allweddair i agor nodau tudalen yn uniongyrchol o'r bar cyfeiriad
diff --git a/l10n-cy/browser/browser/featureCallout.ftl b/l10n-cy/browser/browser/featureCallout.ftl
new file mode 100644
index 0000000000..e2bff085ab
--- /dev/null
+++ b/l10n-cy/browser/browser/featureCallout.ftl
@@ -0,0 +1,45 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# Callout dialog primary button to advance to next screen
+callout-primary-advance-button-label = Nesaf
+# Callout dialog primary button to complete the feature tour
+callout-primary-complete-button-label = Iawn!
+
+## Firefox View feature tour strings
+
+# "Tab pickup" refers to the section in Firefox View that displays open
+# tabs from other devices
+callout-firefox-view-tab-pickup-title = Symudwch rhwng dyfeisiau gyda chipio tabiau
+callout-firefox-view-tab-pickup-subtitle = Cipiwch dabiau agored yn gyflym o'ch ffôn a'u hagor yma i gael y llif gorau.
+callout-firefox-view-recently-closed-title = Ail-agorwch eich tabiau caeedig mewn chwinciad
+callout-firefox-view-recently-closed-subtitle = Bydd eich holl dabiau caeedig yn ymddangos yn hudol yma. Peidiwch byth â phoeni am gau gwefan ar ddamwain eto.
+callout-firefox-view-colorways-title = Ychwanegwch bach o liw
+# "Shade" refer to different color options in each colorway.
+callout-firefox-view-colorways-subtitle = Dewiswch yr arlliw sy'n siarad â chi gyda chyfuniadau lliw. Dim ond yn { -brand-product-name }.
+callout-firefox-view-colorways-reminder-title = Archwiliwch ein cyfuniadau lliw diweddaraf
+# “Shades” refers to the different color options in each colorways
+callout-firefox-view-colorways-reminder-subtitle = Lliwiwch eich porwr gyda'r arlliwiau eiconig hyn, wedi'u hysbrydoli gan leisiau annibynnol. Dim ond yn { -brand-product-name }.
+
+## Continuous Onboarding - Firefox View: Tab pick up
+
+# “Boost your browsing” refers to the added benefit the user receives from having
+# access to the same browsing experience when moving from one browser to another.
+# Alternative: ”Improve your browsing experience with tab pickup”
+continuous-onboarding-firefox-view-tab-pickup-title = Rhowch hwb i'ch pori trwy ailagor tab
+continuous-onboarding-firefox-view-tab-pickup-subtitle = Cyrchwch eich tabiau agored o unrhyw ddyfais. Hefyd cydweddwch eich nodau tudalen, cyfrineiriau, a rhagor.
+continuous-onboarding-firefox-view-tab-pickup-primary-button-label = Cychwyn arni
+
+## PDF.js Feature Tour Strings
+
+callout-pdfjs-edit-title = Golygwch PDFs gyda'n teclyn testun newydd
+callout-pdfjs-edit-body-a = Llenwch ffurflenni, ychwanegu sylwadau, neu gymryd nodiadau yn uniongyrchol o fewn { -brand-short-name }.
+callout-pdfjs-edit-body-b = Gallwch hepgor y chwilio am olygyddion ar-lein am ddim. Llenwch ffurflenni, ychwanegu sylwadau, neu gymryd nodiadau yn syth o fewn { -brand-short-name }.
+callout-pdfjs-edit-button = Nesaf
+callout-pdfjs-draw-title = Llofnodwch ddogfennau gyda'n teclyn lluniadu newydd
+# “Mark up” refers to the process of “annotating” or adding free hand text or diagramming to the document.
+callout-pdfjs-draw-body-a = Marciwch PDFs, yna cadwch eich newidiadau.
+# “Mark up” refers to the process of “annotating” or adding free hand text or diagramming to the document.
+callout-pdfjs-draw-body-b = Dim mwy o argraffu a sganio. Marciwch PDFau ac yna cadw'ch newidiadau.
+callout-pdfjs-draw-button = Iawn!
diff --git a/l10n-cy/browser/browser/firefoxRelay.ftl b/l10n-cy/browser/browser/firefoxRelay.ftl
new file mode 100644
index 0000000000..db327253e3
--- /dev/null
+++ b/l10n-cy/browser/browser/firefoxRelay.ftl
@@ -0,0 +1,32 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+## Error messages for failed HTTP web requests.
+## https://developer.mozilla.org/en-US/docs/Web/HTTP/Status#client_error_responses
+## Variables:
+##   $status (Number) - HTTP status code, for example 403
+
+firefox-relay-mask-generation-failed = Nid oedd modd i { -relay-brand-name } gynhyrchu arallenwnewydd. Cod gwall HTTP: { $status }.
+firefox-relay-get-reusable-masks-failed = Nid oedd modd i { -relay-brand-name } ddod o hyd i arallenwau y mae modd eu hailddefnyddio. Cod gwall HTTP: { $status }.
+
+##
+
+firefox-relay-must-login-to-fxa = Rhaid mewngofnodi i { -fxaccount-brand-name } er mwyn defnyddio { -relay-brand-name }.
+firefox-relay-get-unlimited-masks =
+    .label = Rheoli arallenwau
+    .accesskey = R
+firefox-relay-opt-in-title = Diogelwch eich cyfeiriad e-bost
+firefox-relay-opt-in-subtitle = Ychwanegwch { -relay-brand-name }
+firefox-relay-generate-mask-title = Diogelwch eich cyfeiriad e-bost
+firefox-relay-generate-mask-subtitle = Cynhyrchwch arallenw { -relay-brand-short-name }
+firefox-relay-opt-in-confirmation-enable =
+    .label = Parhau
+    .accesskey = P
+firefox-relay-opt-in-confirmation-disable =
+    .label = Peidio â dangos hwn i mi eto
+    .accesskey = P
+firefox-relay-opt-in-confirmation-postpone =
+    .label = Nid nawr
+    .accesskey = N
diff --git a/l10n-cy/browser/browser/firefoxView.ftl b/l10n-cy/browser/browser/firefoxView.ftl
new file mode 100644
index 0000000000..0b62c81a5b
--- /dev/null
+++ b/l10n-cy/browser/browser/firefoxView.ftl
@@ -0,0 +1,84 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+toolbar-button-firefox-view =
+    .label = { -firefoxview-brand-name }
+    .tooltiptext = { -firefoxview-brand-name }
+menu-tools-firefox-view =
+    .label = { -firefoxview-brand-name }
+    .accesskey = F
+firefoxview-page-title = { -firefoxview-brand-name }
+firefoxview-close-button =
+    .title = Cau
+    .aria-label = Cau
+# Used instead of the localized relative time when a timestamp is within a minute or so of now
+firefoxview-just-now-timestamp = Newydd ddigwydd
+# This is a headline for an area in the product where users can resume and re-open tabs they have previously viewed on other devices.
+firefoxview-tabpickup-header = Ail agor tabiau
+firefoxview-tabpickup-description = Agorwch dudalennau o ddyfeisiau eraill.
+# Variables:
+#  $percentValue (Number): the percentage value for setup completion
+firefoxview-tabpickup-progress-label = { $percentValue }% wedi'i gwblhau
+firefoxview-tabpickup-step-signin-header = Symud yn rhwydd rhwng dyfeisiau
+firefoxview-tabpickup-step-signin-description = I ddefnyddio'ch tabiau ffôn yma, mewngofnodwch yn gyntaf neu greu cyfrif.
+firefoxview-tabpickup-step-signin-primarybutton = Parhau
+firefoxview-tabpickup-adddevice-header = Cydweddu { -brand-product-name } ar eich ffôn neu dabled
+firefoxview-tabpickup-adddevice-description = Llwytho { -brand-product-name } ar gyfer ffôn symudol a mewngofnodi yno.
+firefoxview-tabpickup-adddevice-learn-how = Sut mae gwneud
+firefoxview-tabpickup-adddevice-primarybutton = Cael { -brand-product-name } ar gyfer symudol
+firefoxview-tabpickup-synctabs-header = Cychwyn cydweddu tabiau
+firefoxview-tabpickup-synctabs-description = Caniatáu i { -brand-short-name } rannu tabiau rhwng dyfeisiau.
+firefoxview-tabpickup-synctabs-learn-how = Sut mae gwneud
+firefoxview-tabpickup-synctabs-primarybutton = Cydweddu tabiau agored
+firefoxview-tabpickup-fxa-admin-disabled-header = Mae eich sefydliad wedi analluogi cydweddu
+firefoxview-tabpickup-fxa-admin-disabled-description = Nid yw { -brand-short-name } yn gallu cydweddu tabiau rhwng dyfeisiau oherwydd bod eich gweinyddwr wedi analluogi cydweddu.
+firefoxview-tabpickup-network-offline-header = Gwiriwch eich cysylltiad rhwydwaith
+firefoxview-tabpickup-network-offline-description = Os ydych yn defnyddio mur cadarn neu ddirprwy, gwiriwch fod gan { -brand-short-name } ganiatâd i gael mynediad i'r we.
+firefoxview-tabpickup-network-offline-primarybutton = Ceisiwch eto
+firefoxview-tabpickup-sync-error-header = Rydyn ni'n cael trafferth cydweddu
+firefoxview-tabpickup-generic-sync-error-description = Nid yw { -brand-short-name } yn gallu cyrraedd y gwasanaeth ar hyn o bryd. Ceisiwch eto mewn ychydig eiliadau.
+firefoxview-tabpickup-sync-error-primarybutton = Ceisiwch eto
+firefoxview-tabpickup-sync-disconnected-header = Trowch gydweddu ymlaen i barhau
+firefoxview-tabpickup-sync-disconnected-description = I gipio eich tabiau, bydd angen i chi ganiatáu cydweddu yn { -brand-short-name }.
+firefoxview-tabpickup-sync-disconnected-primarybutton = Trowch cydweddu ymlaen yn y gosodiadau
+firefoxview-tabpickup-password-locked-header = Rhowch eich Prif Gyfrinair i weld tabiau
+firefoxview-tabpickup-password-locked-description = I gipio'ch tabiau, bydd angen i chi roi eich Prif Gyfrinair ar gyfer { -brand-short-name }.
+firefoxview-tabpickup-password-locked-link = Dysgu rhagor
+firefoxview-tabpickup-password-locked-primarybutton = Rhowch Gyfrinair Cynradd
+firefoxview-tabpickup-signed-out-header = Mewngofnodi i ailgysylltu
+firefoxview-tabpickup-signed-out-description = I ailgysylltu a chipio eich tabiau, mewngofnodwch i'ch { -fxaccount-brand-name }.
+firefoxview-tabpickup-signed-out-primarybutton = Mewngofnodi
+firefoxview-tabpickup-syncing = Arhoswch tra bod eich tabiau'n cydweddu. Fydd hi ddim yn hir.
+firefoxview-mobile-promo-header = Cydiwch mewn tabiau o'ch ffôn neu dabled
+firefoxview-mobile-promo-description = I weld eich tabiau symudol diweddaraf, mewngofnodwch i { -brand-product-name } ar iOS neu Android.
+firefoxview-mobile-promo-primarybutton = Cael { -brand-product-name } ar gyfer symudol
+firefoxview-mobile-confirmation-header = Barod i fynd!
+firefoxview-mobile-confirmation-description = Nawr gallwch chi gydio ar eich tabiau { -brand-product-name } o'ch tabled neu ffôn.
+firefoxview-closed-tabs-title = Caewyd yn ddiweddar
+firefoxview-closed-tabs-description2 = Ail-agorwch dudalennau rydych wedi'u cau yn y ffenestr hon.
+firefoxview-closed-tabs-placeholder-header = Dim tabiau sydd wedi'u cau yn ddiweddar
+firefoxview-closed-tabs-placeholder-body = Pan fyddwch yn cau tab yn y ffenestr hon, gallwch chi ei nôl o'r fan hon.
+# Variables:
+#   $tabTitle (string) - Title of tab being dismissed
+firefoxview-closed-tabs-dismiss-tab =
+    .title = Cau { $tabTitle }
+# refers to the last tab that was used
+firefoxview-pickup-tabs-badge = Gweithgaredd diwethaf
+# Variables:
+#   $targetURI (string) - URL that will be opened in the new tab
+firefoxview-tabs-list-tab-button =
+    .title = Agor { $targetURI } mewn tab newydd
+firefoxview-try-colorways-button = Rhowch gynnig ar gyfuniadau lliw
+firefoxview-no-current-colorway-collection = Mae cyfuniadau lliw newydd ar y ffordd
+firefoxview-change-colorway-button = Newid y llwybr lliw
+# Variables:
+#  $intensity (String): Colorway intensity
+#  $collection (String): Colorway Collection name
+firefoxview-colorway-description = { $intensity } · { $collection }
+firefoxview-synced-tabs-placeholder-header = Dim byd i'w weld eto
+firefoxview-synced-tabs-placeholder-body = Y tro nesaf y byddwch yn agor tudalen yn { -brand-product-name } ar ddyfais arall, cydiwch ynddo yma.
+firefoxview-collapse-button-show =
+    .title = Dangos rhestr
+firefoxview-collapse-button-hide =
+    .title = Cuddio rhestr
diff --git a/l10n-cy/browser/browser/menubar.ftl b/l10n-cy/browser/browser/menubar.ftl
new file mode 100644
index 0000000000..1edad9c60b
--- /dev/null
+++ b/l10n-cy/browser/browser/menubar.ftl
@@ -0,0 +1,345 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+# NOTE: For English locales, strings in this file should be in APA-style Title Case.
+# See https://apastyle.apa.org/style-grammar-guidelines/capitalization/title-case
+#
+# NOTE: For Engineers, please don't re-use these strings outside of the menubar.
+
+
+## Application Menu (macOS only)
+
+menu-application-preferences =
+    .label = Dewisiadau
+menu-application-services =
+    .label = Gwasanaethau
+menu-application-hide-this =
+    .label = Cuddio { -brand-shorter-name }
+menu-application-hide-other =
+    .label = Cuddio Eraill
+menu-application-show-all =
+    .label = Dangos Popeth
+menu-application-touch-bar =
+    .label = Cyfaddasu'r Bar Cyffwrdd…
+
+##
+
+# These menu-quit strings are only used on Windows and Linux.
+menu-quit =
+    .label =
+        { PLATFORM() ->
+            [windows] Gadael
+           *[other] Gadael
+        }
+    .accesskey =
+        { PLATFORM() ->
+            [windows] G
+           *[other] G
+        }
+# This menu-quit-mac string is only used on macOS.
+menu-quit-mac =
+    .label = Gadael { -brand-shorter-name }
+menu-about =
+    .label = Ynghylch { -brand-shorter-name }
+    .accesskey = n
+
+## File Menu
+
+menu-file =
+    .label = Ffeil
+    .accesskey = F
+menu-file-new-tab =
+    .label = Tab Newydd
+    .accesskey = T
+menu-file-new-container-tab =
+    .label = Tab Cynhwysydd Newydd
+    .accesskey = y
+menu-file-new-window =
+    .label = Ffenestr Newydd
+    .accesskey = N
+menu-file-new-private-window =
+    .label = Ffenestr Breifat Newydd
+    .accesskey = B
+# "Open Location" is only displayed on macOS, and only on windows
+# that aren't main browser windows, or when there are no windows
+# but Firefox is still running.
+menu-file-open-location =
+    .label = Agor Lleoliad…
+menu-file-open-file =
+    .label = Agor Ffeil…
+    .accesskey = F
+# Variables:
+#  $tabCount (Number): the number of tabs that are affected by the action.
+menu-file-close-tab =
+    .label =
+        { $tabCount ->
+            [1] Cau Tab
+            [zero] Cau { $tabCount } Tab
+            [one] Cau { $tabCount } Tab
+            [two] Cau { $tabCount } Dab
+            [few] Cau { $tabCount } Thab
+            [many] Cau { $tabCount } Thab
+           *[other] Cau { $tabCount } Tab
+        }
+    .accesskey = C
+menu-file-close-window =
+    .label = Cau Ffenestr
+    .accesskey = F
+menu-file-save-page =
+    .label = Cadw Tudalen Fel…
+    .accesskey = C
+menu-file-email-link =
+    .label = E-bostio'r Ddolen…
+    .accesskey = E
+menu-file-share-url =
+    .label = Rhannu
+    .accesskey = R
+menu-file-print-setup =
+    .label = Gosodiad Tudalen…
+    .accesskey = o
+menu-file-print =
+    .label = Argraffu…
+    .accesskey = A
+menu-file-import-from-another-browser =
+    .label = Mewnforio o Borwr Arall…
+    .accesskey = M
+menu-file-go-offline =
+    .label = Gweithio All-lein
+    .accesskey = w
+
+## Edit Menu
+
+menu-edit =
+    .label = Golygu
+    .accesskey = G
+menu-edit-find-in-page =
+    .label = Canfod ar y Dudalen…
+    .accesskey = D
+menu-edit-find-again =
+    .label = Canfod Eto
+    .accesskey = E
+menu-edit-bidi-switch-text-direction =
+    .label = Newid Cyfeiriad Testun
+    .accesskey = T
+
+## View Menu
+
+menu-view =
+    .label = Golwg
+    .accesskey = o
+menu-view-toolbars-menu =
+    .label = Barrau Offer
+    .accesskey = B
+menu-view-customize-toolbar2 =
+    .label = Cyfaddasu'r Bar Offer…
+    .accesskey = B
+menu-view-sidebar =
+    .label = Bar Ochr
+    .accesskey = B
+menu-view-bookmarks =
+    .label = Nodau Tudalen
+menu-view-history-button =
+    .label = Hanes
+menu-view-synced-tabs-sidebar =
+    .label = Tabiau wedi'u Cydweddu
+menu-view-full-zoom =
+    .label = Chwyddo
+    .accesskey = h
+menu-view-full-zoom-enlarge =
+    .label = Chwyddo Mewn
+    .accesskey = M
+menu-view-full-zoom-reduce =
+    .label = Chwyddo Allan
+    .accesskey = A
+menu-view-full-zoom-actual-size =
+    .label = Maint Gwirioneddol
+    .accesskey = M
+menu-view-full-zoom-toggle =
+    .label = Chwyddo'r Testun yn Unig
+    .accesskey = T
+menu-view-page-style-menu =
+    .label = Arddull Tudalen
+    .accesskey = A
+menu-view-page-style-no-style =
+    .label = Dim Arddull
+    .accesskey = D
+menu-view-page-basic-style =
+    .label = Arddull Tudalen Sylfaenol
+    .accesskey = S
+menu-view-repair-text-encoding =
+    .label = Trwsio Amgodio Testun
+    .accesskey = T
+
+## These should match what Safari and other Apple applications
+## use on macOS.
+
+menu-view-enter-full-screen =
+    .label = Mynd i Sgrin Lawn
+    .accesskey = S
+menu-view-exit-full-screen =
+    .label = Gadael Sgrin Lawn
+    .accesskey = L
+menu-view-full-screen =
+    .label = Sgrin Lawn
+    .accesskey = S
+
+## These menu items may use the same accesskey.
+
+# This should match reader-view-enter-button in browser.ftl
+menu-view-enter-readerview =
+    .label = Mynd i'r Golwg Darllen
+    .accesskey = D
+# This should match reader-view-close-button in browser.ftl
+menu-view-close-readerview =
+    .label = Cau'r Golwg Darllen
+    .accesskey = D
+
+##
+
+menu-view-show-all-tabs =
+    .label = Dangos Pob Tab
+    .accesskey = a
+menu-view-bidi-switch-page-direction =
+    .label = Newid Cyfeiriad Tudalen
+    .accesskey = N
+
+## History Menu
+
+menu-history =
+    .label = Hanes
+    .accesskey = H
+menu-history-show-all-history =
+    .label = Dangos yr Holl Hanes
+menu-history-clear-recent-history =
+    .label = Clirio Hanes Diweddar…
+menu-history-synced-tabs =
+    .label = Tabiau wedi'u Cydweddu
+menu-history-restore-last-session =
+    .label = Adfer y Sesiwn Flaenorol
+menu-history-hidden-tabs =
+    .label = Tabiau Cudd
+menu-history-undo-menu =
+    .label = Tabiau Wedi eu Cau'n Ddiweddar
+menu-history-undo-window-menu =
+    .label = Ffenestri wedi eu Cau yn Ddiweddar
+menu-history-reopen-all-tabs = Ailagor Pob Tab
+menu-history-reopen-all-windows = Ailagor Pob Ffenestr
+
+## Bookmarks Menu
+
+menu-bookmarks-menu =
+    .label = Nodau Tudalen
+    .accesskey = T
+menu-bookmarks-manage =
+    .label = Rheoli Nodau Tudalen
+menu-bookmark-current-tab =
+    .label = Gosod Nod Tudalen i'r Tab Cyfredol
+menu-bookmark-edit =
+    .label = Golygu'r Nod Tudalen
+menu-bookmark-tab =
+    .label = Gosod Nod Tudalen i'r Tab Cyfredol…
+menu-edit-bookmark =
+    .label = Golygu'r Nod Tudalen…
+menu-bookmarks-all-tabs =
+    .label = Nod Tudalen i Bob Tab…
+menu-bookmarks-toolbar =
+    .label = Bar Offer Nodau Tudalen
+menu-bookmarks-other =
+    .label = Nodau Tudalen Eraill
+menu-bookmarks-mobile =
+    .label = Nodau Tudalen Symudol
+
+## Tools Menu
+
+menu-tools =
+    .label = Offer
+    .accesskey = f
+menu-tools-downloads =
+    .label = Llwytho i Lawr
+    .accesskey = L
+menu-tools-addons-and-themes =
+    .label = Ychwanegion a Themâu
+    .accesskey = Y
+menu-tools-fxa-sign-in2 =
+    .label = Mewngofnodi
+    .accesskey = M
+menu-tools-turn-on-sync2 =
+    .label = Cychwyn Sync…
+    .accesskey = C
+menu-tools-sync-now =
+    .label = Cydweddu Nawr
+    .accesskey = y
+menu-tools-fxa-re-auth =
+    .label = Ailgysylltu â { -brand-product-name }…
+    .accesskey = A
+menu-tools-browser-tools =
+    .label = Offer Porwr
+    .accesskey = O
+menu-tools-task-manager =
+    .label = Rheolwr Tasgau
+    .accesskey = R
+menu-tools-page-source =
+    .label = Cod Gwreiddiol y Dudalen
+    .accesskey = o
+menu-tools-page-info =
+    .label = Gwybodaeth am y Dudalen
+    .accesskey = w
+menu-settings =
+    .label = Gosodiadau
+    .accesskey =
+        { PLATFORM() ->
+            [windows] G
+           *[other] d
+        }
+menu-tools-layout-debugger =
+    .label = Dadfygiwr Dyluniad
+    .accesskey = D
+
+## Window Menu
+
+menu-window-menu =
+    .label = Ffenestr
+menu-window-bring-all-to-front =
+    .label = Dwyn y Cyfan i'r Blaen
+
+## Help Menu
+
+
+# NOTE: For Engineers, any additions or changes to Help menu strings should
+# also be reflected in the related strings in appmenu.ftl. Those strings, by
+# convention, will have the same ID as these, but prefixed with "app".
+# Example: appmenu-get-help
+#
+# These strings are duplicated to allow for different casing depending on
+# where the strings appear.
+
+menu-help =
+    .label = Cymorth
+    .accesskey = C
+menu-get-help =
+    .label = Derbyn Cymorth
+    .accesskey = D
+menu-help-more-troubleshooting-info =
+    .label = Rhagor o Wybodaeth i Ddatrys Problemau
+    .accesskey = R
+menu-help-report-site-issue =
+    .label = Adrodd ar Fater Gwefan…
+menu-help-share-ideas =
+    .label = Rhannwch Syniadau ac Adborth…
+    .accesskey = R
+menu-help-enter-troubleshoot-mode2 =
+    .label = Y Modd Datrys Problemau…
+    .accesskey = M
+menu-help-exit-troubleshoot-mode =
+    .label = Diffodd y Modd Dartrys Problemau
+    .accesskey = D
+# Label of the Help menu item. Either this or
+# menu-help-notdeceptive is shown.
+menu-help-report-deceptive-site =
+    .label = Adroddwch ar wefan twyllodrus…
+    .accesskey = t
+menu-help-not-deceptive =
+    .label = Nid yw hon yn wefan twyllodrus…
+    .accesskey = t
diff --git a/l10n-cy/browser/browser/migration.ftl b/l10n-cy/browser/browser/migration.ftl
new file mode 100644
index 0000000000..efc76836a8
--- /dev/null
+++ b/l10n-cy/browser/browser/migration.ftl
@@ -0,0 +1,147 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+migration-wizard =
+    .title = Dewin Mewnforio
+import-from =
+    { PLATFORM() ->
+        [windows] Mewnforio Opsiynau, Nodau Tudalen, Hanes, Cyfrineiriau, a data arall o:
+       *[other] Mewnforio Dewisiadau, Nodau Tudalen, Hanes, Cyfrineiriau a data arall o:
+    }
+import-from-bookmarks = Mewnforio Nodau Tudalen o:
+import-from-ie =
+    .label = Microsoft Internet Explorer
+    .accesskey = M
+import-from-edge =
+    .label = Microsoft Edge
+    .accesskey = E
+import-from-edge-legacy =
+    .label = Yr Hen Microsoft Edge
+    .accesskey = H
+import-from-edge-beta =
+    .label = Microsoft Edge Beta
+    .accesskey = d
+import-from-nothing =
+    .label = Peidio mewnforio dim
+    .accesskey = d
+import-from-safari =
+    .label = Safari
+    .accesskey = S
+import-from-opera =
+    .label = Opera
+    .accesskey = O
+import-from-vivaldi =
+    .label = Vivaldi
+    .accesskey = V
+import-from-brave =
+    .label = Brave
+    .accesskey = r
+import-from-canary =
+    .label = Chrome Canary
+    .accesskey = n
+import-from-chrome =
+    .label = Chrome
+    .accesskey = C
+import-from-chrome-beta =
+    .label = Chrome Beta
+    .accesskey = B
+import-from-chrome-dev =
+    .label = Chrome Dev
+    .accesskey = D
+import-from-chromium =
+    .label = Chromium
+    .accesskey = u
+import-from-firefox =
+    .label = Firefox
+    .accesskey = x
+import-from-360se =
+    .label = 360 Porwr Diogel
+    .accesskey = 3
+import-from-opera-gx =
+    .label = Opera GX
+    .accesskey = O
+no-migration-sources = Methu canfod unrhyw rhaglenni sy'n cynnwys nodau tudalen, hanes na data cyfrineiriau.
+import-source-page-title = Gosodiadau Mewnforio a Data
+import-items-page-title = Eitemau i'w Mewnforio
+import-items-description = Dewis eitemau i'w mewnforio:
+import-permissions-page-title = Rhowch ganiatâd i { -brand-short-name }
+# Do not translate "Bookmarks.plist"; the file name is the same everywhere.
+import-permissions-description = Mae macOS yn gofyn i chi ganiatáu’n benodol i { -brand-short-name } gael mynediad at nodau tudalen Safari. Cliciwch “Continue” a dewiswch y ffeil “Bookmarks.plist” yn y panel File Open sy'n ymddangos.
+import-migrating-page-title = Mewnforio…
+import-migrating-description = Mae'r eitemau canlynol yn cael eu mewnforio…
+import-select-profile-page-title = Dewis Proffil
+import-select-profile-description = Mae'r proffiliau canlynol ar gael i'w mewnforio o:
+import-done-page-title = Wedi Cwblhau Mewnforio
+import-done-description = Cafodd yr eitemau canlynol eu mewnforio'n llwyddiannus:
+import-close-source-browser = Gwnewch yn siŵr fod y porwr wedi ei gau cyn parhau.
+source-name-ie = Internet Explorer
+source-name-edge = Microsoft Edge
+source-name-chrome = Google Chrome
+imported-safari-reading-list = Rhestr Darllen (O Safari)
+imported-edge-reading-list = Rhestr Darllen (O Edge)
+
+## Browser data types
+## All of these strings get a $browser variable passed in.
+## You can use the browser variable to differentiate the name of items,
+## which may have different labels in different browsers.
+## The supported values for the $browser variable are:
+## 360se
+## chrome
+## edge
+## firefox
+## ie
+## safari
+## The various beta and development versions of edge and chrome all get
+## normalized to just "edge" and "chrome" for these strings.
+
+browser-data-cookies-checkbox =
+    .label = Cwcis
+browser-data-cookies-label =
+    .value = Cwcis
+browser-data-history-checkbox =
+    .label =
+        { $browser ->
+            [firefox] Hanes Pori a Nodau Tudalen
+           *[other] Hanes Pori
+        }
+browser-data-history-label =
+    .value =
+        { $browser ->
+            [firefox] Hanes Pori a Nodau Tudalen
+           *[other] Hanes Pori
+        }
+browser-data-formdata-checkbox =
+    .label = Hanes Ffurflenni wedi'u Cadw
+browser-data-formdata-label =
+    .value = Hanes Ffurflenni wedi'u Cadw
+# This string should use the same phrase for "logins and passwords" as the
+# label in the main hamburger menu that opens about:logins.
+browser-data-passwords-checkbox =
+    .label = Mewngofnodion a Chyfrineiriau wedi'u Cadw
+# This string should use the same phrase for "logins and passwords" as the
+# label in the main hamburger menu that opens about:logins.
+browser-data-passwords-label =
+    .value = Mewngofnodion a Chyfrineiriau wedi'u Cadw
+browser-data-bookmarks-checkbox =
+    .label =
+        { $browser ->
+            [ie] Ffefrynnau
+            [edge] Ffefrynnau
+           *[other] Nodau Tudalen
+        }
+browser-data-bookmarks-label =
+    .value =
+        { $browser ->
+            [ie] Ffefrynnau
+            [edge] Ffefrynnau
+           *[other] Nodau Tudalen
+        }
+browser-data-otherdata-checkbox =
+    .label = Data Arall
+browser-data-otherdata-label =
+    .label = Data Arall
+browser-data-session-checkbox =
+    .label = Ffenestri a Thabiau
+browser-data-session-label =
+    .value = Ffenestri a Thabiau
diff --git a/l10n-cy/browser/browser/netError.ftl b/l10n-cy/browser/browser/netError.ftl
new file mode 100644
index 0000000000..0cd1ef9f5d
--- /dev/null
+++ b/l10n-cy/browser/browser/netError.ftl
@@ -0,0 +1,13 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+dns-not-found-title = Heb Ganfod Gweinydd
+# Variables:
+# $hostAndPath (String) - a suggested site (e.g. "www.example.com") that the user may have meant instead.
+dns-not-found-with-suggestion = Oeddech chi'n bwriadu mynd i <a data-l10n-name="website">{ $hostAndPath }</a>?
+dns-not-found-hint-header = <strong>Os ydych chi wedi rhoi'r cyfeiriad cywir, gallwch:</strong>
+dns-not-found-hint-try-again = Ceisiwch eto yn nes ymlaen
+dns-not-found-hint-check-network = Gwiriwch eich cysylltiad rhwydwaith
+dns-not-found-hint-firewall = Gwiriwch fod gan { -brand-short-name } ganiatâd i gael mynediad i'r we (efallai eich bod wedi'ch cysylltu ond tu ôl i fur cadarn)
diff --git a/l10n-cy/browser/browser/newtab/asrouter.ftl b/l10n-cy/browser/browser/newtab/asrouter.ftl
new file mode 100644
index 0000000000..5f12c2bd82
--- /dev/null
+++ b/l10n-cy/browser/browser/newtab/asrouter.ftl
@@ -0,0 +1,288 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+## These messages are used as headings in the recommendation doorhanger
+
+cfr-doorhanger-extension-heading = Estyniadau Cymeradwy
+cfr-doorhanger-feature-heading = Nodwedd Cymeradwy
+
+##
+
+cfr-doorhanger-extension-sumo-link =
+    .tooltiptext = Pam ydw i'n gweld hyn
+cfr-doorhanger-extension-cancel-button = Nid Nawr
+    .accesskey = N
+cfr-doorhanger-extension-ok-button = Ychwanegu Nawr
+    .accesskey = Y
+cfr-doorhanger-extension-manage-settings-button = Gosodiadau Argymell Rheoli
+    .accesskey = R
+cfr-doorhanger-extension-never-show-recommendation = Peidio Dangos yr Argymhelliad i Mi
+    .accesskey = P
+cfr-doorhanger-extension-learn-more-link = Dysgu rhagor
+# This string is used on a new line below the add-on name
+# Variables:
+#   $name (String) - Add-on author name
+cfr-doorhanger-extension-author = gan { $name }
+# This is a notification displayed in the address bar.
+# When clicked it opens a panel with a message for the user.
+cfr-doorhanger-extension-notification = Argymhelliad
+cfr-doorhanger-extension-notification2 = Argymhelliad
+    .tooltiptext = Argymhelliad Estyniad
+    .a11y-announcement = Mae argymhelliad estyniad ar gael
+# This is a notification displayed in the address bar.
+# When clicked it opens a panel with a message for the user.
+cfr-doorhanger-feature-notification = Argymhelliad
+    .tooltiptext = Argymhelliad Nodwedd
+    .a11y-announcement = Mae argymhelliad nodwedd ar gael
+
+## Add-on statistics
+## These strings are used to display the total number of
+## users and rating for an add-on. They are shown next to each other.
+
+# Variables:
+#   $total (Number) - The rating of the add-on from 1 to 5
+cfr-doorhanger-extension-rating =
+    .tooltiptext =
+        { $total ->
+            [zero] { $total } seren
+            [one] { $total } seren
+            [two] { $total } seren
+            [few] { $total } seren
+            [many] { $total } seren
+           *[other] { $total } seren
+        }
+# Variables:
+#   $total (Number) - The total number of users using the add-on
+cfr-doorhanger-extension-total-users =
+    { $total ->
+        [zero] { $total } defnyddiwr
+        [one] { $total } defnyddiwr
+        [two] { $total } ddefnyddiwr
+        [few] { $total } defnyddiwr
+        [many] { $total } defnyddiwr
+       *[other] { $total } defnyddiwr
+    }
+
+## Cookie Banner Handling Onboarding
+
+# Simplified version of the headline if the original text doesn't work
+# in your language: `See fewer cookie requests`.
+cfr-cookie-banner-handling-header = Gwaredu baneri cwcis!
+cfr-cookie-banner-handling-body = Caniatáu i { -brand-short-name } wrthod pob cais baner cwci yn awtomatig, pan fo modd. Fel arall, bydd pob cwci yn cael ei dderbyn i gau mwy fyth o faneri.
+cfr-cookie-banner-accept-button = Gwrthod Ceisiadau
+    .accesskey = G
+cfr-cookie-banner-reject-button = Nid Nawr
+    .accesskey = N
+cfr-cookie-banner-handling-header-variant-1 = Gweld llai o lamlenni cwcis
+cfr-cookie-banner-handling-body-variant-1 = Gadael i { -brand-short-name } ateb ffenestri llamlenni cwcis yn awtomatig er mwyn i chi fod yn rhydd i bori. Bydd { -brand-short-name } yn gwrthod pob cais os yn bosib, neu'n derbyn pob cais os nad.
+cfr-cookie-banner-accept-button-variant-1 = Cau Llamlenni
+    .accesskey = C
+cfr-cookie-banner-reject-button-variant-1 = Dim diolch
+    .accesskey = D
+cfr-cookie-banner-handling-header-variant-2 = Llai o Faneri Cwcis
+cfr-cookie-banner-handling-body-variant-2 = Caniatáu i { -brand-short-name } wrthod cais caniatâd cwci gwefan os yn bosibl neu dderbyn mynediad cwcis pan nad yw’n bosibl?
+cfr-cookie-banner-accept-button-variant-2 = Caniatáu
+    .accesskey = C
+cfr-cookie-banner-reject-button-variant-2 = Nid nawr
+    .accesskey = N
+
+## Firefox Accounts Message
+
+cfr-doorhanger-bookmark-fxa-header = Cydweddu eich nodau tudalen ym mhob man
+cfr-doorhanger-bookmark-fxa-body = Mae hwn yn dda! Peidiwch bod heb y nod tudalen hon ar eich dyfeisiau symudol. Dechrau arni gyda { -fxaccount-brand-name }.
+cfr-doorhanger-bookmark-fxa-link-text = Cydweddu nodau tudalen nawr…
+cfr-doorhanger-bookmark-fxa-close-btn-tooltip =
+    .aria-label = Cau botwm
+    .title = Cau
+
+## Protections panel
+
+cfr-protections-panel-header = Pori heb gael eich dilyn
+cfr-protections-panel-body = Cadwch eich data i chi'ch hun. Mae { -brand-short-name } yn eich diogelu rhag llawer o'r tracwyr mwyaf cyffredin sy'n eich dilyn ar-lein.
+cfr-protections-panel-link-text = Dysgu rhagor
+
+## What's New toolbar button and panel
+
+# This string is used by screen readers to offer a text based alternative for
+# the notification icon
+cfr-badge-reader-label-newfeature = Nodwedd newydd:
+cfr-whatsnew-button =
+    .label = Beth sy'n Newydd
+    .tooltiptext = Beth sy'n Newydd
+cfr-whatsnew-release-notes-link-text = Darllenwch y nodiadau rhyddhau
+
+## Enhanced Tracking Protection Milestones
+
+# Variables:
+#   $blockedCount (Number) - The total count of blocked trackers. This number will always be greater than 1.
+#   $date (Datetime) - The date we began recording the count of blocked trackers
+cfr-doorhanger-milestone-heading2 =
+    { $blockedCount ->
+        [zero] Mae { -brand-short-name } wedi rhwystro mwy na <b>{ $blockedCount }</b> o dracwyr ers { DATETIME($date, month: "long", year: "numeric") }!
+        [one] Mae { -brand-short-name } wedi rhwystro mwy nag <b>{ $blockedCount }</b> o dracwyr ers { DATETIME($date, month: "long", year: "numeric") }!
+        [two] Mae { -brand-short-name } wedi rhwystro mwy na <b>{ $blockedCount }</b> o dracwyr ers { DATETIME($date, month: "long", year: "numeric") }!
+        [few] Mae { -brand-short-name } wedi rhwystro mwy na <b>{ $blockedCount }</b> o dracwyr ers { DATETIME($date, month: "long", year: "numeric") }!
+        [many] Mae { -brand-short-name } wedi rhwystro mwy na <b>{ $blockedCount }</b> o dracwyr ers { DATETIME($date, month: "long", year: "numeric") }!
+       *[other] Mae { -brand-short-name } wedi rhwystro mwy na <b>{ $blockedCount }</b> o dracwyr ers { DATETIME($date, month: "long", year: "numeric") }!
+    }
+cfr-doorhanger-milestone-ok-button = Gweld y Cyfan
+    .accesskey = G
+cfr-doorhanger-milestone-close-button = Cau
+    .accesskey = C
+
+## DOH Message
+
+cfr-doorhanger-doh-body = Mae eich preifatrwydd yn bwysig. Mae { -brand-short-name } bellach yn cyfeirio eich ceisiadau DNS yn ddiogel pryd bynnag y bo modd at wasanaeth partner i'ch diogelu wrth i chi bori.
+cfr-doorhanger-doh-header = Chwilio DNS mwy diogel, wedi'u hamgryptio
+cfr-doorhanger-doh-primary-button-2 = Iawn
+    .accesskey = I
+cfr-doorhanger-doh-secondary-button = Analluogi
+    .accesskey = A
+
+## Fission Experiment Message
+
+cfr-doorhanger-fission-body-approved = Mae eich preifatrwydd yn bwysig. Erbyn hyn mae { -brand-short-name } yn ynysu, neu'n creu blychau tywod er mwyn cadw gwefannau oddi wrth ei gilydd, sy'n ei gwneud hi'n anoddach i hacwyr ddwyn cyfrineiriau, rhifau cardiau credyd, a manylion sensitif arall, oddi arnoch.
+cfr-doorhanger-fission-header = Ynysu Gwefan
+cfr-doorhanger-fission-primary-button = Iawn, Wedi deall!
+    .accesskey = I
+cfr-doorhanger-fission-secondary-button = Dysgu rhagor
+    .accesskey = D
+
+## Full Video Support CFR message
+
+cfr-doorhanger-video-support-body = Efallai na fydd fideos ar y wefan hon yn chwarae'n gywir ar y fersiwn hon o { -brand-short-name }. I gael cefnogaeth fideo lawn, diweddarwch { -brand-short-name } nawr.
+cfr-doorhanger-video-support-header = Diweddarwch { -brand-short-name } i chwarae fideo
+cfr-doorhanger-video-support-primary-button = Diweddarwch Nawr
+    .accesskey = D
+
+## Spotlight modal shared strings
+
+spotlight-learn-more-collapsed = Dysgu rhagor
+    .title = Ehangu i ddysgu rhagor am y nodwedd hon
+spotlight-learn-more-expanded = Dysgu rhagor
+    .title = Cau
+
+## VPN promotion dialog for public Wi-Fi users
+##
+## If a user is detected to be on a public Wi-Fi network, they are given a
+## bit of info about how to improve their privacy and then offered a button
+## to the Mozilla VPN page and a link to dismiss the dialog.
+
+# This header text can be explicitly wrapped.
+spotlight-public-wifi-vpn-header = Mae'n edrych fel eich bod chi'n defnyddio Wi-Fi cyhoeddus
+spotlight-public-wifi-vpn-body = I guddio'ch lleoliad a'ch gweithgaredd pori, ystyriwch Rwydwaith Preifat Rhithwir. Bydd yn helpu i'ch diogelu wrth bori mewn mannau cyhoeddus fel meysydd awyr a siopau coffi.
+spotlight-public-wifi-vpn-primary-button = Cadwch yn breifat gyda { -mozilla-vpn-brand-name }
+    .accesskey = b
+spotlight-public-wifi-vpn-link = Nid Nawr
+    .accesskey = N
+
+## Total Cookie Protection Rollout
+
+# "Test pilot" is used as a verb. Possible alternatives: "Be the first to try",
+# "Join an early experiment". This header text can be explicitly wrapped.
+spotlight-total-cookie-protection-header =
+    Rhowch brawf ar ein profiad
+    preifatrwydd mwyaf pwerus erioed
+spotlight-total-cookie-protection-body = Mae Total Cookie Protection yn atal tracwyr rhag defnyddio cwcis i'ch dilyn o amgylch y we.
+# "Early access" for this feature rollout means it's a "feature preview" or
+# "soft launch" as not everybody will get it yet.
+spotlight-total-cookie-protection-expanded = Mae { -brand-short-name } yn adeiladu ffens o amgylch cwcis, gan eu cyfyngu i'r wefan rydych chi arni fel na all tracwyr eu defnyddio i'ch dilyn chi. Gyda mynediad cynnar, byddwch yn helpu i wella'r nodwedd hon fel y gallwn barhau i adeiladu gwe well i bawb.
+spotlight-total-cookie-protection-primary-button = Cychwyn Total Cookie Protection
+spotlight-total-cookie-protection-secondary-button = Nid nawr
+
+## Emotive Continuous Onboarding
+
+spotlight-better-internet-header = Mae rhyngrwyd gwell yn dechrau gyda chi
+spotlight-better-internet-body = Pan fyddwch yn defnyddio { -brand-short-name }, rydych yn cefnogi rhyngrwyd agored a hygyrch sy'n well i bawb.
+spotlight-peace-mind-header = Rydyn ni yn eich cefnogi chi
+spotlight-peace-mind-body = Bob mis, ar gyfartaledd, mae { -brand-short-name } yn rhwystro dros 3,000 o dracwyr fesul defnyddiwr . Oherwydd dylai dim byd, yn enwedig niwsans preifatrwydd fel tracwyr, sefyll rhyngoch chi a'r rhyngrwyd da.
+spotlight-pin-primary-button =
+    { PLATFORM() ->
+        [macos] Cadw yn y Doc
+       *[other] Pinio i'r bar tasgau
+    }
+spotlight-pin-secondary-button = Nid nawr
+
+## MR2022 Background Update Windows native toast notification strings.
+##
+## These strings will be displayed by the Windows operating system in
+## a native toast, like:
+##
+## <b>multi-line title</b>
+## multi-line text
+## <img>
+## [ primary button ] [ secondary button ]
+##
+## The button labels are fitted into narrow fixed-width buttons by
+## Windows and therefore must be as narrow as possible.
+
+mr2022-background-update-toast-title = { -brand-short-name } newydd. Yn fwy preifat. Llai o dracwyr. Dim cyfaddawdu.
+mr2022-background-update-toast-text = Rhowch gynnig ar y { -brand-short-name } mwyaf newydd nawr, wedi'i uwchraddio gyda'n diogelwch gwrth-dracio cryfaf eto.
+# This button label will be fitted into a narrow fixed-width button by
+# Windows. Try to not exceed the width of the English text (compare it
+# using a variable font like Arial): the button can only fit 1-2
+# additional characters, exceeding characters will be truncated.
+mr2022-background-update-toast-primary-button-label = Agorwch { -brand-shorter-name } Nawr
+# This button label will be fitted into a narrow fixed-width button by
+# Windows. Try to not exceed the width of the English text (compare it using a
+# variable font like Arial): the button can only fit 1-2 additional characters,
+# exceeding characters will be truncated.
+mr2022-background-update-toast-secondary-button-label = Atgoffwch Fi Nes ymlaen
+
+## Firefox View CFR
+
+firefoxview-cfr-primarybutton = Rhowch gynnig arni
+    .accesskey = R
+firefoxview-cfr-secondarybutton = Nid nawr
+    .accesskey = N
+firefoxview-cfr-header-v2 = Ail gychwyn yn syth o'r lle roeddech chi
+firefoxview-cfr-body-v2 = Cael tabiau sydd wedi'u cau'n ddiweddar nôl, a symud yn rhwydd rhwng dyfeisiau gyda { -firefoxview-brand-name }.
+
+## Firefox View Spotlight
+
+firefoxview-spotlight-promo-title = Dywedwch helo wrth { -firefoxview-brand-name }
+# “Poof” refers to the expression to convey when something or someone suddenly disappears, or in this case, reappears. For example, “Poof, it’s gone.”
+firefoxview-spotlight-promo-subtitle = Eisiau'r tab agored hwnnw ar eich ffôn? Gafaelwch ynddo. Oes angen y wefan hon rydych newydd ymweld â hi? Pwff, mae'n ôl gyda { -firefoxview-brand-name }.
+firefoxview-spotlight-promo-primarybutton = Dyma sut mae'n gweithio...
+firefoxview-spotlight-promo-secondarybutton = Hepgor
+
+## Colorways expiry reminder CFR
+
+colorways-cfr-primarybutton = Dewis cyfuniad lliw
+    .accesskey = D
+# "shades" refers to the different color options available to users in colorways.
+colorways-cfr-body = Lliwiwch eich porwr gyda lliwiau unigryw { -brand-short-name } wedi'u hysbrydoli gan leisiau a newidiodd ddiwylliant.
+colorways-cfr-header-28days = Mae cyfuniadau lliw Lleisiau Annibynnol yn dod i ben Ionawr 16
+colorways-cfr-header-14days = Mae cyfuniadau lliw Lleisiau Annibynnol yn dod i ben mewn pythefnos
+colorways-cfr-header-7days = Mae cyfuniadau lliw Lleisiau Annibynnol yn dod i ben yr wythnos hon
+colorways-cfr-header-today = Mae cyfuniadau lliw Lleisiau Annibynnol yn dod i ben heddiw
+
+## Cookie Banner Handling CFR
+
+# Alternate headline for localization: "See fewer cookie requests"
+cfr-cookiebanner-header = Gwaredu baneri cwcis!
+cfr-cookiebanner-body = Caniatáu i { -brand-short-name } wrthod pob cais baner cwci yn awtomatig pan fo modd.
+cfr-cookiebanner-accept-button = Cau baneri
+    .accesskey = C
+cfr-cookiebanner-reject-button = Nid Nawr
+    .accesskey = N
+cfr-cookiebanner-header-variant-1 = Gweld llai o lamlenni cwcis
+cfr-cookiebanner-body-variant-1 = Gadael i { -brand-short-name } ateb ffenestri llamlenni cwcis yn awtomatig er mwyn i chi fod yn rhydd i bori. Bydd { -brand-short-name } yn gwrthod pob cais os yn bosib.
+cfr-cookiebanner-accept-button-variant-1 = Cau Llamlenni
+    .accesskey = L
+cfr-cookiebanner-reject-button-variant-1 = Dim Diolch
+    .accesskey = D
+cfr-cookiebanner-header-variant-2 = Llai o Faneri Cwcis
+cfr-cookiebanner-body-variant-2 = Lleihewch nifer y baneri cwci rydych yn eu gweld drwy ganiatáu i { -brand-short-name } wrthod cais caniatâd cwci gwefan os yw'n bosibl.
+cfr-cookiebanner-accept-button-variant-2 = Caniatáu
+    .accesskey = C
+cfr-cookiebanner-reject-button-variant-2 = Nid Nawr
+    .accesskey = N
+
+## These strings are used in the Fox doodle Pin/set default spotlights
+
+july-jam-headline = Rydyn ni yn eich cefnogi chi
+july-jam-body = Bob mis, mae { -brand-short-name } yn rhwystro 3,000+ o dracwyr fesul defnyddiwr ar gyfartaledd, gan roi mynediad diogel a chyflym i'r rhyngrwyd da i chi.
+july-jam-set-default-primary = Agor fy nolenni gyda { -brand-short-name }
diff --git a/l10n-cy/browser/browser/newtab/newtab.ftl b/l10n-cy/browser/browser/newtab/newtab.ftl
new file mode 100644
index 0000000000..6f1bc1b3e5
--- /dev/null
+++ b/l10n-cy/browser/browser/newtab/newtab.ftl
@@ -0,0 +1,287 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+### Firefox Home / New Tab strings for about:home / about:newtab.
+
+newtab-page-title = Tab Newydd
+newtab-settings-button =
+    .title = Cyfaddasu eich tudalen Tab Newydd
+newtab-personalize-icon-label =
+    .title = Personoli tab newydd
+    .aria-label = Personoli tab newydd
+newtab-personalize-dialog-label =
+    .aria-label = Personoli
+
+## Search box component.
+
+# "Search" is a verb/action
+newtab-search-box-search-button =
+    .title = Chwilio
+    .aria-label = Chwilio
+
+# Variables
+#  $engine (String): the name of the user's default search engine
+newtab-search-box-handoff-text = Chwilio gyda { $engine } neu roi cyfeiriad
+newtab-search-box-handoff-text-no-engine = Chwilio neu roi cyfeiriad
+# Variables
+#  $engine (String): the name of the user's default search engine
+newtab-search-box-handoff-input =
+    .placeholder = Chwilio gyda { $engine } neu roi cyfeiriad
+    .title = Chwilio gyda { $engine } neu roi cyfeiriad
+    .aria-label = Chwilio gyda { $engine } neu roi cyfeiriad
+newtab-search-box-handoff-input-no-engine =
+    .placeholder = Chwilio neu roi cyfeiriad
+    .title = Chwilio neu roi cyfeiriad
+    .aria-label = Chwilio neu roi cyfeiriad
+
+newtab-search-box-text = Chwilio'r we
+newtab-search-box-input =
+    .placeholder = Chwilio'r we
+    .aria-label = Chwilio'r we
+
+## Top Sites - General form dialog.
+
+newtab-topsites-add-search-engine-header = Ychwanegu Peiriant Chwilio
+newtab-topsites-add-shortcut-header = Llwybr Byr Newydd
+newtab-topsites-edit-topsites-header = Golygu'r Hoff Wefan
+newtab-topsites-edit-shortcut-header = Golygu Llwybr Byr
+newtab-topsites-title-label = Teitl
+newtab-topsites-title-input =
+    .placeholder = Rhoi teitl
+
+newtab-topsites-url-label = URL
+newtab-topsites-url-input =
+    .placeholder = Teipio neu ludo URL
+newtab-topsites-url-validation = Mae angen URL Ddilys
+
+newtab-topsites-image-url-label = URL Delwedd Gyfaddas
+newtab-topsites-use-image-link = Defnyddio delwedd gyfaddas…
+newtab-topsites-image-validation = Methodd y ddelwedd â llwytho. Defnyddiwch URL gwahanol.
+
+## Top Sites - General form dialog buttons. These are verbs/actions.
+
+newtab-topsites-cancel-button = Diddymu
+newtab-topsites-delete-history-button = Dileu o'r Hanes
+newtab-topsites-save-button = Cadw
+newtab-topsites-preview-button = Rhagolwg
+newtab-topsites-add-button = Ychwanegu
+
+## Top Sites - Delete history confirmation dialog.
+
+newtab-confirm-delete-history-p1 = Ydych chi'n siŵr eich bod chi am ddileu pob enghraifft o'r dudalen hon o'ch hanes?
+# "This action" refers to deleting a page from history.
+newtab-confirm-delete-history-p2 = Nid oes modd dadwneud hyn.
+
+## Top Sites - Sponsored label
+
+newtab-topsite-sponsored = Noddwyd
+
+## Context Menu - Action Tooltips.
+
+# General tooltip for context menus.
+newtab-menu-section-tooltip =
+    .title = Agor y ddewislen
+    .aria-label = Agor y ddewislen
+
+# Tooltip for dismiss button
+newtab-dismiss-button-tooltip =
+    .title = Tynnu
+    .aria-label = Tynnu
+
+# This tooltip is for the context menu of Pocket cards or Topsites
+# Variables:
+#  $title (String): The label or hostname of the site. This is for screen readers when the context menu button is focused/active.
+newtab-menu-content-tooltip =
+    .title = Agor y ddewislen
+    .aria-label = Agor dewislen cynnwys { $title }
+# Tooltip on an empty topsite box to open the New Top Site dialog.
+newtab-menu-topsites-placeholder-tooltip =
+    .title = Golygu'r wefan
+    .aria-label = Golygu'r wefan
+
+## Context Menu: These strings are displayed in a context menu and are meant as a call to action for a given page.
+
+newtab-menu-edit-topsites = Golygu
+newtab-menu-open-new-window = Agor Ffenestr Newydd
+newtab-menu-open-new-private-window = Agor mewn Ffenestr Preifat Newydd
+newtab-menu-dismiss = Cau
+newtab-menu-pin = Pinio
+newtab-menu-unpin = Dad-binio
+newtab-menu-delete-history = Dileu o'r Hanes
+newtab-menu-save-to-pocket = Cadw i { -pocket-brand-name }
+newtab-menu-delete-pocket = Dileu o { -pocket-brand-name }
+newtab-menu-archive-pocket = Archifo i { -pocket-brand-name }
+newtab-menu-show-privacy-info = Ein noddwyr a'ch preifatrwydd
+
+## Message displayed in a modal window to explain privacy and provide context for sponsored content.
+
+newtab-privacy-modal-button-done = Gorffen
+newtab-privacy-modal-button-manage = Rheoli gosodiadau cynnwys wedi'i noddi
+newtab-privacy-modal-header = Mae eich preifatrwydd yn bwysig.
+newtab-privacy-modal-paragraph-2 =
+    Yn ogystal â rhannu straeon cyfareddol, rydyn hefyd yn dangos i chi
+    gynnwys perthnasol wedi'i ddewis yn ofalus gan noddwyr dethol. Peidiwch â phoeni,
+    <strong>nid yw eich data pori byth yn gadael eich copi personol o { -brand-product-name }</strong> - nid ydym 
+    yn ei weld, na'n
+    noddwyr chwaith.
+newtab-privacy-modal-link = Dysgwch sut mae preifatrwydd yn gweithio ar y tab newydd
+
+##
+
+# Bookmark is a noun in this case, "Remove bookmark".
+newtab-menu-remove-bookmark = Tynnu Nod Tudalen
+# Bookmark is a verb here.
+newtab-menu-bookmark = Nod Tudalen
+
+## Context Menu - Downloaded Menu. "Download" in these cases is not a verb,
+## it is a noun. As in, "Copy the link that belongs to this downloaded item".
+
+newtab-menu-copy-download-link = Copïo Dolen Llwytho i Lawr
+newtab-menu-go-to-download-page = Mynd i'r Dudalen Llwytho i Lawr
+newtab-menu-remove-download = Tynnu o'r Hanes
+
+## Context Menu - Download Menu: These are platform specific strings found in the context menu of an item that has
+## been downloaded. The intention behind "this action" is that it will show where the downloaded file exists on the file
+## system for each operating system.
+
+newtab-menu-show-file =
+    { PLATFORM() ->
+        [macos] Dangos yn Finder
+       *[other] Agor Ffolder Cynhwysol
+    }
+newtab-menu-open-file = Agor Ffeil
+
+## Card Labels: These labels are associated to pages to give
+## context on how the element is related to the user, e.g. type indicates that
+## the page is bookmarked, or is currently open on another device.
+
+newtab-label-visited = Ymwelwyd
+newtab-label-bookmarked = Nod Tudalen
+newtab-label-removed-bookmark = Wedi Tynnu'r Nod Tudalen
+newtab-label-recommended = Trendio
+newtab-label-saved = Wedi ei gadw i { -pocket-brand-name }
+newtab-label-download = Wedi eu Llwytho i Lawr
+
+# This string is used in the story cards to indicate sponsored content
+# Variables:
+#  $sponsorOrSource (String): This is the name of a company or their domain
+newtab-label-sponsored = Noddir gan { $sponsorOrSource }
+
+# This string is used at the bottom of story cards to indicate sponsored content
+# Variables:
+#  $sponsor (String): This is the name of a sponsor
+newtab-label-sponsored-by = Noddir gan { $sponsor }
+
+# This string is used under the image of story cards to indicate source and time to read
+# Variables:
+#  $source (String): This is the name of a company or their domain
+#  $timeToRead (Number): This is the estimated number of minutes to read this story
+newtab-label-source-read-time = { $source } · { $timeToRead } mun
+
+## Section Menu: These strings are displayed in the section context menu and are
+## meant as a call to action for the given section.
+
+newtab-section-menu-remove-section = Tynnu'r Adran
+newtab-section-menu-collapse-section = Cau'r Adran
+newtab-section-menu-expand-section = Estyn yr Adran
+newtab-section-menu-manage-section = Rheoli'r Adran
+newtab-section-menu-manage-webext = Rheoli Estyniad
+newtab-section-menu-add-topsite = Ychwanegu Hoff Wefan
+newtab-section-menu-add-search-engine = Ychwanegu Peiriant Chwilio
+newtab-section-menu-move-up = Symud i Fyny
+newtab-section-menu-move-down = Symud i Lawr
+newtab-section-menu-privacy-notice = Hysbysiad Preifatrwydd
+
+## Section aria-labels
+
+newtab-section-collapse-section-label =
+    .aria-label = Cau'r Adran
+newtab-section-expand-section-label =
+    .aria-label = Ehangu'r Adran
+
+## Section Headers.
+
+newtab-section-header-topsites = Hoff Wefannau
+newtab-section-header-recent-activity = Gweithgaredd diweddar
+# Variables:
+#  $provider (String): Name of the corresponding content provider.
+newtab-section-header-pocket = Argymhellwyd gan { $provider }
+
+## Empty Section States: These show when there are no more items in a section. Ex. When there are no more Pocket story recommendations, in the space where there would have been stories, this is shown instead.
+
+newtab-empty-section-highlights = Cychwynnwch bori ac fe ddangoswn rhai erthyglau, fideos a thudalennau eraill difyr rydych wedi ymweld â nhw'n ddiweddar neu wedi gosod nod tudalen arnyn nhw yma.
+
+# Ex. When there are no more Pocket story recommendations, in the space where there would have been stories, this is shown instead.
+# Variables:
+#  $provider (String): Name of the content provider for this section, e.g "Pocket".
+newtab-empty-section-topstories = Rydych wedi dal i fynDewch nôl rhywbryd eto am fwy o'r straeon pwysicaf gan { $provider }. Methu aros? Dewiswch bwnc poblogaidd i ganfod straeon da o ar draws y we.
+
+## Empty Section (Content Discovery Experience). These show when there are no more stories or when some stories fail to load.
+
+newtab-discovery-empty-section-topstories-header = Wedi dal i fyny!
+newtab-discovery-empty-section-topstories-content = Dewch nôl eto am ragor o straeon.
+newtab-discovery-empty-section-topstories-try-again-button = Ceisiwch eto
+newtab-discovery-empty-section-topstories-loading = Llwytho…
+# Displays when a layout in a section took too long to fetch articles.
+newtab-discovery-empty-section-topstories-timed-out = Wps! Bron a lwytho'r adran hon, ond nid yn llwyr.
+
+## Pocket Content Section.
+
+# This is shown at the bottom of the trending stories section and precedes a list of links to popular topics.
+newtab-pocket-read-more = Pynciau Poblogaidd:
+newtab-pocket-new-topics-title = Am gael mwy fyth o straeon? Edrychwch ar y pynciau poblogaidd hyn gan { -pocket-brand-name }
+newtab-pocket-more-recommendations = Rhagor o Argymhellion
+newtab-pocket-learn-more = Dysgu rhagor
+newtab-pocket-cta-button = Defnyddio { -pocket-brand-name }
+newtab-pocket-cta-text = Cadw'r straeon rydych yn eu hoffi i { -pocket-brand-name } a bwydo'ch meddwl á deunydd diddorol.
+newtab-pocket-pocket-firefox-family = Mae { -pocket-brand-name } yn rhan o deulu { -brand-product-name }
+
+# A save to Pocket button that shows over the card thumbnail on hover.
+newtab-pocket-save-to-pocket = Cadw i { -pocket-brand-name }
+newtab-pocket-saved-to-pocket = Cadwyd i { -pocket-brand-name }
+
+# This is a button shown at the bottom of the Pocket section that loads more stories when clicked.
+newtab-pocket-load-more-stories-button = Llwytho rhagor o straeon
+
+## Pocket Final Card Section.
+## This is for the final card in the Pocket grid.
+
+newtab-pocket-last-card-title = Yn gyfredol nawr!
+newtab-pocket-last-card-desc = Dewch nôl eto am ragor o straeon.
+newtab-pocket-last-card-image =
+    .alt = Yn gyfredol nawr!
+
+# A save to Pocket button that shows over the card thumbnail on hover.
+newtab-pocket-save = Cadw
+newtab-pocket-saved = Wedi'u Cadw
+
+## Error Fallback Content.
+## This message and suggested action link are shown in each section of UI that fails to render.
+
+newtab-error-fallback-info = Wps, aeth rhywbeth o'i le wrth llwytho'r cynnwys hwn.
+newtab-error-fallback-refresh-link = Adnewyddu'r dudalen i geisio eto.
+
+## Customization Menu
+
+newtab-custom-shortcuts-title = Llwybrau Byr
+newtab-custom-shortcuts-subtitle = Gwefannau rydych yn eu cadw neu'n ymweld â nhw
+newtab-custom-row-selector =
+    { $num ->
+        [zero] { $num } rhesi
+        [one] { $num } rhes
+        [two] { $num } res
+        [few] { $num } rhes
+        [many] { $num } rhes
+       *[other] { $num } rhes
+    }
+newtab-custom-sponsored-sites = Llwybrau byr wedi'u noddi
+newtab-custom-pocket-title = Argymhellir gan  { -pocket-brand-name }
+newtab-custom-pocket-subtitle = Cynnwys eithriadol wedi'i guradu gan { -pocket-brand-name }, rhan o deulu { -brand-product-name }
+newtab-custom-pocket-sponsored = Straeon wedi'u noddi
+newtab-custom-pocket-show-recent-saves = Dangos pethau gadwyd yn ddiweddar
+newtab-custom-recent-title = Gweithgaredd diweddar
+newtab-custom-recent-subtitle = Detholiad o wefannau a chynnwys diweddar
+newtab-custom-close-button = Cau
+newtab-custom-settings = Rheoli rhagor o osodiadau
diff --git a/l10n-cy/browser/browser/newtab/onboarding.ftl b/l10n-cy/browser/browser/newtab/onboarding.ftl
new file mode 100644
index 0000000000..edbd08ca76
--- /dev/null
+++ b/l10n-cy/browser/browser/newtab/onboarding.ftl
@@ -0,0 +1,422 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+### UI strings for the MR1 onboarding / multistage about:welcome
+### Various strings use a non-breaking space to avoid a single dangling /
+### widowed word, so test on various window sizes if you also want this.
+
+
+## Welcome page strings
+
+onboarding-welcome-header = Croeso i { -brand-short-name }
+onboarding-start-browsing-button-label = Cychwyn Pori
+onboarding-not-now-button-label = Nid nawr
+
+## Custom Return To AMO onboarding strings
+
+return-to-amo-subtitle = Gwych, mae { -brand-short-name } gennych
+# <img data-l10n-name="icon"/> will be replaced with the icon belonging to the extension
+#
+# Variables:
+#   $addon-name (String) - Name of the add-on
+return-to-amo-addon-title = Nawr gadewch i ni gael <img data-l10n-name="icon"/> <b>{ $addon-name }</b> i chi.
+return-to-amo-add-extension-label = Ychwanegwch yr Estyniad
+return-to-amo-add-theme-label = Ychwanegu'r Thema
+
+##  Variables: $addon-name (String) - Name of the add-on to be installed
+
+mr1-return-to-amo-subtitle = Dywedwch helo wrth { -brand-short-name }
+mr1-return-to-amo-addon-title = Mae gennych chi borwr cyflym a phreifat ar flaenau eich bysedd. Nawr gallwch chi ychwanegu <b>{ $addon-name }</b> a gwneud mwy fyth gyda { -brand-short-name }.
+mr1-return-to-amo-add-extension-label = Ychwanegu { $addon-name }
+
+## Multistage onboarding strings (about:welcome pages)
+
+# Aria-label to make the "steps" of multistage onboarding visible to screen readers.
+# Variables:
+#   $current (Int) - Number of the current page
+#   $total (Int) - Total number of pages
+onboarding-welcome-steps-indicator =
+    .aria-label = Cychwyn arni: sgrin { $current } o { $total }
+
+# Aria-label to make the "steps" of multistage onboarding visible to screen readers.
+# Variables:
+#   $current (Int) - Number of the current page
+#   $total (Int) - Total number of pages
+
+onboarding-welcome-steps-indicator2 =
+    .aria-valuetext = Cynnydd: cam { $current } o { $total }
+onboarding-welcome-steps-indicator-label =
+    .aria-label = Cynnydd: cam { $current } o { $total }
+# "Hero Text" displayed on left side of welcome screen.
+# The "Fire" in "Fire starts here" plays on the "Fire" in "Firefox".
+# It also signals the passion users bring to Firefox, how they use
+# Firefox to pursue those passions, as well as the boldness in their
+# choice to use Firefox over a larger competitor browser.
+# An alternative title for localization is: "It starts here".
+# This text can be formatted to span multiple lines as needed.
+mr1-welcome-screen-hero-text = Mae'n cychwyn yma
+# Caption for background image in about:welcome. "Soraya Osorio" is the name
+# of the person and shouldn't be translated.
+# In case your language needs to adapt the nouns to a gender, Soraya is a female name (she/her).
+# You can see the picture in about:welcome in Nightly 90.
+mr1-onboarding-welcome-image-caption = Soraya Osorio - Dylunydd dodrefn, cefnogwr Firefox
+# This button will open system settings to turn on prefers-reduced-motion
+mr1-onboarding-reduce-motion-button-label = Diffodd animeiddiadau
+
+## Title and primary button strings differ between platforms as they
+## match the OS' application context menu item action where Windows uses "pin"
+## and "taskbar" while macOS "keep" and "Dock" (proper noun).
+
+# Title used on welcome page when Firefox is not pinned
+mr1-onboarding-pin-header =
+    { PLATFORM() ->
+        [macos] Cadwch { -brand-short-name } yn eich Doc ar gyfer mynediad hawdd
+       *[other] Piniwch { -brand-short-name } i'ch bar tasgau ar gyfer mynediad hawdd
+    }
+# Primary button string used on welcome page when Firefox is not pinned.
+mr1-onboarding-pin-primary-button-label =
+    { PLATFORM() ->
+        [macos] Cadw yn y Doc
+       *[other] Pinio i'r bar tasgau
+    }
+
+## Multistage MR1 onboarding strings (about:welcome pages)
+
+# This string will be used on welcome page primary button label
+# when Firefox is both pinned and default
+mr1-onboarding-get-started-primary-button-label = Cychwyn arni
+mr1-onboarding-welcome-header = Croeso i { -brand-short-name }
+mr1-onboarding-set-default-pin-primary-button-label = Gwneud { -brand-short-name } fy mrhif borwr
+    .title = Yn gosod { -brand-short-name } fel y porwr rhagosodedig a'i binio i'r bar tasgau
+# This string will be used on welcome page primary button label
+# when Firefox is not default but already pinned
+mr1-onboarding-set-default-only-primary-button-label = Gwneud { -brand-short-name } fy mhorwr rhagosodedig
+mr1-onboarding-set-default-secondary-button-label = Nid nawr
+mr1-onboarding-sign-in-button-label = Mewngofnodi
+
+## Title, subtitle and primary button string used on set default onboarding screen
+## when Firefox is not default browser
+
+mr1-onboarding-default-header = Gwneud { -brand-short-name } eich prif borwr?
+mr1-onboarding-default-subtitle = Rhowch gyflymder, diogelwch a phreifatrwydd ar awtobeilot.
+mr1-onboarding-default-primary-button-label = Ei wneud eich prif borwr
+
+## Multistage MR1 onboarding strings (about:welcome pages)
+
+mr1-onboarding-import-header = Dewch â'r cyfan gyda chi
+mr1-onboarding-import-subtitle = Mewnforio'ch cyfrineiriau, <br/>nodau tudalen a rhagor.
+# The primary import button label will depend on whether we can detect which browser was used to download Firefox.
+# Variables:
+#   $previous (Str) - Previous browser name, such as Edge, Chrome
+mr1-onboarding-import-primary-button-label-attribution = Mewnforio o { $previous }
+# This string will be used in cases where we can't detect the previous browser name.
+mr1-onboarding-import-primary-button-label-no-attribution = Mewnforio o'r porwr blaenorol
+mr1-onboarding-import-secondary-button-label = Nid nawr
+mr2-onboarding-colorway-header = Bywyd mewn lliw
+mr2-onboarding-colorway-subtitle = Cyfuniadau lliw newydd bywiog. Ar gael am gyfnod cyfyngedig.
+mr2-onboarding-colorway-primary-button-label = Cadw'r cyfuniad lliw
+mr2-onboarding-colorway-secondary-button-label = Nid nawr
+mr2-onboarding-colorway-label-soft = Meddal
+mr2-onboarding-colorway-label-balanced = Cytbwys
+# "Bold" is used in the sense of bravery or courage, not in the sense of
+# emphasized text.
+mr2-onboarding-colorway-label-bold = Beiddgar
+# Automatic theme uses operating system color settings
+mr2-onboarding-theme-label-auto = Awto
+# This string will be used for Default theme
+mr2-onboarding-theme-label-default = Rhagosodedig
+mr1-onboarding-theme-header = Ei wneud eich un chi
+mr1-onboarding-theme-subtitle = Personoli { -brand-short-name } gyda thema.
+mr1-onboarding-theme-primary-button-label = Cadw'r thema
+mr1-onboarding-theme-secondary-button-label = Nid nawr
+# System theme uses operating system color settings
+mr1-onboarding-theme-label-system = Thema'r system
+mr1-onboarding-theme-label-light = Golau
+mr1-onboarding-theme-label-dark = Tywyll
+# "Alpenglow" here is the name of the theme, and should be kept in English.
+mr1-onboarding-theme-label-alpenglow = Alpenglow
+onboarding-theme-primary-button-label = Gorffen
+
+## Please make sure to split the content of the title attribute into lines whose
+## width corresponds to about 40 Latin characters, to ensure that the tooltip
+## doesn't become too long. Line breaks will be preserved when displaying the
+## tooltip.
+
+# Tooltip displayed on hover of system theme
+mr1-onboarding-theme-tooltip-system =
+    .title =
+        Dilyn thema'r system weithredu
+        ar gyfer botymau, bwydlenni, a ffenestri.
+# Input description for system theme
+mr1-onboarding-theme-description-system =
+    .aria-description =
+        Dilyn thema'r system weithredu
+        ar gyfer botymau, bwydlenni, a ffenestri.
+# Tooltip displayed on hover of light theme
+mr1-onboarding-theme-tooltip-light =
+    .title =
+        Defnyddio thema olau ar gyfer botymau,
+        dewislenni a ffenestri.
+# Input description for light theme
+mr1-onboarding-theme-description-light =
+    .aria-description =
+        Defnyddio thema olau ar gyfer botymau,
+        dewislenni a ffenestri.
+# Tooltip displayed on hover of dark theme
+mr1-onboarding-theme-tooltip-dark =
+    .title =
+        Defnyddio thema dywyll ar gyfer botymau,
+        dewislenni a ffenestri.
+# Input description for dark theme
+mr1-onboarding-theme-description-dark =
+    .aria-description =
+        Defnyddio thema dywyll ar gyfer botymau,
+        dewislenni a ffenestri.
+# Tooltip displayed on hover of Alpenglow theme
+mr1-onboarding-theme-tooltip-alpenglow =
+    .title =
+        Defnyddio thema ddeinamig, lliwgar ar gyfer botymau,
+        dewislenni a ffenestri.
+# Input description for Alpenglow theme
+mr1-onboarding-theme-description-alpenglow =
+    .aria-description =
+        Defnyddio thema ddeinamig, lliwgar ar gyfer botymau,
+        dewislenn a ffenestri.
+# Tooltip displayed on hover of non-default colorway theme
+# variations e.g. soft, balanced, bold
+mr2-onboarding-theme-tooltip =
+    .title = Defnyddio'r cyfuniad lliw hwn.
+# Selector description for non-default colorway theme
+# variations e.g. soft, balanced, bold
+mr2-onboarding-theme-description =
+    .aria-description = Defnyddio'r cyfuniad lliw yma.
+# Tooltip displayed on hover of colorway
+# Variables:
+#   $colorwayName (String) - Name of colorway
+mr2-onboarding-colorway-tooltip =
+    .title = Archwilio cyfuniadau lliw { $colorwayName }
+# Selector description for colorway
+# Variables:
+#   $colorwayName (String) - Name of colorway
+mr2-onboarding-colorway-label = Archwilio cyfuniadau lliw { $colorwayName }
+# Tooltip displayed on hover of default themes
+mr2-onboarding-default-theme-tooltip =
+    .title = Archwilio themâu rhagosodedig.
+# Selector description for default themes
+mr2-onboarding-default-theme-label = Archwilio themâu rhagosodedig.
+
+## Strings for Thank You page
+
+mr2-onboarding-thank-you-header = Diolch am ein dewis ni
+mr2-onboarding-thank-you-text = Mae { -brand-short-name } yn borwr annibynnol gyda chefnogaeth corff dim-er-elw. Gyda'n gilydd, rydyn ni'n gwneud y we yn ddiogelach, iachach a mwy preifat.
+mr2-onboarding-start-browsing-button-label = Cychwyn pori
+
+## Multistage live language reloading onboarding strings (about:welcome pages)
+##
+## The following language names are generated by the browser's Intl.DisplayNames API.
+##
+## Variables:
+##   $negotiatedLanguage (String) - The name of the langpack's language, e.g. "Español (ES)"
+
+
+## Multistage live language reloading onboarding strings (about:welcome pages)
+##
+## The following language names are generated by the browser's Intl.DisplayNames API.
+##
+## Variables:
+##   $negotiatedLanguage (String) - The name of the langpack's language, e.g. "Español (ES)"
+##   $systemLanguage (String) - The name of the system language, e.g "Español (ES)"
+##   $appLanguage (String) - The name of the language shipping in the browser build, e.g. "English (EN)"
+
+onboarding-live-language-header = Dewiswch Eich Iaith
+mr2022-onboarding-live-language-text = Mae { -brand-short-name } yn siarad eich iaith
+mr2022-language-mismatch-subtitle = Diolch i'n cymuned, mae { -brand-short-name } yn cael ei gyfieithu i dros 90 o ieithoedd. Mae'n edrych fel bod eich system yn defnyddio { $systemLanguage } , ac mae { -brand-short-name } yn defnyddio { $appLanguage }.
+onboarding-live-language-button-label-downloading = Wrthi'n llwytho i lawr y pecyn iaith ar gyfer { $negotiatedLanguage }…
+onboarding-live-language-waiting-button = Yn cael manylion yr ieithoedd sydd ar gael…
+onboarding-live-language-installing = Wrthi'n gosod y pecyn iaith ar gyfer { $negotiatedLanguage }…
+mr2022-onboarding-live-language-switch-to = Newid i { $negotiatedLanguage }
+mr2022-onboarding-live-language-continue-in = Parhau yn { $appLanguage }
+onboarding-live-language-secondary-cancel-download = Diddymu
+onboarding-live-language-skip-button-label = Hepgor
+
+## Firefox 100 Thank You screens
+
+# "Hero Text" displayed on left side of welcome screen. This text can be
+# formatted to span multiple lines as needed. The <span data-l10n-name="zap">
+# </span> in this string allows a "zap" underline style to be automatically
+# added to the text inside it. "Yous" should stay inside the zap span, but
+# "Thank" can be put inside instead if there's no "you" in the translation.
+# The English text would normally be "100 Thank-Yous" i.e., plural noun, but for
+# aesthetics of splitting it across multiple lines, the hyphen is omitted.
+fx100-thank-you-hero-text =
+    100
+    Mil
+    <span data-l10n-name="zap">Diolch</span>
+fx100-thank-you-subtitle = Dyma ein 100fed fersiwn! Diolch am ein helpu i adeiladu rhyngrwyd gwell ac iachach.
+fx100-thank-you-pin-primary-button-label =
+    { PLATFORM() ->
+        [macos] Cadw { -brand-short-name } yn y Doc
+       *[other] Pinio { -brand-short-name } i'r bar tasgau
+    }
+fx100-upgrade-thanks-header = 100 Mil Diolch
+# Message shown with a start-browsing button. Emphasis <em> should be for "you"
+# but "Thank" can be used instead if there's no "you" in the translation.
+fx100-upgrade-thank-you-body = Dyma ein 100fed fersiwn o { -brand-short-name }. Diolch i <em>chi</em> am ein helpu i adeiladu rhyngrwyd gwell ac iachach.
+# Message shown with either a pin-to-taskbar or set-default button.
+fx100-upgrade-thanks-keep-body = Dyma ein 100fed fersiwn! Diolch am fod yn rhan o'n cymuned. Cadwch { -brand-short-name } wrth law am y 100 nesaf.
+mr2022-onboarding-secondary-skip-button-label = Hepgor y cam hwn
+
+## MR2022 New User Pin Firefox screen strings
+
+# Title used on about:welcome for new users when Firefox is not pinned.
+# In this context, open up is synonymous with "Discover".
+# The metaphor is that when they open their Firefox browser, it helps them discover an amazing internet.
+# If this translation does not make sense in your language, feel free to use the word "discover."
+mr2022-onboarding-welcome-pin-header = Darganfod rhyngrwyd anhygoel
+# Subtitle is used on onboarding page for new users page when Firefox is not pinned
+mr2022-onboarding-welcome-pin-subtitle = Agorwch { -brand-short-name } o unrhyw le gydag un clic. Bob tro y gwnewch chi, rydych chi'n dewis gwe fwy agored ac annibynnol.
+# Primary button string used on welcome page for when Firefox is not pinned.
+mr2022-onboarding-pin-primary-button-label =
+    { PLATFORM() ->
+        [macos] Cadw { -brand-short-name } yn y Doc
+       *[other] Pinio { -brand-short-name } i'r bar tasgau
+    }
+# Subtitle will be used when user already has Firefox pinned, but
+# has not set it as their default browser.
+# When translating "zip", please feel free to pick a verb that signifies movement and/or exploration
+# and makes sense in the context of navigating the web.
+mr2022-onboarding-set-default-only-subtitle = Dechreuwch gyda phorwr sy'n cael ei gefnogi gan gorff dim-er-elw. Rydym yn diogelu eich preifatrwydd tra byddwch yn teithio o gwmpas y we.
+
+## MR2022 Existing User Pin Firefox Screen Strings
+
+# Title used on multistage onboarding page for existing users when Firefox is not pinned
+mr2022-onboarding-existing-pin-header = Diolch am garu { -brand-product-name }
+# Subtitle is used on onboarding page for existing users when Firefox is not pinned
+mr2022-onboarding-existing-pin-subtitle = Agorwch ryngrwyd iachach o unrhyw le gydag un clic. Mae ein diweddariad diweddaraf yn llawn o bethau newydd rydyn ni'n meddwl y byddwch chi'n eu caru.
+# Subtitle will be used on the welcome screen for existing users
+# when they already have Firefox pinned but not set as default
+mr2022-onboarding-existing-set-default-only-subtitle = Defnyddiwch borwr sy'n diogelu eich preifatrwydd tra byddwch chi'n teithio o gwmpas y we. Mae ein diweddariad diweddaraf yn llawn o bethau rydych chi'n eu caru.
+mr2022-onboarding-existing-pin-checkbox-label = Hefyd, ychwanegu pori preifat { -brand-short-name }
+
+## MR2022 New User Set Default screen strings
+
+# This string is the title used when the user already has pinned the browser, but has not set default.
+mr2022-onboarding-set-default-title = Gwnewch { -brand-short-name } eich hoff borwr
+mr2022-onboarding-set-default-primary-button-label = Gosod { -brand-short-name } fel eich porwr rhagosodedig
+# When translating "zip", please feel free to pick a verb that signifies movement and/or exploration
+# and makes sense in the context of navigating the web.
+mr2022-onboarding-set-default-subtitle = Defnyddiwch borwr sy'n cael ei gefnogi gan gorff dim-er-elw. Rydym yn diogelu eich preifatrwydd tra byddwch yn teithio o amgylch y we.
+
+## MR2022 Get Started screen strings.
+## These strings will be used on the welcome page
+## when Firefox is already set to default and pinned.
+
+# When translating "zip", please feel free to pick a verb that signifies movement and/or exploration
+# and makes sense in the context of navigating the web.
+mr2022-onboarding-get-started-primary-subtitle = Mae ein fersiwn diweddaraf wedi'i adeiladu o'ch cwmpas chi, gan ei gwneud hi'n haws nag erioed i deithio o amgylch y we. Mae'n llawn o nodweddion rydyn ni'n meddwl y byddwch chi'n eu caru.
+mr2022-onboarding-get-started-primary-button-label = Ei osod mewn eiliadau
+
+## MR2022 Import Settings screen strings
+
+mr2022-onboarding-import-header = Gosodiad chwim
+mr2022-onboarding-import-subtitle = Gosodwch { -brand-short-name } fel rydych chi'n ei hoffi. Ychwanegwch eich nodau tudalen, cyfrineiriau, a mwy o'ch hen borwr.
+mr2022-onboarding-import-primary-button-label-no-attribution = Mewnforiwch o'ch porwr blaenorol
+
+## If your language uses grammatical genders, in the description for the
+## colorway feel free to switch from "You are a X. You…" (e.g. "You are a
+## Playmaker. You create…") to "X: you…" ("Playmaker: You create…"). This might
+## help creating a more inclusive translation.
+
+mr2022-onboarding-colorway-title = Dewiswch y lliw sy'n eich ysbrydoli
+mr2022-onboarding-colorway-subtitle = Gall lleisiau annibynnol newid diwylliant.
+mr2022-onboarding-colorway-primary-button-label-continue = Gosod a pharhau
+mr2022-onboarding-existing-colorway-checkbox-label = Gwnewch { -firefox-home-brand-name } yn gartref liwgar i chi
+mr2022-onboarding-colorway-label-default = Rhagosodiad
+mr2022-onboarding-colorway-tooltip-default2 =
+    .title = Lliwiau cyfredol { -brand-short-name }
+mr2022-onboarding-colorway-description-default = <b>Defnyddio fy lliwiau { -brand-short-name } cyfredol.</b>
+mr2022-onboarding-colorway-label-playmaker = Arweinydd
+mr2022-onboarding-colorway-tooltip-playmaker2 =
+    .title = Crëwr (coch)
+mr2022-onboarding-colorway-description-playmaker = <b>Rydych chi'n Arweinydd.</b> Rydych chi'n creu cyfleoedd i ennill a helpu pawb o'ch cwmpas i ddyrchafu eu gêm.
+mr2022-onboarding-colorway-label-expressionist = Mynegiadwr
+mr2022-onboarding-colorway-tooltip-expressionist2 =
+    .title = Mynegiadwr (melyn)
+mr2022-onboarding-colorway-description-expressionist = <b>Ydych chi'n Fynegiadwr.</b> Rydych chi'n gweld y byd yn wahanol ac mae eich creadigaethau'n cyffroi emosiynau pobl eraill.
+mr2022-onboarding-colorway-label-visionary = Gweledydd
+mr2022-onboarding-colorway-tooltip-visionary2 =
+    .title = Gweledydd (gwyrdd)
+mr2022-onboarding-colorway-description-visionary = <b>Rydych chi'n Weledydd.</b> Rydych chi'n cwestiynu'r status quo ac yn symud eraill i ddychmygu dyfodol gwell.
+mr2022-onboarding-colorway-label-activist = Ymgyrchydd
+mr2022-onboarding-colorway-tooltip-activist2 =
+    .title = Ymgyrchydd (glas)
+mr2022-onboarding-colorway-description-activist = <b>Rydych chi'n Ymgyrchydd.</b> Rydych yn gadael y byd yn lle gwell nag y daethoch iddo ac yn arwain eraill i gredu.
+mr2022-onboarding-colorway-label-dreamer = Breuddwydiwr
+mr2022-onboarding-colorway-tooltip-dreamer2 =
+    .title = Breuddwydiwr (porffor)
+mr2022-onboarding-colorway-description-dreamer = <b>Rydych chi'n Freuddwydiwr.</b> Rydych chi'n credu bod ffortiwn yn ffafrio'r beiddgar ac yn ysbrydoli eraill i fod yn ddewr.
+mr2022-onboarding-colorway-label-innovator = Arloesydd
+mr2022-onboarding-colorway-tooltip-innovator2 =
+    .title = Arloesydd (oren)
+mr2022-onboarding-colorway-description-innovator = <b>Rydych chi'n Arloesydd.</b> Rydych chi'n gweld cyfleoedd ym mhobman ac yn cael effaith ar fywydau pawb o'ch cwmpas.
+
+## MR2022 Multistage Mobile Download screen strings
+
+mr2022-onboarding-mobile-download-title = Neidiwch o'r gliniadur i'r ffôn ac yn ôl eto
+mr2022-onboarding-mobile-download-subtitle = Cipiwch dabiau o un ddyfais a pharhau o le gwnaethoch chi ei adael ar ddyfais arall. Hefyd cydweddwch eich nodau tudalen a'ch cyfrineiriau lle bynnag rydych chi'n defnyddio { -brand-product-name }.
+mr2022-onboarding-mobile-download-cta-text = Sganiwch y cod QR i gael { -brand-product-name } ar gyfer ffôn symudol neu <a data-l10n-name="download-label">anfon dolen llwytho i chi'ch hun.</a>
+mr2022-onboarding-no-mobile-download-cta-text = Sganiwch y cod QR i gael { -brand-product-name } ar gyfer ffôn symudol.
+
+## MR2022 Upgrade Dialog screens
+## Pin private window screen shown only for users who don't have Firefox private pinned
+
+mr2022-upgrade-onboarding-pin-private-window-header = Cael rhyddid pori preifat gydag un clic
+mr2022-upgrade-onboarding-pin-private-window-subtitle = Dim cwcis na hanes wedi'u cadw, o'ch bwrdd gwaith. Porwch fel nad oes neb yn gwylio.
+mr2022-upgrade-onboarding-pin-private-window-primary-button-label =
+    { PLATFORM() ->
+        [macos] Cadw bori preifat { -brand-short-name } yn y Doc
+       *[other] Pinio pori preifat { -brand-short-name } i'r bar tasgau
+    }
+
+## MR2022 Privacy Segmentation screen strings
+
+mr2022-onboarding-privacy-segmentation-title = Rydym wastad yn parchu eich preifatrwydd
+mr2022-onboarding-privacy-segmentation-subtitle = O awgrymiadau deallus i chwilio clyfrach, rydym yn gweithio'n gyson i greu { -brand-product-name } gwell, mwy personol.
+mr2022-onboarding-privacy-segmentation-text-cta = Beth hoffech chi ei weld pan fyddwn yn cynnig nodweddion newydd sy'n defnyddio'ch data i gyfoethogi eich pori?
+mr2022-onboarding-privacy-segmentation-button-primary-label = Defnyddio argymhellion { -brand-product-name }
+mr2022-onboarding-privacy-segmentation-button-secondary-label = Dangos gwybodaeth fanwl
+
+## MR2022 Multistage Gratitude screen strings
+
+mr2022-onboarding-gratitude-title = Rydych chi'n ein helpu ni i adeiladu gwe well.
+mr2022-onboarding-gratitude-subtitle = Diolch am ddefnyddio { -brand-short-name }, gyda chefnogaeth y Mozilla Foundation. Gyda'ch cefnogaeth chi, rydyn ni'n gweithio i wneud y rhyngrwyd yn fwy agored, hygyrch, ac yn well i bawb.
+mr2022-onboarding-gratitude-primary-button-label = Gweld beth sy'n newydd
+mr2022-onboarding-gratitude-secondary-button-label = Cychwyn pori
+
+## Onboarding spotlight for infrequent users
+
+onboarding-infrequent-import-title = Gwnewch eich hun yn gartrefol
+onboarding-infrequent-import-subtitle = P'un ai rydych yn ymgartrefu neu'n galw heibio, cofiwch y gallwch chi fewnforio eich nodau tudalen, cyfrineiriau a mwy.
+onboarding-infrequent-import-primary-button = Mewnforio i { -brand-short-name }
+
+## MR2022 Illustration alt tags
+## Descriptive tags for illustrations used by screen readers and other assistive tech
+
+mr2022-onboarding-pin-image-alt =
+    .aria-label = Person yn gweithio ar liniadur wedi'i amgylchynu gan sêr a blodau
+mr2022-onboarding-default-image-alt =
+    .aria-label = Person yn cofleidio logo { -brand-product-name }
+mr2022-onboarding-import-image-alt =
+    .aria-label = Person yn reidio bwrdd sgrialu gyda blwch o eiconau meddalwedd
+mr2022-onboarding-mobile-download-image-alt =
+    .aria-label = Brogaod yn hercian ar draws padiau lili gyda chod QR er mwyn llwytho { -brand-product-name } ar gyfer ffôn symudol yn y canol
+mr2022-onboarding-pin-private-image-alt =
+    .aria-label = Mae hudlath yn gwneud i logo pori preifat { -brand-product-name } ymddangos allan o het
+mr2022-onboarding-privacy-segmentation-image-alt =
+    .aria-label = Pawen lawen dwylo â chroen golau a chroen tywyll
+mr2022-onboarding-gratitude-image-alt =
+    .aria-label = Golygfa o fachlud trwy ffenestr gyda llwynog a phlanhigyn tŷ ar silff ffenestr
+mr2022-onboarding-colorways-image-alt =
+    .aria-label = Mae llaw gyda chwistrell yn paentio collage lliwgar o lygad gwyrdd, esgid oren, pêl-fasged goch, clustffonau porffor, calon las a choron felen
diff --git a/l10n-cy/browser/browser/nsserrors.ftl b/l10n-cy/browser/browser/nsserrors.ftl
new file mode 100644
index 0000000000..f27480e0c4
--- /dev/null
+++ b/l10n-cy/browser/browser/nsserrors.ftl
@@ -0,0 +1,354 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# DO NOT ADD THINGS OTHER THAN ERROR MESSAGES HERE.
+# This file gets parsed into a JS dictionary of all known error message ids in
+# gen_aboutneterror_codes.py . If we end up needing fluent attributes or
+# refactoring them in some way, the script will need updating.
+
+# Variables:
+# $hostname (String) - Hostname of the website with SSL error.
+# $errorMessage (String) - Error message corresponding to the type of error we are experiencing.
+ssl-connection-error = Digwyddodd gwall wrth gysylltu â { $hostname }. { $errorMessage }
+
+# Variables:
+# $error (string) - NSS error code string that specifies type of cert error. e.g. unknown issuer, invalid cert, etc.
+cert-error-code-prefix = Cod gwall: { $error }
+
+psmerr-ssl-disabled = Methu cysylltu'n ddiogel oherwydd bod y protocol SSL wedi ei analluogi.
+psmerr-ssl2-disabled = Methu cysylltu'n ddiogel oherwydd bod y wefan'n defnyddio hen fersiwn anniogel o brotocol SSL.
+
+# This is a multi-line message.
+psmerr-hostreusedissuerandserial =
+    Rydych wedi derbyn tystysgrif annilys.  Cysylltwch gweinyddwr y gweinydd neu gyfathrebwr e-bost a rhannu'r wybodaeth ganlynol:
+    
+    Mae eich tystysgrif yn cynnwys yr un rhifau cyfresol a thystysgrif arall wedi ei gyhoeddi gan yr awdurdod tystysgrifau.  Defnyddiwch dystysgrif newydd yn cynnwys rhif cyfresol unigryw.
+
+ssl-error-export-only-server = Methu cyfathrebu'n ddiogel. Nid yw'r cyfoed cyn cynnal amgryptiad lefel uchel.
+ssl-error-us-only-server = Methu cyfathrebu'n ddiogel. Mae'r cyfoed angen amgryptiad lefel uchel nad yw'n cael ei gynnal.
+ssl-error-no-cypher-overlap = Methu cyfathrebu'n ddiogel gyda cyfoed: dim algorithm(au) amgrypriad cyffredin.
+ssl-error-no-certificate = Methu canfod tystysgrif neu allwedd angenrheidiol ar gyfer dilysu.
+ssl-error-bad-certificate = Methu cyfathrebu'n ddiogel gyda'r cyfoed: tystysgrif y cyfoed wedi ei wrthod.
+ssl-error-bad-client = Mae'r gweinydd wedi derbyn data gwael gan y cleient.
+ssl-error-bad-server = Mae'r cleient wedi derbyn data gwael gan y gweinydd.
+ssl-error-unsupported-certificate-type = Maeth o dystysgrif sydd heb ei gynnal.
+ssl-error-unsupported-version = Mae'r cyfoed yn defnyddio math o brotocol diogel nad yw'n cael ei gynnal.
+ssl-error-wrong-certificate = Methodd dilysu'r cleient: nid yw allwedd breifat yng nghronfa ddata allweddi yn cydfynd â'r allwedd gyhoeddus yng gntonfa ddata'r tystysgrifau.
+ssl-error-bad-cert-domain = Methu cyfathrebu'n ddiogel gyda'r cyfoed; nid yw'r enw parth yn cydfynd â thystysgrif y gweinydd.
+ssl-error-post-warning = Cod gwall SSL heb ei adnabod.
+ssl-error-ssl2-disabled = Dim ond SSL fersiwn 2 mae'r cyfoed yn ei gynnal ac mae wedi ei analluogi'n lleol.
+ssl-error-bad-mac-read = Derbyniodd SSL gofnod gyda Chod Dilysu Neges anghywir.
+ssl-error-bad-mac-alert = Mae cyfoed SSL yn cofnodi Cod Dilysu Neges anghywir.
+ssl-error-bad-cert-alert = Nid yw cyfode SSL: yn gallu dilysu eich tystysgrif.
+ssl-error-revoked-cert-alert = Mae'r cyfoed SSL wedi gwrthod eich tystysgrif fel un wedi ei atal.
+ssl-error-expired-cert-alert = Mae'r cyfoed SSL wedi gwrthod eich tystysgrif fel un wedi dod i ben.
+ssl-error-ssl-disabled = Methu cysylltu: SSL wedi ei analluogi.
+ssl-error-fortezza-pqg = Methu cysylltu: cyfoed SSL mewn parth FORTEZZA arall.
+ssl-error-unknown-cipher-suite = Mae cais wedi ei dderbyn am swit seiffr SSL.
+ssl-error-no-ciphers-supported = Nid oes swit seiffr ar gael ac wedi eu galluogi yn y rhaglen hon.
+ssl-error-bad-block-padding = Mae SSL wedi derbyn cofnod gyda phadin bloc gwael.
+ssl-error-rx-record-too-long = Mae SSL wedi derbyn cofnod sy'n hirach na'r hyd posib.
+ssl-error-tx-record-too-long = Mae SSL wedi ceisio anfon cofnod sy'n fwy na'r hyd posib.
+ssl-error-rx-malformed-hello-request = Mae SSL wedi derbyn neges ysgwyd llaw Cais Helo anffurf.
+ssl-error-rx-malformed-client-hello = Mae SSL wedi derbyn neges ysgwyd llaw Helo Cleient anffurf.
+ssl-error-rx-malformed-server-hello = Mae SSL wedi derbyn neges ysgwyd llaw Helo Gweinydd anffurf.
+ssl-error-rx-malformed-certificate = Mae SSL wedi derbyn neges ysgwyd llaw Tystysgrif anffurf.
+ssl-error-rx-malformed-server-key-exch = Mae SSL wedi derbyn neges ysgwyd llaw Cyfnewid Allwedd Gweinydd anffurf.
+ssl-error-rx-malformed-cert-request = Derbyniodd SSL neges ysgwyd llaw Cais Tystysgrif anffurfedig.
+ssl-error-rx-malformed-hello-done = Derbyniodd SSL neges ysgwyd llaw Server Hello Done anffurfedig.
+ssl-error-rx-malformed-cert-verify = Mae SSL wedi derbyn neges ysgwyd llaw Dilysu Tystysgrif anffurf.
+ssl-error-rx-malformed-client-key-exch = Mae SSL wedi derbyn neges ysgwyd llaw Cyfnewid Allwedd Cleient anffurf.
+ssl-error-rx-malformed-finished = Mae SSL wedi derbyn neges ysgwyd llaw Terfynnwyd annfurf.
+ssl-error-rx-malformed-change-cipher = Mae SSL wedi derbyn cofnod Manyleb Seiffr Newid anffurf.
+ssl-error-rx-malformed-alert = Mae SSL wedi derbyn cofnod Rhybudd anffurf.
+ssl-error-rx-malformed-handshake = Mae SSL wedi derbyn cofnod Ysgwyd Llaw anffurf.
+ssl-error-rx-malformed-application-data = Mae SSL wedi derbyn cofnod Data Rhaglen Anffurf.
+ssl-error-rx-unexpected-hello-request = Mae SSL wedi derbyn neges ysgwyd llaw Cais Helo annisgwyl.
+ssl-error-rx-unexpected-client-hello = Mae SSL wedi derbyn neges ysgwyd llaw Helo Cleient annisgwyl.
+ssl-error-rx-unexpected-server-hello = Mae SSL wedi derbyn neges ysgwyd llaw Helo Gweinydd annisgwyl.
+ssl-error-rx-unexpected-certificate = Mae SSL wedi derbyn neges ysgwyd llaw Tystysgrif annisgwyl.
+ssl-error-rx-unexpected-server-key-exch = Mae SSL wedi derbyn neges ysgwyd llaw Cyfnewid Allwedd Gweinydd annisgwyl.
+ssl-error-rx-unexpected-cert-request = Mae SSL wedi derbyn neges ysgwyd llaw Cais Tystysgrif annisgwyl.
+ssl-error-rx-unexpected-hello-done = Mae SSL wedi derbyn neges ysgwyd llaw Helo Gweinydd Cwblhawyd annisgwyl.
+ssl-error-rx-unexpected-cert-verify = Mae SSL wedi derbyn neges ysgwyd llaw Dilysu Tystysgrif annisgwyl.
+ssl-error-rx-unexpected-client-key-exch = Mae SSL wedi derbyn neges ysgwyd llaw Cyfnewid Allwedd Cleient annisgwyl.
+ssl-error-rx-unexpected-finished = Mae SSL wedi derbyn neges ysgwyd llaw Terfynnu annisgwyl.
+ssl-error-rx-unexpected-change-cipher = Mae SSL wedi derbyn cofnod Manyleb Seiffr Newid annisgwyl.
+ssl-error-rx-unexpected-alert = Mae SSL wedi derbyn cofnod Rhybudd annisgwyl.
+ssl-error-rx-unexpected-handshake = Mae SSL wedi derbyn cofnod Ysgwyd Llaw annisgwyl.
+ssl-error-rx-unexpected-application-data = Mae SSL wedi derbyn cofnod Data Rhaglen annisgwyl.
+ssl-error-rx-unknown-record-type = Mae SSL wedi derbyn cofnod gyda math data anhysbys.
+ssl-error-rx-unknown-handshake = Mae SSL wedi derbyn negws ysgwyd llaw gyda math data anhysbys.
+ssl-error-rx-unknown-alert = Mae SSL wedi derbyn cofnod rhybudd gyda math disgrifiad anhysbys.
+ssl-error-close-notify-alert = Mae cyfoed SSL wedi cau'r cysylltiad.
+ssl-error-handshake-unexpected-alert = Nid oess y cyfoed SSL yn disgwyl y negws ysgwyd llaw dderbyniodd.
+ssl-error-decompression-failure-alert = Nid oess y cyfoed SSL yn gallu datgywasgu'r cofnod SSL y derbyniodd yn llwyddiannus.
+ssl-error-handshake-failure-alert = Nid oedd cyfoed SSL yn gallu negydu set dderbyniol o baramedrau diogelwch.
+ssl-error-illegal-parameter-alert = Gwrthododd cyfoed SSL neges ysgwyd llaw oherwydd cynnwys annerbyniol.
+ssl-error-unsupported-cert-alert = Nid yw cyfoed SSL yn cynnal tystysgrifau o'r matha mae wedi eu derbyn.
+ssl-error-certificate-unknown-alert = Mae gan gyfoed SSL anhawster amhenodol gyda'r dystysgrif mae wedi ei derbyn.
+ssl-error-generate-random-failure = Profodd SSL fethiant a'o gynhyrchydd rhifau hap.
+ssl-error-sign-hashes-failure = Methu llofnodi data digidol angenrheidiol ar gyfer dilysu eich tystysgrif.
+ssl-error-extract-public-key-failure = Roedd SSL yn methu tynnu'r allwedd gyhoeddus o dystysgrif y cyfoed.
+ssl-error-server-key-exchange-failure = Bu methiant amhenodol wrth brosesu ysgwyd llaw Cyfnewid Allwedd Gweinydd SSL.
+ssl-error-client-key-exchange-failure = Bu methiant amhenodol wrth brosesu ysgwyd llaw Cyfnewid Allwedd Gweinydd SSL.
+ssl-error-encryption-failure = Methodd algorithm amgryptio swmp data yn y swit seiffr hwn.
+ssl-error-decryption-failure = Methodd algorithm dadgryptio swmp data yn y swit seiffr hwn.
+ssl-error-socket-write-failure = Merhodd ymgais i ysgrifennu data amgryptiedig i'r soced gwaelodol.
+ssl-error-md5-digest-failure = Methodd swyddogaeth crynhoi MD5.
+ssl-error-sha-digest-failure = Methodd swyddogaeth crynhoi SHA-1.
+ssl-error-mac-computation-failure = Methodd cyfrifiant MAC.
+ssl-error-sym-key-context-failure = Methu creu cyd-destun Allwedd Symetrig.
+ssl-error-sym-key-unwrap-failure = Methu dadlapio'r allwedd Symetrig yn neges Cyfnewid Allwedd Cleient.
+ssl-error-pub-key-size-limit-exceeded = Ceisiodd Gweinydd SSL â defnyddio allwedd gyhoeddus domestig gyda swit seiffr allforio.
+ssl-error-iv-param-failure = Methodd cod PKCS11 â throsi IV i baram.
+ssl-error-init-cipher-suite-failure = Methu cychwyn y swit seiffr hwn.
+ssl-error-session-key-gen-failure = Methodd y cleient â chynhyrchu allweddi sesiwn ar gyfer sesiwn SSL.
+ssl-error-no-server-key-for-alg = Nid oes gan y gweinydd allwedd ar gyfer ymgais algoryddm cyfnewid allweddi.
+ssl-error-token-insertion-removal = Mewnosodwyd neu dynnwyd tocyn PKCS#11 wrth i'r weithred fod mewn grym.
+ssl-error-token-slot-not-found = Ni fu modd canfod tocyn PKCS#11 i gyflawni'r weithredu.
+ssl-error-no-compression-overlap = Methu cyfathrebu'n ddiogel gyda'r cyfoed: dim algorithmau(au) cywasgu cyffredin.
+ssl-error-handshake-not-completed = Methu cychwyn ysgwyd llaw SSL arall nes i'r ysgwyd llaw cyfredol ddod i ben.
+ssl-error-bad-handshake-hash-value = Wedi derbyn gwerthoedd hash ysgwyd llaw anghywir gan y cyfoed.
+ssl-error-cert-kea-mismatch = Nid oes modd defnyddio'r dystysgrif hon gyda'r algorythm cyfnewid allwedd hwn.
+ssl-error-no-trusted-ssl-client-ca = Nid oes ymddiriedaeth i awdurdod tystysgrifo ar gyfer dilysu cleient SSL.
+ssl-error-session-not-found = Nid yw enw sesiwn SSL y cleient wedi ei ganfod yn storfa dros dro sesiwn y gweinydd.
+ssl-error-decryption-failed-alert = Methodd y cyfoed â dadgryptio cofnod SSL mae wedi ei derbyn.
+ssl-error-record-overflow-alert = Derbyniodd y cyfoed gofnod SSL sy'n hirach na'r hyn ganiateir.
+ssl-error-unknown-ca-alert = Nid yw'r cyfoed yn adnabod nac ymddiried yn y AT sydd wedi cyhoeddi eich tystysgrif.
+ssl-error-access-denied-alert = Derbyniodd y cyfoed dystysgrif dilys , ond gwrthodwyd mynediad.
+ssl-error-decode-error-alert = Nid oedd y cyfoed yn gallu dadgodio neges ysgwyd llaw SSL.
+ssl-error-decrypt-error-alert = Mae'r cyfoed yn cofnodi methiant llofnod dilysu neu gyfnewid allweddi.
+ssl-error-export-restriction-alert = Mae'r cyfoed yn cofnodi negodi nad yw'n gytûn â'r rheoliadau allforio.
+ssl-error-protocol-version-alert = Mae'r cofnod yn cofnodi ferwiwn protocol anghymarus neu heb ei gynnal.
+ssl-error-insufficient-security-alert = Mae'r gweinydd angen seiffr mwy diogel na'r rhai sy'n cael eu cynnal gan y cleient.
+ssl-error-internal-error-alert = Mae'r cyfoed yn nodi gwall mewnol.
+ssl-error-user-canceled-alert = Mae'r cyfoed wedi diddymu ysgwyd llaw.
+ssl-error-no-renegotiation-alert = Nid yw'r cyfoed yn caniatáu ailnegodi paramedrau diogelwch SSL.
+ssl-error-server-cache-not-configured = Nid yw storfa dros dro gweinydd SSL wedi ei ffurfweddu na'i analluogi ar gyfer y soced hwn.
+ssl-error-unsupported-extension-alert = Nid yw'r cyfoed SSL yn cynnal yr estyniad helo TLS gofynnwys amdano.
+ssl-error-certificate-unobtainable-alert = Nid yw'r cyfoed SSL y gallu cael eich tystysgrif o'r URL darparwyd.
+ssl-error-unrecognized-name-alert = Nid oes gan y cyfoed SSL dystysgrif ar gyfer yr enw DNS gofynnwyd amdani.
+ssl-error-bad-cert-status-response-alert = Nid oedd y cyfoed SSL yn gallu cael ymateb OCSP ar gyfer ei dystysgrif.
+ssl-error-bad-cert-hash-value-alert = Adroddodd cyfoed yr SSL gwerth hash tystysgrif gwael.
+ssl-error-rx-unexpected-new-session-ticket = Mae SSL wedi derbyn neges ysgwyd llaw Tocyn Sesiwn Newydd annisgwyl.
+ssl-error-rx-malformed-new-session-ticket = Mae SSL wedi derbyn neges ysgwyd llaw Tocyn Sesiwn Newydd.
+ssl-error-decompression-failure = Mae SSL wedi derbyn cofnod cywasgedig nad oedd modd ei datgywasgu.
+ssl-error-renegotiation-not-allowed = Nid oes modd ail negodi ar y soced SSL hwn.
+ssl-error-unsafe-negotiation = Ceisiodd y cyfoed ysgwyd llaw hen ffurf (bregus posib).
+ssl-error-rx-unexpected-uncompressed-record = Derbyniodd SSL gofnod datgywasgedig annisgwyl.
+ssl-error-weak-server-ephemeral-dh-key = Derbyniodd SSL allwedd gwan Diffie-Hellman darfodedig yn neges ysgwyd llaw Cyfnewidiad Allwedd Gweinydd.
+ssl-error-next-protocol-data-invalid = Derbyniodd SSL ddata estyniad NPN annilys.
+ssl-error-feature-not-supported-for-ssl2 = Nid yw'r nodwedd SSL hwn yn cael ei gynnal ar gyfer cysylltiadau SSL 2.0.
+ssl-error-feature-not-supported-for-servers = Nid yw'r nodweddion SSL hyn yn cael eu cynnal ar weinyddion.
+ssl-error-feature-not-supported-for-clients = Nid yw'r nodweddion SSL hyn yn cael eu cynnal ar raglenni.
+ssl-error-invalid-version-range = Nid ys ystod fersiwn SSL yn ddilys.
+ssl-error-cipher-disallowed-for-version = Dewisodd cyfoed swît seiffr SSL sydd wedi ei atal ar gyfer y protocol fersiwn yma.
+ssl-error-rx-malformed-hello-verify-request = Mae SSL wedi derbyn neges ysgwyd llaw Hello Verify Request anffurf.
+ssl-error-rx-unexpected-hello-verify-request = Mae SSL wedi derbyn neges ysgwyd llaw Hello Verify Request annisgwyl.
+ssl-error-feature-not-supported-for-version = Nid yw'r nodwedd SSL hwn yn cael ei gynnal ar gyfer y fersiwn protocol.
+ssl-error-rx-unexpected-cert-status = Mae SSL wedi derbyn neges ysgwyd llaw Statws Tystysgrif annisgwyl.
+ssl-error-unsupported-hash-algorithm = Algorithm hash anghynaledig wedi ei ddefnyddio gan gyfoed TLS.
+ssl-error-digest-failure = Methodd swyddogaeth crynhoi.
+ssl-error-incorrect-signature-algorithm = Algorithm llofnod anghywir wedi ei bennu mewn elfen llofnod digidol.
+ssl-error-next-protocol-no-callback = Roedd yr estyniad negydu protocol yn barod ond cafodd yr adalw ei glirio cyn fod ei angen.
+ssl-error-next-protocol-no-protocol = Nid yw'r gweinydd yn cynnal protocolau mae'r client yn ei hysbysu yn yr estyniad ALPN.
+ssl-error-inappropriate-fallback-alert = Gwrthododd y gweinydd yr ysgwyd llaw oherwydd i'r client israddio i fersiwn TLS is na mae'r gweinydd yn ei gynnal.
+ssl-error-weak-server-cert-key = Mae tystysgrif y gweinydd yn cynnwys allwedd gyhoeddus sy'n rhy wan.
+ssl-error-rx-short-dtls-read = Dim digon o le ar y byffer ar gyfer cofnod DTLS.
+ssl-error-no-supported-signature-algorithm = Heb ffurfweddu algorithm llofnod TLS sy'n cael ei gynnal.
+ssl-error-unsupported-signature-algorithm = Mae'r cyfoed yn defnyddio cyfuniad o lofnod a'r algorithm hash sydd ddim yn cael ei gynnal.
+ssl-error-missing-extended-master-secret = Mae'r cyfoed wedi ceisio ailgychwyn heb yr estyniad extended_master_secret cywir.
+ssl-error-unexpected-extended-master-secret = Mae'r cyfoed wedi ceisio ailgychwyn gyda estyniad extended_master_secret annisgwyl.
+sec-error-io = Digwyddodd gwall I/O yn ystod dilysu diogelwch.
+sec-error-library-failure = methiant llyfrgell diogelwch.
+sec-error-bad-data = llyfrgell diogelwch: derbyniwyd data gwael.
+sec-error-output-len = llyfrgell diogelwch: gwall hyd allbwn.
+sec-error-input-len = mae'r llyfrgell diogelwch wedi profi gwall hyd mewnbwn.
+sec-error-invalid-args = llyfrgell diogewlch: ymrysonderau annilys.
+sec-error-invalid-algorithm = llyfrgell diogewlch: algorithm annilys.
+sec-error-invalid-ava = llyfrgell diogelwch: AVA annilys.
+sec-error-invalid-time = Llinyn amser fformatiwyd yn annilys.
+sec-error-bad-der = llyfrgell diogelwch: neges amgodiad-DER wedi ei fformatio'n annilys.
+sec-error-bad-signature = Mae gan y tystysgrif cyfoed lofnod annilys.
+sec-error-expired-certificate = Tystysgrif Cyfoed wedi dod i ben.
+sec-error-revoked-certificate = Tystysgrif Cyfoed wedi ei atal.
+sec-error-unknown-issuer = Cyhoeddwr Tystysgrif Cyfoed heb ei adnabod.
+sec-error-bad-key = Allwedd cyhoeddus y cyfoed yn annilys.
+sec-error-bad-password = Mae'r cyfrinair diogelwch yn anghywir.
+sec-error-retry-password = Cyfrinair newydd yn anghywir. Ceisiwch eto.
+sec-error-no-nodelock = llyfrgell diogelwch: dim clo nod.
+sec-error-bad-database = llyfrgell diogewlch: cronfa ddata gwael.
+sec-error-no-memory = llyfrgell diogewlch: methiant dynodicof.
+sec-error-untrusted-issuer = Cyhoeddwr tystysgrif cyfoed wedi ei nodi fel annibynadwy gan y defnyddiwr.
+sec-error-untrusted-cert = Tstysgrif cyfoed wedi ei nodi fel annibynadwy gan y defnyddiwr.
+sec-error-duplicate-cert = Mae'r tystysgrif yn bodoli yn eich cronfa ddata.
+sec-error-duplicate-cert-name = Mae enw'r dystysgrif llwythwyd i lawr yn dyblygu un sydd yn eich cronfa ddata.
+sec-error-adding-cert = Gwall ychwanegu tystysgrif i'r gronfa ddata.
+sec-error-filing-key = Gwall ail-lanw allwedd ar gyfer y dystysgrif.
+sec-error-no-key = Nid oes modd dod o hyd i allwedd breifat y dystysgrif yng gronfa ddata allweddi
+sec-error-cert-valid = Mae'r dystysgrif yn ddilys.
+sec-error-cert-not-valid = Nid yw'r dystysgrif yn ddilys.
+sec-error-cert-no-response = Llyfrgell Tyst: Dim Ymateb
+sec-error-expired-issuer-certificate = Ma tystysgrif cyhoeddwr y dystysgrif wedi dod i ben. Gwiriwch ddyddiad ac amser eich system.
+sec-error-crl-expired = Mae CRL cyhoeddwr y dystysgrif wedi dod i ben. Diweddarwch neu gwiriwch ddyddiad ac amser eich system.
+sec-error-crl-bad-signature = Mae i CRL cyhoeddwr y dystysgrif lofnod annilys.
+sec-error-crl-invalid = Mae i'r CRL newydd fformat annilys.
+sec-error-extension-value-invalid = Mae gwerth estyniad tystysgrif yn annilys.
+sec-error-extension-not-found = Heb ganfod estyniad tystysgrif.
+sec-error-ca-cert-invalid = Tystysgrif y cyhoeddwr yn annilys.
+sec-error-path-len-constraint-invalid = Mae cyfyniad hyd llwybr y dystysgrif yn annilys.
+sec-error-cert-usages-invalid = Mae maes defnydd tystysgrif yn annilys.
+sec-internal-only = **Modiwl Mewnol YN UNIG**
+sec-error-invalid-key = Nid yw'r allwedd yn cynnal y weithred hon.
+sec-error-unknown-critical-extension = Mae'r dystysgrif yn cynnwys estyniad critigol anhysbys.
+sec-error-old-crl = Nid yw'r CRL yn hwyrach na'r un gyfredol.
+sec-error-no-email-cert = Heb ei hamgryptio na'i harwyddo: nid oes gennych dystysgrif e-bost eto.
+sec-error-no-recipient-certs-query = Heb ei hamgryptio: nid oes gennych dystysgrif ar gyfer pob un derbynnydd.
+sec-error-not-a-recipient = Methu dadgryptio: nid ydych yn dderbynnydd, neu heb ganfod tystysgrif cytûn neu allwedd breifat.
+sec-error-pkcs7-keyalg-mismatch = Methu dadgryptio: nid yw amgryptiad yr algorithm yn gytûn â'ch tystysgrif.
+sec-error-pkcs7-bad-signature = Methodd dilysu llofnod: heb ganfod llofnodwr, wedi canfod gormod o lofnodwyr neu data amhriodol neu llwgr.
+sec-error-unsupported-keyalg = Allwedd algorithm heb ei gynnal neu anhysbys.
+sec-error-decryption-disallowed = Methu dadgryptio: wedi ei amgryptio gan ddefnyddio algorithm gwaharddedig neu faint allwedd.
+xp-sec-fortezza-bad-card = Nid yw cerdyn Fortezza wedi ei gychwyn yn gywir. Tynnwch y cerdyn a'i ddychwelyd ar y cyhoeddwr.
+xp-sec-fortezza-no-card = Heb ganfod cerdyn Fortezza
+xp-sec-fortezza-none-selected = Heb ddewis cerdyn Fortezza
+xp-sec-fortezza-more-info = Dewiswch bersonoliaeth i dderbyn mwy o wybodaeth amdano
+xp-sec-fortezza-person-not-found = Heb ddarganfod personoliaeth
+xp-sec-fortezza-no-more-info = Dim rhagor o wybodaeth ar Personoliaeth hwnnw
+xp-sec-fortezza-bad-pin = Pin annilys
+xp-sec-fortezza-person-error = Methu cychwyn personoliaethau Fortezza.
+sec-error-no-krl = Heb ganfod KRL ar gyfer tystysgrif y wefan.
+sec-error-krl-expired = Mae KRL y wefan wedi dod i ben.
+sec-error-krl-bad-signature = Mae llofnod annilys i KRL tystysgrif y wefan.
+sec-error-revoked-key = Mae allwedd tystysgrif y wefan honn wedi ei therfynnu.
+sec-error-krl-invalid = Mae fformat annilys i'r KRL newydd.
+sec-error-need-random = llyfrgell diogelwch: angen data hap.
+sec-error-no-module = llyfrgell diogelwch: nid oes modiwl diogelwch all gyflawni'r weithred angenrheidiol.
+sec-error-no-token = Nid yw'r cerdyn neu docyn diogelwch yn bodoli, angen ei gychwyn neu wedi ei dynnu.
+sec-error-read-only = llyfrgell diogelwch: cronfa ddata darllen yn unig.
+sec-error-no-slot-selected = Heb ddewis slot neu docyn.
+sec-error-cert-nickname-collision = Mae tystysgrif gyda'r un llysenw yn bodoli eisoes.
+sec-error-key-nickname-collision = Mae allwedd gyda'r un llysenw yn bodoli eisoes.
+sec-error-safe-not-created = gwall wrth greu gwrthrych diogel
+sec-error-baggage-not-created = gwall werth greu gwrthrych pecyn
+xp-java-remove-principal-error = Methu tynnu'r prif
+xp-java-delete-privilege-error = Methu dileu'r fraint
+xp-java-cert-not-exists-error = Nid oes gan y prif dystysgrif
+sec-error-bad-export-algorithm = Nid oes caniatâd i'r algorithm angenrheidiol.
+sec-error-exporting-certificates = Gwall wrth geisio allforio tystysgrifau.
+sec-error-importing-certificates = Gwall wrth geisio mewnforio tystysgrifau.
+sec-error-pkcs12-decoding-pfx = Methu mewnforio. Gwall dadgodio. Nid yw'r ffeil yn ddilys.
+sec-error-pkcs12-invalid-mac = Methu mewnforio. MAC annilys. Cyfrinair anghywir neu ffeil llwgr.
+sec-error-pkcs12-unsupported-mac-algorithm = Methu mewnforio. Nid yw'r algorithm MAC yn cael ei gynnal.
+sec-error-pkcs12-unsupported-transport-mode = Methu mewnforio. Dim ond cywirdeb cyfrinair a moddau preifatrwydd sy'n cael eu cynnal.
+sec-error-pkcs12-corrupt-pfx-structure = Methu mewnforio. Mae strwythur y ffeil yn llwgr.
+sec-error-pkcs12-unsupported-pbe-algorithm = Methu mewnforio. Nid yw algorithm yr amgryptio'n cael ei gynnal.
+sec-error-pkcs12-unsupported-version = Methu mewnforio. Nid yw fersiwn y ffeil yn cael ei chynnal.
+sec-error-pkcs12-privacy-password-incorrect = Methu mewnforio. Cyfrinair preifatrwydd anghywir.
+sec-error-pkcs12-cert-collision = Methu mewnforio. Mae'r un llysenw yn bodoli eisoes yn y gronfa ddata.
+sec-error-user-cancelled = Pwysodd y defnyddiwr diddymu.
+sec-error-pkcs12-duplicate-data = Heb ei fewnforio, eisoes yn y gronfa ddata.
+sec-error-message-send-aborted = Heb anfon y neges.
+sec-error-inadequate-key-usage = Defnydd allwedd y dystysgrif yn annigonol ar gyfer y weithred ymgeisiwyd.
+sec-error-inadequate-cert-type = Nid yw'r math o dystysgrif wedi ei gymeradwyo ar gyfer y rhaglen.
+sec-error-cert-addr-mismatch = Nid yw'r cyfeiriad yn y dysstysgrif llofnodi yn cydfynd â'r cyferiad ym mhenyn y neges.
+sec-error-pkcs12-unable-to-import-key = Methu mewnforio. Gwall wrth geisio mewnforio'r allwedd breifat.
+sec-error-pkcs12-importing-cert-chain = Methu mewnforio. Gwall wrth geisio mewnforio cadwyn tystysgrif.
+sec-error-pkcs12-unable-to-locate-object-by-name = Methu allforio. Methu lleoli tystysgrif neu allwedd yn ôl tystysgrif.
+sec-error-pkcs12-unable-to-export-key = Methu allforio. Nid oedd modd canfod yr Allwedd Breifat a'i hallforio.
+sec-error-pkcs12-unable-to-write = Methu allforio. Methu ysgrifennu i'r ffeil allforio.
+sec-error-pkcs12-unable-to-read = Methu mewnforio. Methu darllen y ffeil mewnforio.
+sec-error-pkcs12-key-database-not-initialized = Methu allforio. Cronfa ddata'r allwedd yn llwgr neu wedi ei dileu.
+sec-error-keygen-fail = Methu cynhyrchu par o allweddi cyhoeddus/preifat.
+sec-error-invalid-password = Mae'r cyfrinair rhoddwyd yn annilys. Dewiswch un arall.
+sec-error-retry-old-password = Mae'r hen gyfrinair wedi ei gosod yn anghywir. Ceisiwch eto.
+sec-error-bad-nickname = Mae llysenw'r dystysgrif yn cael ei defnyddio eisoes.
+sec-error-not-fortezza-issuer = Mae gan y cadwyn FORTEZZA cyfoed dystysgrif an FORTEZZA.
+sec-error-cannot-move-sensitive-key = Nid oes modd symud allwedd sensitif i'r slot lle mae ei hangen.
+sec-error-js-invalid-module-name = Enw modiwl annilys.
+sec-error-js-invalid-dll = Llwybr/enw ffeil modiwl annilys
+sec-error-js-add-mod-failure = Methu ychwanegu modiwl
+sec-error-js-del-mod-failure = Methu dileu modiwl
+sec-error-old-krl = Nid yw'r KRL newydd yn hwyrach na'r un cyfredol.
+sec-error-ckl-conflict = Mae gan y CKL gyhoeddwr gwahanol i'r CKL cyfredol. Dilëwch y CKL cyfredol.
+sec-error-cert-not-in-name-space = Nid oes gan Awdurdod Tystysgrifo'r dystysgrif hon hawl i gyhoeddi tystysgrif yn yr enw hwn.
+sec-error-krl-not-yet-valid = Nid yw rhestr dileu'r allwedd ar gyfer y dystysgrif yn ddilys eto.
+sec-error-crl-not-yet-valid = Nid yw rhestr dileu'r dystysgrif ar gyfer y dystysgrif yn ddilys eto.
+sec-error-unknown-cert = Nid oedd modd canfod y dystysgrif ofynnol.
+sec-error-unknown-signer = Nid oedd modd canfod tystysgrif y llofnodwr.
+sec-error-cert-bad-access-location = Mae gan leoliad gweinydd statws y dystysgrif fformat annilys.
+sec-error-ocsp-unknown-response-type = Nid oes modd dadgodio ymateb OCSP yn llawn; mae o fath anhysbys.
+sec-error-ocsp-bad-http-response = Dychwelodd gweinydd OCSP ddata HTTP annisgwyl/annilys.
+sec-error-ocsp-malformed-request = Mae'r gweinydd OCSP wedi pennu'r cais fel un llwgr neu heb ei ffurfio'n gywir.
+sec-error-ocsp-server-error = Profodd y gweinydd OCSP wall mewnol.
+sec-error-ocsp-try-server-later = Mae gweinydd yr OCSP yn awgrymu y dylech geisio eto.
+sec-error-ocsp-request-needs-sig = Mae angen llofnod ar gyfer y gweinydd OCSP.
+sec-error-ocsp-unauthorized-request = Mae'r gweinydd OCSP wedi gwrthod y cais fel un anawdurdodedig.
+sec-error-ocsp-unknown-response-status = Dychwelodd y gweinydd OCSP statws heb ei gydnabod.
+sec-error-ocsp-unknown-cert = Nid oes gan y gweinydd OCSP statws ar gyfer y dystysgrif.
+sec-error-ocsp-not-enabled = Rhaid galluogi OCSP cyn cyflawni'r weithred.
+sec-error-ocsp-no-default-responder = Rhaid gosod ymatebwr rhagosodedig yr OCSP cyn cyflawni'r weithred.
+sec-error-ocsp-malformed-response = Roedd ymateb y gweinydd OCSP yn llwgr neu heb ei ffurfio'n gywir.
+sec-error-ocsp-unauthorized-response = Nid oes gan lofnodwr ymateb yr OCSP yr awdurdod i ddarparu statws y dystysgrif.
+sec-error-ocsp-future-response = Nid yw ymateb yr OCSP nyn ddilys eto (mae'n cynnwys dyddiad yn y dyfodol).
+sec-error-ocsp-old-response = Mae ymateb yr OCSP yn cynnwys hen ddata.
+sec-error-digest-not-found = Heb ganfod Crynodeb CMS neu PKCS #7 yn y neges gyda'r llofnod.
+sec-error-unsupported-message-type = Nid yw'r math o neges CMS neu PKCS #7 yn cael eu cynnal.
+sec-error-module-stuck = Nid oeddd modd tynnu modiwl PKCS #11 am ei fod yn cael ei ddefnyddio.
+sec-error-bad-template = Methu dadgodio data ASN.1. Roedd y templed yn annilys.
+sec-error-crl-not-found = Methu canfod CRL cytûn.
+sec-error-reused-issuer-and-serial = Rydych yn ceisio mewnforio tystysgrif gyda'r un cyhoeddwr/cyfres a'r dystysgrif gyfredol, ond nid yr un dystysgrif ydyw.
+sec-error-busy = Meddodd yr NSS â chau. Gwrthychau yn dal mewn defnydd.
+sec-error-extra-input = Mae'r neges DER amgodedig yn cynnwys data ychwanegol heb ei ddefnyddio.
+sec-error-unsupported-elliptic-curve = Cromlin eliptig heb ei gynnal.
+sec-error-unsupported-ec-point-form = Ffurf pwynt cromlin eliptig heb ei gynnal.
+sec-error-unrecognized-oid = Adnabyddwr Gwrthrychau Anhysbys.
+sec-error-ocsp-invalid-signing-cert = Tysytysgrif llofnodi OCSP anniltys yn ymateb yr OCSP.
+sec-error-revoked-certificate-crl = Mae'r dystysgrif wedi ei diddymu yn rhestr diddymu cyhoeddwr y dystysgrif.
+sec-error-revoked-certificate-ocsp = Mae tystysgrif adrodd ymatebion OCSP y cyhoeddwr wedi ei diddymu.
+sec-error-crl-invalid-version = Mae gan Rhestr Diddymu Tystysgrifau'r Cyhoeddwr rhif fersiwn anhysbys.
+sec-error-crl-v1-critical-extension = Mae gan Rhestr Diddymu Tystysgrif V1 y cyhoeddwr estyniad critigol.
+sec-error-crl-unknown-critical-extension = Mae gan Rhestr Diddymu Tystysgrif V2 y cyhoeddwr estyniad critigol anhysbys.
+sec-error-unknown-object-type = Gwrthrych o fath anhysbys wedi ei bennu.
+sec-error-incompatible-pkcs11 = Mae gyrrwr PKCS #11 yn tarfu'r manyleb mewn dull anghymarus.
+sec-error-no-event = Mae digwyddiad slot newydd ar gael ar hyn o bryd.
+sec-error-crl-already-exists = Mae'r CRL yn bodoli eisoes.
+sec-error-not-initialized = Nid yw'r NSS wedi ei gychwyn.
+sec-error-token-not-logged-in = Methodd y weithred gan nad yw tocyn PKCS#11 wedi ei fewngofnodi.
+sec-error-ocsp-responder-cert-invalid = Mae ffurfweddiad tystysgrif ymatebwr OCSP yn anilys.
+sec-error-ocsp-bad-signature = Mae gan ymateb yr OCSP lofnod annilys.
+sec-error-out-of-search-limits = Mae chwilio dilysu'r dystysgrif tu llan i derfynnau ei chwilio
+sec-error-invalid-policy-mapping = Mae mapio polisi yn cynnwys anypolicy
+sec-error-policy-validation-failed = Mae cadwyn y dystysgrif yn methu'r dilysiad polisi
+sec-error-unknown-aia-location-type = Math lleoliad anhysbys yn estyniad tystysgrif AIA
+sec-error-bad-http-response = Dychwelodd y gweinydd ymateb HTTP gwael
+sec-error-bad-ldap-response = Dychwelodd y gweinydd ymateb LDAP gwael
+sec-error-failed-to-encode-data = Methwyd amgosio data gydag amgodiwr ASN1
+sec-error-bad-info-access-location = Lleoliad mynediad gwybodaeth gwael mewn estyniad tystysgrif
+sec-error-libpkix-internal = Digwyddodd gwall mewnol libpkix yn ystod dilysiad tystysgrif.
+sec-error-pkcs11-general-error = Dychwelodd modiwl PKCS #11 CKR_GENERAL_ERROR, gan awgrymu fod gwall anadferadwy wedi digwydd.
+sec-error-pkcs11-function-failed = Dychwelodd PKCS #11 CKR_FUNCTION_FAILED, gan awgrymu nad oedd modd cyflawni'r swyddogaeth ofynnol. Efallai bydd cyflawni'r un weithred eto'n llwyddo.
+sec-error-pkcs11-device-error = Dychwelodd modiwl PKCS #11 CKR_DEVICE_ERROR, gan awgrymu fod yna broblem gyda'r tocyn neu'r slot.
+sec-error-bad-info-access-method = Dull mynediad gwybodaeth anhysbys mewn estyniad tystysgrif.
+sec-error-crl-import-failed = Gwall wrth geisio mewnforio CRL.
+sec-error-expired-password = Mae'r cyfrinair wedi dod i ben.
+sec-error-locked-password = Mae'r cyfrinair wedi ei gloi.
+sec-error-unknown-pkcs11-error = Gwall PKCS #11 anhysbys.
+sec-error-bad-crl-dp-url = URL annilys neu heb ei gynnal yn enw pwynt dosbarthiad CRL.
+sec-error-cert-signature-algorithm-disabled = Cafodd y dystysgrif ei llofnodi gan ddefnyddio algorithm llofnod sydd wedi ei analluogi am nad yw'n ddiogel.
+mozilla-pkix-error-key-pinning-failure = Mae'r gweinydd yn defnyddio pinio allwedd (HPKP) ond nid oedd modd cynhyrchu cadwyn tystysgrif ymddiriedig sy'n cyd-fynd a'r set pinnau. Nid oes mod gwrthwneud torri pinio allweddi.
+mozilla-pkix-error-ca-cert-used-as-end-entity = Mae'r gweinydd yn defnyddio tystysgrif gydag estyniad cyfyngiadau sylfaenol sy'n ei ddynodi fel yr awdurdod tystysgrifo. Ar gyfer tystysgrifau sydd wedi eu rhyddhau'n briodol, ni ddylai hyn fod yn wir.
+mozilla-pkix-error-inadequate-key-size = Cyflwynodd y gweinydd dystysgrif sydd ag allwedd sy'n rhy fach i greu cysylltiad diogel.
+mozilla-pkix-error-v1-cert-used-as-ca = Defnyddiwyd tystysgrif X.509 fersiwn 1 nad yw'n angor ymddiriedaeth i gyhoeddi tystysgrif y wefan. Mae tystysgrifau X.509 fersiwn 1 yn anghymeradwy ac ni ddylent gael eu defnyddio i lofnodi tystysgrifau eraill.
+mozilla-pkix-error-not-yet-valid-certificate = Cyflwynodd y gweinydd dystysgrif nad yw eto'n ddilys.
+mozilla-pkix-error-not-yet-valid-issuer-certificate = Defnyddiwyd tystysgrif nad yw eto'n ddilys i gyhoeddi tystysgrif y gweinydd.
+mozilla-pkix-error-signature-algorithm-mismatch = Nid yw'r algorithm llofnod ym maes llofnod y dystysgrif yn cyd-fynd â'r algorithm ym maes signatureAlgorithm.
+mozilla-pkix-error-ocsp-response-for-cert-missing = Nid yw ymateb yr OCSP yn cynnwys statws y dystysgrif sy'n cael ei gwirio.
+mozilla-pkix-error-validity-too-long = Cyflwynodd y gweinydd dystysgrif sy'n ddilys am rhy hir.
+mozilla-pkix-error-required-tls-feature-missing = Mae'r nodwedd TLS angenrheidiol ar goll.
+mozilla-pkix-error-invalid-integer-encoding = Cyflwynodd y gweinydd dystysgrif sy'n cynnwys math annilys o amgodio integer. Mae'r rhesymau cyffredin yn cynnwys rhifau cyfresol negyddol, moduli RSA negyddol, ac amgodio nad ydynt eu hangen bellach.
+mozilla-pkix-error-empty-issuer-name = Cyflwynodd y gweinydd dystysgrif gydag enw cyhoeddwr penodol gwag.
+mozilla-pkix-error-additional-policy-constraint-failed = Methodd cyfyngiad polisi ychwanegol wrth ddilysu'r dystysgrif hon.
+mozilla-pkix-error-self-signed-cert = Nid oes modd ymddiried yn y dystysgrif am ei fod wedi ei hunanlofnodi.
diff --git a/l10n-cy/browser/browser/originControls.ftl b/l10n-cy/browser/browser/originControls.ftl
new file mode 100644
index 0000000000..4c7760462c
--- /dev/null
+++ b/l10n-cy/browser/browser/originControls.ftl
@@ -0,0 +1,50 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+## These strings appear in Origin Controls for Extensions.  Currently,
+## they are visible in the context menu for extension toolbar buttons,
+## and are used to inform the user how the extension can access their
+## data for the current website, and allow them to control it.
+
+origin-controls-no-access =
+    .label = Nid yw'r Estyniad yn Gallu Darllen na Newid Data
+origin-controls-options =
+    .label = Mae'r Estyniad yn Gallu Ddarllen a Newid Data:
+origin-controls-option-all-domains =
+    .label = Ar Pob Gwefan
+origin-controls-option-when-clicked =
+    .label = Dim ond Ar ôl Clicio
+# This string denotes an option that grants the extension access to
+# the current site whenever they visit it.
+# Variables:
+#   $domain (String) - The domain for which the access is granted.
+origin-controls-option-always-on =
+    .label = Caniatáu Bob Tro ar { $domain }
+
+## These strings are used to map Origin Controls states to user-friendly
+## messages. They currently appear in the unified extensions panel.
+
+origin-controls-state-no-access = Methu darllen na newid data ar y wefan hon
+origin-controls-state-always-on = Yn gallu darllen a newid data ar y wefan hon bob tro
+origin-controls-state-when-clicked = Mae angen caniatâd i ddarllen a newid data
+origin-controls-state-hover-run-visit-only = Rhedeg ar gyfer yr ymweliad hwn yn unig
+origin-controls-state-runnable-hover-open = Agor estyniad
+origin-controls-state-runnable-hover-run = Rhedeg estyniad
+origin-controls-state-temporary-access = Yn gallu darllen a newid data ar gyfer yr ymweliad hwn
+
+## Extension's toolbar button.
+## Variables:
+##   $extensionTitle (String) - Extension name or title message.
+
+origin-controls-toolbar-button =
+    .label = { $extensionTitle }
+    .tooltiptext = { $extensionTitle }
+# Extension's toolbar button when permission is needed.
+# Note that the new line is intentionally part of the tooltip.
+origin-controls-toolbar-button-permission-needed =
+    .label = { $extensionTitle }
+    .tooltiptext =
+        { $extensionTitle }
+        Angen cainatâd
diff --git a/l10n-cy/browser/browser/pageInfo.ftl b/l10n-cy/browser/browser/pageInfo.ftl
new file mode 100644
index 0000000000..c248c948f2
--- /dev/null
+++ b/l10n-cy/browser/browser/pageInfo.ftl
@@ -0,0 +1,277 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/. --
+
+page-info-window =
+    .style = width: 600px; min-height: 550px;
+
+copy =
+    .key = C
+menu-copy =
+    .label = Copïo
+    .accesskey = C
+
+select-all =
+    .key = A
+menu-select-all =
+    .label = Dewis Popeth
+    .accesskey = P
+
+close-dialog =
+    .key = w
+
+general-tab =
+    .label = Cyffredinol
+    .accesskey = C
+general-title =
+    .value = Teitl:
+general-url =
+    .value = Cyfeiriad:
+general-type =
+    .value = Math:
+general-mode =
+    .value = Modd Llunio:
+general-size =
+    .value = Maint:
+general-referrer =
+    .value = URL cyfeirio:
+general-modified =
+    .value = Newidiwyd:
+general-encoding =
+    .value = Amgodiad Testun:
+general-meta-name =
+    .label = Enw
+general-meta-content =
+    .label = Cynnwys
+
+media-tab =
+    .label = Cyfrwng
+    .accesskey = C
+media-location =
+    .value = Lleoliad:
+media-text =
+    .value = Testun Cysylltiedig:
+media-alt-header =
+    .label = Testun Arall
+media-address =
+    .label = Cyfeiriad
+media-type =
+    .label = Math
+media-size =
+    .label = Maint
+media-count =
+    .label = Cyfrif
+media-dimension =
+    .value = Maint:
+media-long-desc =
+    .value = Disgrifiad Hir:
+media-select-all =
+    .label = Dewis y Cyfan
+    .accesskey = D
+media-save-as =
+    .label = Cadw Fel…
+    .accesskey = A
+media-save-image-as =
+    .label = Cadw Fel…
+    .accesskey = e
+
+perm-tab =
+    .label = Caniatâd
+    .accesskey = C
+permissions-for =
+    .value = Caniatâd ar gyfer:
+
+security-tab =
+    .label = Diogelwch
+    .accesskey = D
+security-view =
+    .label = Darllen y Dystysgrif
+    .accesskey = D
+security-view-unknown = Anhysbys
+    .value = Anhysbys
+security-view-identity =
+    .value = Enw Gwefan
+security-view-identity-owner =
+    .value = Perchennog:
+security-view-identity-domain =
+    .value = Gwefan:
+security-view-identity-verifier =
+    .value = Gwiriwyd gan:
+security-view-identity-validity =
+    .value = Daw i ben ar:
+security-view-privacy =
+    .value = Preifatrwydd a Hanes
+
+security-view-privacy-history-value = A ydw i wedi ymweld â'r wefan hon cyn heddiw?
+security-view-privacy-sitedata-value = A yw'r wefan yma'n yn cadw gwybodaeth ar fy nghyfrifiadur?
+
+security-view-privacy-clearsitedata =
+    .label = Clirio Data Cwcis a Data
+    .accesskey = C
+
+security-view-privacy-passwords-value = A ydw i wedi cadw unrhyw gyfrineiriau ar gyfer y wefan yma?
+
+security-view-privacy-viewpasswords =
+    .label = Gweld y Cyfrineiriau wedi eu Cadw
+    .accesskey = w
+security-view-technical =
+    .value = Manylion Technegol
+
+help-button =
+    .label = Cymorth
+
+## These strings are used to tell the user if the website is storing cookies
+## and data on the users computer in the security tab of pageInfo
+## Variables:
+##   $value (number) - Amount of data being stored
+##   $unit (string) - The unit of data being stored (Usually KB)
+
+security-site-data-cookies = Ydy, cwcis a { $value } { $unit } o ddata gwefan
+security-site-data-only = Ydy, { $value } { $unit } o ddata gwefan
+
+security-site-data-cookies-only = Ydy, cwcis
+security-site-data-no = Na
+
+##
+
+image-size-unknown = Anhysbys
+page-info-not-specified =
+    .value = Heb ddiffinio
+not-set-alternative-text = Heb ddiffinio
+not-set-date = Heb ddiffinio
+media-img = Delwedd
+media-bg-img = Cefndir
+media-border-img = Ymyl
+media-list-img = Bwled
+media-cursor = Cyrchwr
+media-object = Gwrthych
+media-embed = Mewnblannu
+media-link = Eicon
+media-input = Mewnbwn
+media-video = Fideo
+media-audio = Sain
+saved-passwords-yes = Ydw
+saved-passwords-no = Na
+
+no-page-title =
+    .value = Tudalen heb Deitl:
+general-quirks-mode =
+    .value = Modd Quirks
+general-strict-mode =
+    .value = Modd cynnal safonau
+page-info-security-no-owner =
+    .value = Nid yw'r wefan yn darparu gwybodaeth am ei pherchnogaeth.
+media-select-folder = Dewis Ffolder i Gadw'r Delweddau
+media-unknown-not-cached =
+    .value = Anhysbys (heb ei storio dros dro)
+permissions-use-default =
+    .label = Defnyddio'r Rhagosodedig
+security-no-visits = Na
+
+# This string is used to display the number of meta tags
+# in the General Tab
+# Variables:
+#   $tags (number) - The number of meta tags
+general-meta-tags =
+    .value =
+        { $tags ->
+            [zero] Meta ({ $tags } tagiau)
+            [one] Meta (1 tag)
+            [two] Meta ({ $tags } dags)
+            [few] Meta ({ $tags } tag)
+            [many] Meta ({ $tags } tag)
+           *[other] Meta ({ $tags } tag)
+        }
+
+# This string is used to display the number of times
+# the user has visited the website prior
+# Variables:
+#   $visits (number) - The number of previous visits
+security-visits-number =
+    { $visits ->
+        [0] Na
+        [zero] Do, unwaith
+        [one] Do, { $visits } waith
+        [two] Do, { $visits } waith
+        [few] Do, { $visits } gwaith
+        [many] Do, { $visits } waith
+       *[other] Do, { $visits } gwaith
+    }
+
+# This string is used to display the size of a media file
+# Variables:
+#   $kb (number) - The size of an image in Kilobytes
+#   $bytes (number) - The size of an image in Bytes
+properties-general-size =
+    .value =
+        { $bytes ->
+            [zero] { $kb } KB ({ $bytes } beit)
+            [one] { $kb } KB ({ $bytes } beit)
+            [two] { $kb } KB ({ $bytes } beit)
+            [few] { $kb } KB ({ $bytes } beit)
+            [many] { $kb } KB ({ $bytes } beit)
+           *[other] { $kb } KB ({ $bytes } beit)
+        }
+
+# This string is used to display the type and number
+# of frames of a animated image
+# Variables:
+#   $type (string) - The type of a animated image
+#   $frames (number) - The number of frames in an animated image
+media-animated-image-type =
+    .value =
+        { $frames ->
+            [zero] Delwedd { $type } (animeiddio, { $frames } ffrâm)
+            [one] Delwedd { $type } (animeiddio, { $frames } ffrâm)
+            [two] Delwedd { $type } (animeiddio, { $frames } ffrâm)
+            [few] Delwedd { $type } (animeiddio, { $frames } ffrâm)
+            [many] Delwedd { $type } (animeiddio, { $frames } ffrâm)
+           *[other] Delwedd { $type } (animeiddio, { $frames } ffrâm)
+        }
+
+# This string is used to display the type of
+# an image
+# Variables:
+#   $type (string) - The type of an image
+media-image-type =
+    .value = Delwedd { $type }
+
+# This string is used to display the size of a scaled image
+# in both scaled and unscaled pixels
+# Variables:
+#   $dimx (number) - The horizontal size of an image
+#   $dimy (number) - The vertical size of an image
+#   $scaledx (number) - The scaled horizontal size of an image
+#   $scaledy (number) - The scaled vertical size of an image
+media-dimensions-scaled =
+    .value = { $dimx }px × { $dimy }px (graddio i { $scaledx }px × { $scaledy }px)
+
+# This string is used to display the size of an image in pixels
+# Variables:
+#   $dimx (number) - The horizontal size of an image
+#   $dimy (number) - The vertical size of an image
+media-dimensions =
+    .value = { $dimx }px × { $dimy }px
+
+# This string is used to display the size of a media
+# file in kilobytes
+# Variables:
+#   $size (number) - The size of the media file in kilobytes
+media-file-size = { $size } KB
+
+# This string is used to display the website name next to the
+# "Block Images" checkbox in the media tab
+# Variables:
+#   $website (string) - The website name
+media-block-image =
+    .label = Rhwystro Delweddau o { $website }
+    .accesskey = B
+
+# This string is used to display the URL of the website on top of the
+# pageInfo dialog box
+# Variables:
+#   $website (string) — The url of the website pageInfo is getting info for
+page-info-page =
+    .title = Gwyb. Tud. - { $website }
+page-info-frame =
+    .title = Gwyb. Ffrâm - { $website }
diff --git a/l10n-cy/browser/browser/panelUI.ftl b/l10n-cy/browser/browser/panelUI.ftl
new file mode 100644
index 0000000000..036d32e853
--- /dev/null
+++ b/l10n-cy/browser/browser/panelUI.ftl
@@ -0,0 +1,25 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+## Customization Menu
+
+# The overflow menu is the menu that appears if you click the chevron (>> button) in the location bar.
+customize-menu-unpin-from-overflowmenu =
+    .label = Dadbinio o'r Ddewislen Ychwanegol
+    .accesskey = D
+customize-menu-add-to-toolbar =
+    .label = Ychwanegu i'r Bar Offer
+    .accesskey = Y
+customize-menu-add-to-overflowmenu =
+    .label = Ychwanegu at y Ddewislen Ychwanegol
+    .accesskey = D
+
+## Forget Button
+
+# The forget button can be added to the toolbar or overflow menu via the cutomization menu.
+panic-button-thankyou-msg1 = Mae eich hanes diweddar wedi ei glirio.
+panic-button-thankyou-msg2 = Pori diogel!
+panic-button-thankyou-button =
+    .label = Diolch!
diff --git a/l10n-cy/browser/browser/panicButton.ftl b/l10n-cy/browser/browser/panicButton.ftl
new file mode 100644
index 0000000000..cf6d196f6e
--- /dev/null
+++ b/l10n-cy/browser/browser/panicButton.ftl
@@ -0,0 +1,31 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+panic-button-open-new-window = Agor Ffenestr glân newydd
+panic-button-undo-warning = Nid oes modd dadwneud y weithred.
+panic-button-forget-button =
+    .label = Anghofio!
+
+## These strings are combined to form a complete sentence starting with
+## panic-main-timeframe-desc. For example: "Forget the last: Five minutes".
+## Please ensure that this remains the case in the translation.
+
+panic-main-timeframe-desc = Anghofio'r olaf:
+panic-button-5min =
+    .label = Pum munud
+panic-button-2hr =
+    .label = Dwy awr
+panic-button-day =
+    .label = 24 awr
+
+## These strings are combined to form a complete sentence starting with
+## panic-button-action-desc. For example: "Proceeding will: Delete Recent Cookies".
+## Please ensure that this remains the case in the translation.
+## Note also that some strings include <strong> tags for emphasis on the
+## words "Cookies", "History", "Tabs" and "Windows". The translation should do the same.
+
+panic-button-action-desc = Bydd parhau yn:
+panic-button-delete-cookies = Dileu <strong>Cwcis</strong> Diweddar
+panic-button-delete-history = Dileu <strong>Hanes</strong> Diweddar
+panic-button-delete-tabs-and-windows = Cau pob <strong>Tab</strong> a <strong>Ffenestr</strong>
diff --git a/l10n-cy/browser/browser/places.ftl b/l10n-cy/browser/browser/places.ftl
new file mode 100644
index 0000000000..37d97c3645
--- /dev/null
+++ b/l10n-cy/browser/browser/places.ftl
@@ -0,0 +1,217 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this file,
+# You can obtain one at http://mozilla.org/MPL/2.0/.
+
+places-open =
+    .label = Agor
+    .accesskey = A
+places-open-in-tab =
+    .label = Agor mewn Tab Newydd
+    .accesskey = A
+places-open-in-container-tab =
+    .label = Agor mewn Tab Cynhwysydd Newydd
+    .accesskey = A
+places-open-all-bookmarks =
+    .label = Agor Pob Nod Tudalen
+    .accesskey = A
+places-open-all-in-tabs =
+    .label = Agor pob Tab
+    .accesskey = T
+places-open-in-window =
+    .label = Agor mewn Ffenestr Newydd
+    .accesskey = N
+places-open-in-private-window =
+    .label = Agor mewn Ffenestr Breifat Newydd
+    .accesskey = B
+places-add-bookmark =
+    .label = Ychwanegu Nod Tudalen…
+    .accesskey = N
+places-add-folder-contextmenu =
+    .label = Ychwanegu Ffolder…
+    .accesskey = F
+places-add-folder =
+    .label = Ychwanegu Ffolder…
+    .accesskey = o
+places-add-separator =
+    .label = Ychwanegu Ymwahanydd
+    .accesskey = Y
+places-view =
+    .label = Golwg
+    .accesskey = w
+places-by-date =
+    .label = Yn ôl Dyddiad
+    .accesskey = D
+places-by-site =
+    .label = Yn ôl Gwefan
+    .accesskey = G
+places-by-most-visited =
+    .label = Ymwelwyd Amlaf
+    .accesskey = A
+places-by-last-visited =
+    .label = Ymwelwyd Diwethaf
+    .accesskey = D
+places-by-day-and-site =
+    .label = Yn ôl Dyddiad a Gwefan
+    .accesskey = Y
+places-history-search =
+    .placeholder = Hanes chwilio
+places-history =
+    .aria-label = Hanes
+places-bookmarks-search =
+    .placeholder = Chwilio'r nodau tudalen
+places-delete-domain-data =
+    .label = Anghofio'r Wefan Hon
+    .accesskey = W
+places-sortby-name =
+    .label = Trefnu yn Ôl Enw
+    .accesskey = r
+# places-edit-bookmark and places-edit-generic will show one or the other and can have the same access key.
+places-edit-bookmark =
+    .label = Golygu Nod Tudalen…
+    .accesskey = G
+places-edit-generic =
+    .label = Golygu…
+    .accesskey = o
+places-edit-folder2 =
+    .label = Golygu Ffolder …
+    .accesskey = G
+places-delete-folder =
+    .label =
+        { $count ->
+            [1] Dileu Ffolder
+            [zero] Dileu Ffolderi
+            [one] Dileu Ffolder
+            [two] Dileu Ffolder
+            [few] Dileu Ffolder
+            [many] Dileu Ffolder
+           *[other] Dileu Ffolder
+        }
+    .accesskey = D
+# Managed bookmarks are created by an administrator and cannot be changed by the user.
+managed-bookmarks =
+    .label = Nodau Tudalen wedi'u rheoli
+# This label is used when a managed bookmarks folder doesn't have a name.
+managed-bookmarks-subfolder =
+    .label = Is-ffolder
+# This label is used for the "Other Bookmarks" folder that appears in the bookmarks toolbar.
+other-bookmarks-folder =
+    .label = Nodau Tudalen Eraill
+places-show-in-folder =
+    .label = Dangos mewn Ffolder
+    .accesskey = F
+# Variables:
+# $count (number) - The number of elements being selected for removal.
+places-delete-bookmark =
+    .label =
+        { $count ->
+            [1] Dileu Nod Tudalen
+            [zero] Dileu Nodau Tudalen
+            [one] Dileu Nod Tudalen
+            [two] Dileu Nod Tudalen
+            [few] Dileu Nod Tudalen
+            [many] Dileu Nod Tudalen
+           *[other] Dileu Nod Tudalen
+        }
+    .accesskey = D
+places-untag-bookmark =
+    .label = Tynnu Tag
+    .accesskey = T
+places-manage-bookmarks =
+    .label = Rheoli Nodau Tudalen
+    .accesskey = R
+places-forget-about-this-site-confirmation-title = Anghofio'r wefan hon
+# Variables:
+# $hostOrBaseDomain (string) - The base domain (or host in case there is no base domain) for which data is being removed
+places-forget-about-this-site-confirmation-message = Bydd y weithred hon yn dileu'r holl ddata sy'n gysylltiedig â { $hostOrBaseDomain } gan gynnwys hanes, cyfrineiriau, cwcis, storfa a dewisiadau cynnwys. Ydych chi'n siŵr eich bod chi am barhau?
+# Variables:
+# $hostOrBaseDomain (string) - The base domain (or host in case there is no base domain) for which data is being removed
+places-forget-about-this-site-confirmation-msg = Bydd y weithred hon yn dileu data sy'n gysylltiedig â { $hostOrBaseDomain } gan gynnwys hanes, cwcis, storfa a dewisiadau cynnwys. Ni fydd nodau tudalen a chyfrineiriau cysylltiedig yn cael eu dileu. Ydych chi'n siŵr eich bod am barhau?
+places-forget-about-this-site-forget = Anghofio
+places-library =
+    .title = Llyfrgell
+    .style = width:700px; height:500px;
+places-library2 =
+    .title = Llyfrgell
+    .style = min-width:700px; min-height:500px;
+places-library3 =
+    .title = Llyfrgell
+places-organize-button =
+    .label = Trefnu
+    .tooltiptext = Trefnu eich nodau tudalen
+    .accesskey = T
+places-organize-button-mac =
+    .label = Trefnu
+    .tooltiptext = Trefnu eich nodau tudalen
+places-file-close =
+    .label = Cau
+    .accesskey = C
+places-cmd-close =
+    .key = w
+places-view-button =
+    .label = Golygon
+    .tooltiptext = Newid eich golwg
+    .accesskey = G
+places-view-button-mac =
+    .label = Golygon
+    .tooltiptext = Newid eich golwg
+places-view-menu-columns =
+    .label = Dangos Colofnau
+    .accesskey = D
+places-view-menu-sort =
+    .label = Trefnu
+    .accesskey = r
+places-view-sort-unsorted =
+    .label = Didrefn
+    .accesskey = i
+places-view-sort-ascending =
+    .label = Trefnu A > Z
+    .accesskey = A
+places-view-sort-descending =
+    .label = Trefnu Z > A
+    .accesskey = Z
+places-maintenance-button =
+    .label = Mewnforio ac Allforio
+    .tooltiptext = Mewnforio a chadw eich nodau tudalen wrth gefn
+    .accesskey = M
+places-maintenance-button-mac =
+    .label = Mewnforio ac Allforio
+    .tooltiptext = Mewnforio a chadw eich nodau tudalen wrth gefn
+places-cmd-backup =
+    .label = Wrth Gefn…
+    .accesskey = W
+places-cmd-restore =
+    .label = Adfer
+    .accesskey = A
+places-cmd-restore-from-file =
+    .label = Dewis Ffeil…
+    .accesskey = D
+places-import-bookmarks-from-html =
+    .label = Mewnforio Nodau Tudalen o HTML…
+    .accesskey = i
+places-export-bookmarks-to-html =
+    .label = Allforio Nodau Tudalen i HTML…
+    .accesskey = H
+places-import-other-browser =
+    .label = Mewnforio Data o Borwr Arall…
+    .accesskey = A
+places-view-sort-col-name =
+    .label = Enw
+places-view-sort-col-tags =
+    .label = Tagiau
+places-view-sort-col-url =
+    .label = Lleoliad
+places-view-sort-col-most-recent-visit =
+    .label = Ymweliad Diweddaraf
+places-view-sort-col-visit-count =
+    .label = Cyfrif Ymweliadau
+places-view-sort-col-date-added =
+    .label = Ychwanegwyd
+places-view-sort-col-last-modified =
+    .label = Newidwyd Ddiwethaf
+places-cmd-find-key =
+    .key = f
+places-back-button =
+    .tooltiptext = Mynd nôl
+places-forward-button =
+    .tooltiptext = Mynd ymlaen
+places-details-pane-select-an-item-description = Dewis eitem i'w gweld a golygu ei phriodweddau
diff --git a/l10n-cy/browser/browser/policies/policies-descriptions.ftl b/l10n-cy/browser/browser/policies/policies-descriptions.ftl
new file mode 100644
index 0000000000..9d8780ce0d
--- /dev/null
+++ b/l10n-cy/browser/browser/policies/policies-descriptions.ftl
@@ -0,0 +1,125 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+## The Enterprise Policies feature is aimed at system administrators
+## who want to deploy these settings across several Firefox installations
+## all at once. This is traditionally done through the Windows Group Policy
+## feature, but the system also supports other forms of deployment.
+## These are short descriptions for individual policies, to be displayed
+## in the documentation section in about:policies.
+
+policy-3rdparty = Gosodwch bolisïau y gall WebExtensions gael mynediad atyn nhw trwy chrome.storage.managed.
+policy-AllowedDomainsForApps = Diffinio parthau sy'n cael eu caniatáu i gael mynediad at Google Workpace.
+policy-AppAutoUpdate = Galluogi neu analluogi diweddaru rhaglen yn awtomatig.
+policy-AppUpdatePin = Rhwystro { -brand-short-name } rhag cael ei ddiweddaru y tu hwnt i'r fersiwn penodedig.
+policy-AppUpdateURL = Gosod URL diweddaru ap cyfaddas.
+policy-Authentication = Ffurfweddu dilysu integredig ar gyfer gwefannau sy'n ei gefnogi.
+policy-AutoLaunchProtocolsFromOrigins = Diffiniwch restr o brotocolau allanol y mae modd eu defnyddio o darddiad rhestredig heb annog y defnyddiwr.
+policy-BackgroundAppUpdate2 = Galluogi neu analluogi'r diweddarydd cefndir.
+policy-BlockAboutAddons = Rhwystro mynediad at y Rheolwr Ychwanegion (about:addons)
+policy-BlockAboutConfig = Rhwystro mynediad at y dudalen about:config.
+policy-BlockAboutProfiles = Rhwystro mynediad at y dudalen about:profiles.
+policy-BlockAboutSupport = Rhwystro mynediad at y dudalen about:support.
+policy-Bookmarks = Creu nodau tudalen yn y bar offer Nodau Tudalen, dewislen Nodau Tudalen neu ffolder penodol o'u mewn.
+policy-CaptivePortal = Galluogi neu analluogi'r cymorth porth caeth.
+policy-CertificatesDescription = Ychwanegu tystysgrifau neu ddefnyddio tystysgrifau mewnol.
+policy-Cookies = Caniatáu neu wrthod i wefannau osod cwcis.
+policy-DisabledCiphers = Analluogi seifferau.
+policy-DefaultDownloadDirectory = Gosod y cyfeiriadur llwytho i lawr rhagosodedig.
+policy-DisableAppUpdate = Rhwystro'r wefan rhag diweddaru.
+policy-DisableBuiltinPDFViewer = Analluogi PDF.js, y dangosydd PDF mewnol yn { -brand-short-name }.
+policy-DisableDefaultBrowserAgent = Atal asiant y porwr rhagosodedig rhag cymryd unrhyw gamau. Dim ond yn berthnasol i Windows; nid oes gan lwyfannau eraill yr asiant.
+policy-DisableDeveloperTools = Rhwystro mynediad at yr offer datblygwr.
+policy-DisableFeedbackCommands = Analluogi gorchmynion rhag anfon adborth o'r ddewislen Cymorth (Cyflwyno Adborth ac Adrodd ar Wefan Dwyllodrus).
+policy-DisableFirefoxAccounts = Analluogi gwasanaethau'n seiliedig ar { -fxaccount-brand-name }, gan gynnwys Sync.
+# Firefox Screenshots is the name of the feature, and should not be translated.
+policy-DisableFirefoxScreenshots = Analluogi nodwedd Firefox Screenshots.
+policy-DisableFirefoxStudies = Rhwystro { -brand-short-name } rhag rhedeg astudiaethau.
+policy-DisableForgetButton = Rhwystro mynediad at y botwm Anghofio.
+policy-DisableFormHistory = Peidio cofio chwilio a hanes ffurflenni.
+policy-DisablePrimaryPasswordCreation = Os yn wir, nid oes modd creu Prif Cyfrinair.
+policy-DisablePasswordReveal = Peidiwch â gadael i gyfrineiriau gael eu datgelu mewn mewngofnodi sydd wedi'u cadw.
+policy-DisablePocket = Analluogi'r nodwedd i gadw tudalennau gwe i Pocket.
+policy-DisablePrivateBrowsing = Analluogi Pori Preifat.
+policy-DisableProfileImport = Analluogi'r gorchymyn dewislen i fewnforio data o borwr arall.
+policy-DisableProfileRefresh = Analluogi botwm Adnewyddu { -brand-short-name } yn nhudalen about:support
+policy-DisableSafeMode = Analluogi'r nodwedd i ailgychwyn yn y Modd Diogel. Sylw: dim ond drwy'r Polisi Grŵp y mae modd analluogi'r defnydd o fysell Shift i fynd i'r modd Diogel.
+policy-DisableSecurityBypass = Rhwystro'r defnyddiwr rhag osgoi rhai rhybuddion diogelwch.
+policy-DisableSetAsDesktopBackground = Analluogi'r dewislen gorchymyn Gosod fel Delwedd Cefndir ar gyfer delwddau.
+policy-DisableSystemAddonUpdate = Rhwystro'r porwr rhag gosod a diweddaru ychwanegion y system.
+policy-DisableTelemetry = Diffodd Telemetreg
+policy-DisableThirdPartyModuleBlocking = Rhwystrwch y defnyddiwr rhag rhwystro modiwlau trydydd parti sy'n cael eu chwistrellu i'r broses { -brand-short-name }.
+policy-DisplayBookmarksToolbar = Dangos y Bar Offer Nodau Tudalen drwy ragosodiad.
+policy-DisplayMenuBar = Dangos y Bar Dewislen drwy ragosodiad
+policy-DNSOverHTTPS = Ffurfweddu DNS dros HTTPS.
+policy-DontCheckDefaultBrowser = Analluogwch gwirio am y porwr rhagosodedig wrth gychwyn.
+policy-DownloadDirectory = Gosod a chloi'r cyfeiriadur llwytho i lawr.
+# “lock” means that the user won’t be able to change this setting
+policy-EnableTrackingProtection = Galluogi neu analluogi Rhwystro Cynnwys ac o ddewis ei gloi.
+# “lock” means that the user won’t be able to change this setting
+policy-EncryptedMediaExtensions = Galluogi neu Analluogi Estyniadau Cyfryngau Amgryptiedig ac o ddewis eu cloi.
+policy-ExemptDomainFileTypePairsFromFileTypeDownloadWarnings = Analluogi rhybuddion yn seiliedig ar estyniad ffeil ar gyfer mathau penodol o ffeiliau ar barthau.
+# A “locked” extension can’t be disabled or removed by the user. This policy
+# takes 3 keys (“Install”, ”Uninstall”, ”Locked”), you can either keep them in
+# English or translate them as verbs.
+policy-Extensions = Gosod, dadosod neu gloi estyniadau. Mae'r dewis gosod yn cymryd URL neu lwybrau fel paramedrau. Mae'r dewisiadau Dadosod a Chloi yn cymryd dynodiad estyniadau.
+policy-ExtensionSettings = Rheoli pob agwedd o osod estyniad.
+policy-ExtensionUpdate = Galluogi neu analluogi diweddaru estyniadau'n awtomatig.
+policy-FirefoxHome = Ffurfweddu Firefox Home.
+policy-FirefoxHome2 = Ffurfweddu { -firefox-home-brand-name }.
+policy-FlashPlugin = Caniatáu neu wrthod defnydd o'r ychwanegyn Flash.
+policy-GoToIntranetSiteForSingleWordEntryInAddressBar = Gorfodi llywio safle mewnrwyd yn uniongyrchol yn lle chwilio wrth deipio gair yn y bar cyfeiriad.
+policy-Handlers = Ffurfweddu trinwyr rhaglenni rhagosodedig.
+policy-HardwareAcceleration = Os gau, diffodd cyflymu caledwedd.
+# “lock” means that the user won’t be able to change this setting
+policy-Homepage = Gosod ac o ddewis cloi'r dudalen cartref.
+policy-InstallAddonsPermission = Caniatáu i rai gwefannau i osod ychwanegion
+policy-LegacyProfiles = Analluoga'r nodwedd gan orfodi proffil ar wahân ar gyfer pob gosodiad
+
+## Do not translate "SameSite", it's the name of a cookie attribute.
+
+policy-LegacySameSiteCookieBehaviorEnabled = Galluogi'r gosodiad rhagosodedig ymddygiadol cwci SameSite blaenorol.
+policy-LegacySameSiteCookieBehaviorEnabledForDomainList = Dychwelyd at ymddygiad blaenorol SameSite ar gyfer cwcis ar wefannau penodol.
+
+##
+
+policy-LocalFileLinks = Caniatáu i wefannau penodol gysylltu i ffeiliau lleol.
+policy-ManagedBookmarks = Yn ffurfweddu rhestr o nodau tudalen sy'n cael eu rheoli gan weinyddwr nad yw'r defnyddiwr yn gallu eu newid.
+policy-ManualAppUpdateOnly = Caniatáu diweddariadau â llaw yn unig a pheidio â hysbysu'r defnyddiwr am ddiweddariadau.
+policy-PrimaryPassword = Ei gwneud yn ofynnol neu atal defnyddio Prif Gyfrinair.
+policy-NetworkPrediction = Galluogi neu analluoga rhagfynegiad rhwydwaith (rhagosod ymlaen DNS).
+policy-NewTabPage = Galluogi neu analluogi tudalen Tab Newydd.
+policy-NoDefaultBookmarks = Analluogi creu nodau tudalen rhagosodedig wedi eu pecynnu gyda { -brand-short-name }, a'r Nodau Tudalen Clyfar (Ymwelwyd Amlaf, Tagiau Diweddar). Sylw: mae'r polisi hwn ddim ond yn effeithiol os yw'n cael ei ddefnyddio cyn rhedeg y proffil y tro cyntaf.
+policy-OfferToSaveLogins = Gorfodi'r gosodiad i ganiatáu i { -brand-short-name } gynnig cofio mewngofnodion a chyfrineiriau wedi eu cadw. Mae gwerthoedd gwir a gau'n cael eu derbyn.
+policy-OfferToSaveLoginsDefault = Gosodwch y gwerth ragosodedig ar gyfer caniatáu i { -brand-short-name } gynnig cofio mewngofnodion a chyfrineiriau wedi'u cadw. Mae gwerthoedd gwir a ffug yn cael eu derbyn.
+policy-OverrideFirstRunPage = Diystyru y dudalen rhediad gyntaf. Gosod y polisi hwn i gwag os ydych am analluogi'r dudalen rhediad cyntaf.
+policy-OverridePostUpdatePage = Diystyru'r dudalen ôl ddiweddaru "Beth sy'n Newydd". Gosodwch y polisi hwn i gwag os hoffech chi analluogi'r dudalen ôl ddiweddaru.
+policy-PasswordManagerEnabled = Galluogi cadw cyfrineiriau i'r rheolwr cyfrinair.
+policy-PasswordManagerExceptions = Rhwystro { -brand-short-name } rhag cadw cyfrineiriau ar gyfer gwefannau penodol.
+# PDF.js and PDF should not be translated
+policy-PDFjs = Analluogwch neu ffurfweddu PDF.js, y darllenydd PDF mewnol yn { -brand-short-name }.
+policy-Permissions2 = Ffurfweddwch y caniatâd ar gyfer camera, meicroffon, lleoliadau, hysbysiadau ac awtochwarae.
+policy-PictureInPicture = Galluogi neu analluogi Llun-mewn-Llun.
+policy-PopupBlocking = Caniatáu rhai gwefannau i ddangos llamlenni drwy ragosodiad.
+policy-Preferences = Gosod a chloi gwerth is-set o ddewisiadau.
+policy-PromptForDownloadLocation = Gofynnwch ble i gadw ffeiliau wrth eu llwytho i lawr.
+policy-Proxy = Ffurfweddu gosodiadau eilydd
+policy-RequestedLocales = Gosodwch y rhestr o locales gofynnol ar gyfer y rhaglen yn ôl eich trefn dewis.
+policy-SanitizeOnShutdown2 = Clirio data llywio wrth gau.
+policy-SearchBar = Gosod y lleoliad ragosodedig y bar chwilio. Mae'r defnyddiwr dal yn cael ei gyfaddasu.
+policy-SearchEngines = Ffurfweddu gosodiadau peiriannau chwilio. Dim ond yn y fersiwn Extended Support Release (ESR) mae'r polisi hwn ar gael.
+policy-SearchSuggestEnabled = Galluogi neu analluogi awgrymiadau chwilio.
+# For more information, see https://developer.mozilla.org/en-US/docs/Mozilla/Projects/NSS/PKCS11/Module_Installation
+policy-SecurityDevices = Gosod modiwlau PKCS #11.
+policy-ShowHomeButton = Dangos y botwm cartref ar y bar offer.
+policy-SSLVersionMax = Gosodwch y fersiwn SSL uchaf.
+policy-SSLVersionMin = Gosodwch y fersiwn SSL lleiaf.
+policy-StartDownloadsInTempDirectory = Gorfodi llwytho i lawr i gychwyn mewn lleoliad lleol, dros dro yn hytrach na'r cyfeiriadur llwytho i lawr rhagosodedig.
+policy-SupportMenu = Ychwanegu eitem ddewislen cymorth cyfaddas i'r ddewislen cymorth.
+policy-UserMessaging = Peidio â dangos rhai negeseuon i'r defnyddiwr.
+policy-UseSystemPrintDialog = Argraffu gan ddefnyddio deialog argraffu'r system.
+# “format” refers to the format used for the value of this policy.
+policy-WebsiteFilter = Rhwystro gwefannau rhag derbyn ymweliadau. Gw. dogfennaeth am ragor o wybodaeth ar y fformat.
+policy-Windows10SSO = Caniatáu mewngofnodiad unigol ar gyfer cyfrifon Microsoft, gwaith ac ysgol.
diff --git a/l10n-cy/browser/browser/preferences/addEngine.ftl b/l10n-cy/browser/browser/preferences/addEngine.ftl
new file mode 100644
index 0000000000..036ffb8617
--- /dev/null
+++ b/l10n-cy/browser/browser/preferences/addEngine.ftl
@@ -0,0 +1,26 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+add-engine-window =
+    .title = Ychwanegu Peiriant Chwilio
+    .style = width: 32em;
+
+add-engine-window2 =
+    .title = Ychwanegu Peiriant Chwilio
+    .style = min-width: 32em;
+
+add-engine-button = Ychwanegu Peiriant Cyfaddas
+
+add-engine-name = Enw peiriant chwilio
+
+add-engine-alias = Enw arall
+
+add-engine-url = URL y peiriant, defnyddiwch %s yn lle'r term chwilio
+
+add-engine-dialog =
+    .buttonlabelaccept = Ychwanegu Peiriant
+    .buttonaccesskeyaccept = P
+
+engine-name-exists = Mae peiriant o'r enw yna'n bodoli eisoes.
+engine-alias-exists = Mae peiriant o'r enw arall yna'n bodoli eisoes.
diff --git a/l10n-cy/browser/browser/preferences/applicationManager.ftl b/l10n-cy/browser/browser/preferences/applicationManager.ftl
new file mode 100644
index 0000000000..f912fe73c3
--- /dev/null
+++ b/l10n-cy/browser/browser/preferences/applicationManager.ftl
@@ -0,0 +1,29 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+app-manager-window =
+    .title = Manylion y rhaglen
+    .style = width: 30em; min-height: 20em;
+
+app-manager-window2 =
+    .title = Manylion y rhaglen
+    .style = min-width: 30em; min-height: 20em;
+
+app-manager-remove =
+    .label = Tynnu
+    .accesskey = T
+
+# Variables:
+#   $type (String) - the URI scheme of the link (e.g. mailto:)
+app-manager-handle-protocol = Mae modd defnyddio'r rhaglenni canlynol i drin { $type } dolen.
+
+# Variables:
+#   $type (String) - the MIME type (e.g. application/binary)
+app-manager-handle-file = Mae modd defnyddio'r rhaglenni canlynol i drin Cynnwys { $type }.
+
+## These strings are followed, on a new line,
+## by the URL or path of the application.
+
+app-manager-web-app-info = Mae'r rhaglen gwe yma wedi ei weini yn:
+app-manager-local-app-info = Mae'r rhaglen wedi ei lleoli yn:
diff --git a/l10n-cy/browser/browser/preferences/blocklists.ftl b/l10n-cy/browser/browser/preferences/blocklists.ftl
new file mode 100644
index 0000000000..fb379e78a1
--- /dev/null
+++ b/l10n-cy/browser/browser/preferences/blocklists.ftl
@@ -0,0 +1,37 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+blocklist-window =
+    .title = Rhestrau Rhwystro
+    .style = width: 55em
+
+blocklist-window2 =
+    .title = Rhestrau Rhwystro
+    .style = min-width: 55em
+
+blocklist-description = Dewis y rhestr mae { -brand-short-name } yn ei defnyddio i atal tracio ar-lein. Rhestrau'n cael eu darparu gan <a data-l10n-name="disconnect-link" title="Disconnect"> Datgysylltu</a>.
+blocklist-close-key =
+    .key = w
+
+blocklist-treehead-list =
+    .label = Rhestr
+
+blocklist-dialog =
+    .buttonlabelaccept = Cadw Newidiadau
+    .buttonaccesskeyaccept = N
+
+
+# This template constructs the name of the block list in the block lists dialog.
+# It combines the list name and description.
+# e.g. "Standard (Recommended). This list does a pretty good job."
+#
+# Variables:
+#   $listName {string, "Standard (Recommended)."} - List name.
+#   $description {string, "This list does a pretty good job."} - Description of the list.
+blocklist-item-list-template = { $listName } { $description }
+
+blocklist-item-moz-std-listName = Rhestr rhwystro Lefel 1 (Argymell).
+blocklist-item-moz-std-description = Mae'n caniatáu rhai tracwyr fel bod llai o wefannau yn torri.
+blocklist-item-moz-full-listName = Rhestr rhwystro Lefel 2.
+blocklist-item-moz-full-description = Yn rhwystro pob traciwr wedi'u canfod. Efallai na fydd rhai gwefannau neu gynnwys yn llwytho'n iawn.
diff --git a/l10n-cy/browser/browser/preferences/clearSiteData.ftl b/l10n-cy/browser/browser/preferences/clearSiteData.ftl
new file mode 100644
index 0000000000..36f5824468
--- /dev/null
+++ b/l10n-cy/browser/browser/preferences/clearSiteData.ftl
@@ -0,0 +1,60 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+clear-site-data-window =
+    .title = Clirio Data
+    .style = width: 35em
+
+clear-site-data-window2 =
+    .title = Clirio Data
+    .style = min-width: 35em
+
+clear-site-data-description = Gall glirio'r oll gwcis a data gwefan wedi eu cadw gan { -brand-short-name } eich allgofnodi o wefannau a thynnu cynnwys all-lein gwe. Ni fydd clirio data storfa dros dro yn effeithio ar eich mewngofnodion.
+
+clear-site-data-close-key =
+    .key = w
+
+# The parameters in parentheses in this string describe disk usage
+# in the format ($amount $unit), e.g. "Cookies and Site Data (24 KB)"
+# Variables:
+#   $amount (Number) - Amount of site data currently stored on disk
+#   $unit (String) - Abbreviation of the unit that $amount is in, e.g. "MB"
+clear-site-data-cookies-with-data =
+    .label = Cwcis a Data Gwefan ({ $amount } { $unit })
+    .accesskey = C
+
+# This string is a placeholder for while the data used to fill
+# clear-site-data-cookies-with-data is loading. This placeholder is usually
+# only shown for a very short time (< 1s), so it should be very similar
+# or the same as clear-site-data-cookies-with-data (except the amount and unit),
+# to avoid flickering.
+clear-site-data-cookies-empty =
+    .label = Cwcis a Data Gwefan
+    .accesskey = C
+
+clear-site-data-cookies-info = Efallai y cewch eich allgofnodi os fydd wedi ei glirio
+
+# The parameters in parentheses in this string describe disk usage
+# in the format ($amount $unit), e.g. "Cached Web Content (24 KB)"
+# Variables:
+#   $amount (Number) - Amount of cache currently stored on disk
+#   $unit (String) - Abbreviation of the unit that $amount is in, e.g. "MB"
+clear-site-data-cache-with-data =
+    .label = Cynnwys Gwe wedi'i Storio Dros Dro ({ $amount } { $unit })
+    .accesskey = S
+
+# This string is a placeholder for while the data used to fill
+# clear-site-data-cache-with-data is loading. This placeholder is usually
+# only shown for a very short time (< 1s), so it should be very similar
+# or the same as clear-site-data-cache-with-data (except the amount and unit),
+# to avoid flickering.
+clear-site-data-cache-empty =
+    .label = Cynnwys Gwe wedi ei Storio Dros Dro
+    .accesskey = S
+
+clear-site-data-cache-info = Bydd angen i wefannau ail lwytho delweddau a data
+
+clear-site-data-dialog =
+    .buttonlabelaccept = Clirio
+    .buttonaccesskeyaccept = l
diff --git a/l10n-cy/browser/browser/preferences/colors.ftl b/l10n-cy/browser/browser/preferences/colors.ftl
new file mode 100644
index 0000000000..d3a2b6ab1f
--- /dev/null
+++ b/l10n-cy/browser/browser/preferences/colors.ftl
@@ -0,0 +1,56 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+colors-window =
+    .title = Lliwiau
+    .style =
+        { PLATFORM() ->
+            [macos] width: 41em
+           *[other] width: 38em
+        }
+
+colors-dialog =
+    .title = Lliwiau
+    .style = width: 41em;
+
+colors-dialog2 =
+    .title = Lliwiau
+    .style = min-width: 41em;
+
+colors-close-key =
+    .key = w
+
+colors-page-override = Anwybyddu'r lliwiau sy'n cael eu pennu gan y dudalen gan ddefnyddio fy newis i uchod
+    .accesskey = A
+
+colors-page-override-option-always =
+    .label = Bob tro
+colors-page-override-option-auto =
+    .label = Dim ond y themâu Cyferbyniad Uchel
+colors-page-override-option-never =
+    .label = Byth
+
+colors-text-and-background = Testun a Chefndir
+
+colors-text-header = Testun
+    .accesskey = T
+
+colors-background = Cefndir
+    .accesskey = C
+
+colors-use-system =
+    .label = Defnyddio lliwiau'r system
+    .accesskey = s
+
+colors-underline-links =
+    .label = Tanlinellu dolenni
+    .accesskey = d
+
+colors-links-header = Lliw Dolenni
+
+colors-unvisited-links = Dolenni heb gael Ymweliad
+    .accesskey = D
+
+colors-visited-links = Dolenni wedi cael Ymweliad
+    .accesskey = w
diff --git a/l10n-cy/browser/browser/preferences/connection.ftl b/l10n-cy/browser/browser/preferences/connection.ftl
new file mode 100644
index 0000000000..b0f029fcfb
--- /dev/null
+++ b/l10n-cy/browser/browser/preferences/connection.ftl
@@ -0,0 +1,109 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+connection-window =
+    .title = Gosodiadau Cysylltu
+    .style =
+        { PLATFORM() ->
+            [macos] width: 44em
+           *[other] width: 49em
+        }
+
+connection-window2 =
+    .title = Gosodiadau Cysylltu
+    .style =
+        { PLATFORM() ->
+            [macos] min-width: 44em
+           *[other] min-width: 49em
+        }
+
+connection-close-key =
+    .key = w
+
+connection-disable-extension =
+    .label = Analluogi Estyniad
+
+connection-proxy-configure = Ffurfweddu Mynediad Dirprwy i'r Rhyngrwyd
+
+connection-proxy-option-no =
+    .label = Dim dirprwy
+    .accesskey = D
+connection-proxy-option-system =
+    .label = Defnyddio gosodiadau dirprwyol y system
+    .accesskey = g
+connection-proxy-option-auto =
+    .label = Awto-ganfod gosodiadau dirprwyol ar gyfer y rhwydwaith
+    .accesskey = r
+connection-proxy-option-manual =
+    .label = Ffurfweddiad dirprwyo â llaw
+    .accesskey = l
+
+connection-proxy-http = Dirprwy yr HTTP
+    .accesskey = H
+connection-proxy-http-port = Porth
+    .accesskey = P
+connection-proxy-https-sharing =
+    .label = Defnyddio'r dirprwy yma hefyd ar gyfer HTTPS
+    .accesskey = D
+
+connection-proxy-https = Dirprwy HTTPS:
+    .accesskey = D
+connection-proxy-ssl-port = Porth
+    .accesskey = o
+
+connection-proxy-socks = Gwesteiwr SOCKS v5
+    .accesskey = G
+connection-proxy-socks-port = Porth
+    .accesskey = t
+
+connection-proxy-socks4 =
+    .label = SOCKS v4
+    .accesskey = K
+connection-proxy-socks5 =
+    .label = SOCKS v5
+    .accesskey = v
+connection-proxy-noproxy = Dim Dirprwy ar gyfer
+    .accesskey = m
+
+connection-proxy-noproxy-desc = Esiampl: .mozilla.org, .net.nz, 192.168.1.0/24
+
+# Do not translate "localhost", "127.0.0.1/8" and "::1". (You can translate "and".)
+connection-proxy-noproxy-localhost-desc-2 = Nid yw cysylltiadau â localhost, 127.0.0.1/8, a ::1 byth yn cael eu dirprwyo.
+
+connection-proxy-autotype =
+    .label = URL ffurfweddu dirprwy yn awtomatig
+    .accesskey = U
+
+connection-proxy-reload =
+    .label = Ail-lwytho
+    .accesskey = i
+
+connection-proxy-autologin =
+    .label = Peidio gofyn am ddilysiad os yw'r cyfrinair wedi ei gadw
+    .accesskey = d
+    .tooltip = Mae'r dewis hwn yn eich dilysu'n dawel i ddirprwyon rydych wedi eu cadw eu manylion ar eu cyfer. Byddwn yn gofyn os bydd y dilysiad yn methu.
+
+connection-proxy-socks-remote-dns =
+    .label = DNS dirprwyol wrth ddefnyddio SOCKS v5
+    .accesskey = d
+
+connection-dns-over-https =
+    .label = Galluogi DNS dros HTTPS
+    .accesskey = D
+
+connection-dns-over-https-url-resolver = Defnyddio'r Darparwr
+    .accesskey = D
+
+# Variables:
+#   $name (String) - Display name or URL for the DNS over HTTPS provider
+connection-dns-over-https-url-item-default =
+    .label = { $name } Rhagosodedig
+    .tooltiptext = Defnyddiwch yr URL rhagosodedig i ddatrys DNS dros HTTPS
+
+connection-dns-over-https-url-custom =
+    .label = Cyfaddasu
+    .accesskey = C
+    .tooltiptext = Rhowch eich hoff URL ar gyfer datrys DNS dros HTTPS
+
+connection-dns-over-https-custom-label = Cyfaddasu
diff --git a/l10n-cy/browser/browser/preferences/containers.ftl b/l10n-cy/browser/browser/preferences/containers.ftl
new file mode 100644
index 0000000000..18364f0129
--- /dev/null
+++ b/l10n-cy/browser/browser/preferences/containers.ftl
@@ -0,0 +1,102 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+containers-window-new =
+    .title = Ychwanegu Cynhwysydd Newydd
+    .style = width: 45em
+# Variables
+#   $name (String) - Name of the container
+containers-window-update-settings =
+    .title = Dewisiadau Cynwysyddion { $name }
+    .style = width: 45em
+
+containers-window-new2 =
+    .title = Ychwanegu Cynhwysydd Newydd
+    .style = min-width: 45em
+# Variables
+#   $name (String) - Name of the container
+containers-window-update-settings2 =
+    .title = Dewisiadau Cynwysyddion { $name }
+    .style = min-width: 45em
+
+containers-window-close =
+    .key = w
+
+# This is a term to store style to be applied
+# on the three labels in the containers add/edit dialog:
+#   - name
+#   - icon
+#   - color
+#
+# Using this term and referencing it in the `.style` attribute
+# of the three messages ensures that all three labels
+# will be aligned correctly.
+-containers-labels-style = min-width: 4rem
+
+containers-name-label = Enw
+    .accesskey = E
+    .style = { -containers-labels-style }
+
+containers-name-text =
+    .placeholder = Rhowch enw cynhwysydd
+
+containers-icon-label = Eicon
+    .accesskey = E
+    .style = { -containers-labels-style }
+
+containers-color-label = Lliw
+    .accesskey = L
+    .style = { -containers-labels-style }
+
+containers-dialog =
+    .buttonlabelaccept = Gorffen
+    .buttonaccesskeyaccept = G
+
+containers-color-blue =
+    .label = Glas
+containers-color-turquoise =
+    .label = Glaswyrdd
+containers-color-green =
+    .label = Gwyrdd
+containers-color-yellow =
+    .label = Melyn
+containers-color-orange =
+    .label = Oren
+containers-color-red =
+    .label = Coch
+containers-color-pink =
+    .label = Pinc
+containers-color-purple =
+    .label = Porffor
+containers-color-toolbar =
+    .label = Cydweddu'r bar offer
+
+containers-icon-fence =
+    .label = Ffens
+containers-icon-fingerprint =
+    .label = Bysbrint
+containers-icon-briefcase =
+    .label = Bag Dogfennau
+# String represents a money sign but currently uses a dollar sign
+# so don't change to local currency. See Bug 1291672.
+containers-icon-dollar =
+    .label = Arwydd dollar
+containers-icon-cart =
+    .label = Cart siopa
+containers-icon-circle =
+    .label = Dot
+containers-icon-vacation =
+    .label = Gwyliau
+containers-icon-gift =
+    .label = Rhodd
+containers-icon-food =
+    .label = Bwyd
+containers-icon-fruit =
+    .label = Ffrwythau
+containers-icon-pet =
+    .label = Anifail Anwes
+containers-icon-tree =
+    .label = Coeden
+containers-icon-chill =
+    .label = Ymlacio
diff --git a/l10n-cy/browser/browser/preferences/fonts.ftl b/l10n-cy/browser/browser/preferences/fonts.ftl
new file mode 100644
index 0000000000..8c0a5d9c45
--- /dev/null
+++ b/l10n-cy/browser/browser/preferences/fonts.ftl
@@ -0,0 +1,121 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+fonts-window =
+    .title = Ffontiau
+
+fonts-window-close =
+    .key = w
+
+## Font groups by language
+
+fonts-langgroup-header = Ffont ar gyfer
+    .accesskey = F
+
+fonts-langgroup-arabic =
+    .label = Arabaidd
+fonts-langgroup-armenian =
+    .label = Armeneg
+fonts-langgroup-bengali =
+    .label = Bengaleg
+fonts-langgroup-simpl-chinese =
+    .label = Tsieinëeg Syml
+fonts-langgroup-trad-chinese-hk =
+    .label = Tsieinëeg Traddodiadol (Hong Kong)
+fonts-langgroup-trad-chinese =
+    .label = Tsieinëeg Traddodiadol (Taiwan)
+fonts-langgroup-cyrillic =
+    .label = Cyrilig
+fonts-langgroup-devanagari =
+    .label = Devanagari
+fonts-langgroup-ethiopic =
+    .label = Ethiopeg
+fonts-langgroup-georgian =
+    .label = Georgeg
+fonts-langgroup-el =
+    .label = Groeg
+fonts-langgroup-gujarati =
+    .label = Gwjarati
+fonts-langgroup-gurmukhi =
+    .label = Gurmukhi
+fonts-langgroup-japanese =
+    .label = Japanëeg
+fonts-langgroup-hebrew =
+    .label = Hebraeg
+fonts-langgroup-kannada =
+    .label = Kannada
+fonts-langgroup-khmer =
+    .label = Khmer
+fonts-langgroup-korean =
+    .label = Corëeg
+# Translate "Latin" as the name of Latin (Roman) script, not as the name of the Latin language.
+fonts-langgroup-latin =
+    .label = Lladin
+fonts-langgroup-malayalam =
+    .label = Malaialam
+fonts-langgroup-math =
+    .label = Mathemateg
+fonts-langgroup-odia =
+    .label = Odia
+fonts-langgroup-sinhala =
+    .label = Sinhala
+fonts-langgroup-tamil =
+    .label = Tamileg
+fonts-langgroup-telugu =
+    .label = Telugu
+fonts-langgroup-thai =
+    .label = Thai
+fonts-langgroup-tibetan =
+    .label = Tibeteg
+fonts-langgroup-canadian =
+    .label = Unified Canadian Syllabary
+fonts-langgroup-other =
+    .label = Systemau Ysgrifennu Eraill
+
+## Default fonts and their sizes
+
+fonts-proportional-header = Cyfrannol
+    .accesskey = y
+
+fonts-default-serif =
+    .label = Serif
+fonts-default-sans-serif =
+    .label = Sans Serif
+
+fonts-proportional-size = Maint
+    .accesskey = M
+
+fonts-serif = Serif
+    .accesskey = S
+
+fonts-sans-serif = Sans-serif
+    .accesskey = a
+
+fonts-monospace = Monospace
+    .accesskey = o
+
+fonts-monospace-size = Maint
+    .accesskey = a
+
+fonts-minsize = Lleiafswm maint ffont
+    .accesskey = L
+
+fonts-minsize-none =
+    .label = Dim
+
+fonts-allow-own =
+    .label = Caniatáu i dudalennau ddewis eu ffont eu hun, yn lle fy newis i uchod
+    .accesskey = C
+
+## Text Encodings
+##
+## Translate the encoding names as adjectives for an encoding, not as the name
+## of the language.
+
+# Variables:
+#   $name {string, "Arial"} - Name of the default font
+fonts-label-default =
+    .label = Rhagosodiad ({ $name })
+fonts-label-default-unnamed =
+    .label = Rhagosodiad
diff --git a/l10n-cy/browser/browser/preferences/formAutofill.ftl b/l10n-cy/browser/browser/preferences/formAutofill.ftl
new file mode 100644
index 0000000000..9627df8d1d
--- /dev/null
+++ b/l10n-cy/browser/browser/preferences/formAutofill.ftl
@@ -0,0 +1,124 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+## The address and credit card autofill management dialog in browser preferences
+
+autofill-manage-addresses-title = Cyfeiriadau wedi eu Cadw
+autofill-manage-addresses-list-header = Cyfeiriadau
+
+autofill-manage-credit-cards-title = Cardiau Credyd wedi eu Cadw
+autofill-manage-credit-cards-list-header = Cardiau Credyd
+
+autofill-manage-dialog =
+    .style = min-width: 560px
+autofill-manage-remove-button = Tynnu
+autofill-manage-add-button = Ychwanegu…
+autofill-manage-edit-button = Golygu…
+
+##
+
+# The dialog title for creating addresses in browser preferences.
+autofill-add-new-address-title = Ychwanegu Cyfeiriad Newydd
+# The dialog title for editing addresses in browser preferences.
+autofill-edit-address-title = Golygu Cyfeiriad
+
+autofill-address-given-name = Enw Cyntaf
+autofill-address-additional-name = Enw Canol
+autofill-address-family-name = Enw Olaf
+autofill-address-organization = Corff
+autofill-address-street = Cyfeiriad Stryd
+
+## address-level-3 (Sublocality) names
+
+# Used in IR, MX
+autofill-address-neighborhood = Cymdogaeth
+# Used in MY
+autofill-address-village-township = Pentref eu Dref
+autofill-address-island = Ynys
+# Used in IE
+autofill-address-townland = Tref
+
+## address-level-2 names
+
+autofill-address-city = Tref/Dinas
+# Used in HK, SD, SY, TR as Address Level-2 and used in KR as Sublocality.
+autofill-address-district = Ardal
+# Used in GB, NO, SE
+autofill-address-post-town = Tref post
+# Used in AU as Address Level-2 and used in ZZ as Sublocality.
+autofill-address-suburb = Maestref
+
+## address-level-1 names
+
+autofill-address-province = Ardal/Talaith
+autofill-address-state = Sir
+autofill-address-county = Sir
+# Used in BB, JM
+autofill-address-parish = Plwyf
+# Used in JP
+autofill-address-prefecture = Rhaglawiaeth
+# Used in HK
+autofill-address-area = Ardal
+# Used in KR
+autofill-address-do-si = Do/Si
+# Used in NI, CO
+autofill-address-department = Adran
+# Used in AE
+autofill-address-emirate = Emirad
+# Used in RU and UA
+autofill-address-oblast = Oblast
+
+## Postal code name types
+
+# Used in IN
+autofill-address-pin = Pin
+autofill-address-postal-code = Cod Post
+autofill-address-zip = Cod Zip
+# Used in IE
+autofill-address-eircode = Eircode
+
+##
+
+autofill-address-country = Gwlad neu Ranbarth
+autofill-address-tel = Ffôn
+autofill-address-email = E-bost
+
+autofill-cancel-button = Diddymu
+autofill-save-button = Cadw
+autofill-country-warning-message = Dim ond ar gyfer rhai gwledydd y mae Awtolanw Ffurflenni ar gael ar hyn o bryd.
+
+# The dialog title for creating credit cards in browser preferences.
+autofill-add-new-card-title = Ychwanegu Cerdyn Credyd Newydd
+# The dialog title for editing credit cards in browser preferences.
+autofill-edit-card-title = Golygu Cerdyn Credyd
+
+# In macOS, this string is preceded by the operating system with "Firefox is trying to ",
+# and has a period added to its end. Make sure to test in your locale.
+autofill-edit-card-password-prompt =
+    { PLATFORM() ->
+        [macos] dangos manylion cerdyn credyd
+        [windows] Mae { -brand-short-name } yn ceisio dangos manylion cerdyn credyd. Cadarnhewch fynediad i'r cyfrif Windows hwn isod.
+       *[other] Mae { -brand-short-name } yn ceisio dangos manylion cerdyn credyd.
+    }
+
+autofill-card-number = Rhif y Cerdyn
+autofill-card-invalid-number = Rhowch rif cerdyn dilys
+autofill-card-name-on-card = Enw ar y Cerdyn
+autofill-card-expires-month = Mis Dod i Ben
+autofill-card-expires-year = Blwyddyn Daw i Ben
+autofill-card-billing-address = Cyfeiriad Archebion
+autofill-card-network = Mathau o Gerdyn
+
+## These are brand names and should only be translated when a locale-specific name for that brand is in common use
+
+autofill-card-network-amex = American Express
+autofill-card-network-cartebancaire = Carte Bancaire
+autofill-card-network-diners = Diners Club
+autofill-card-network-discover = Discover
+autofill-card-network-jcb = JCB
+autofill-card-network-mastercard = MasterCard
+autofill-card-network-mir = MIR
+autofill-card-network-unionpay = Union Pay
+autofill-card-network-visa = Visa
diff --git a/l10n-cy/browser/browser/preferences/fxaPairDevice.ftl b/l10n-cy/browser/browser/preferences/fxaPairDevice.ftl
new file mode 100644
index 0000000000..5d01d540a0
--- /dev/null
+++ b/l10n-cy/browser/browser/preferences/fxaPairDevice.ftl
@@ -0,0 +1,22 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+fxa-pair-device-dialog =
+    .title = Cysylltu Dyfais Arall
+    .style = width: 26em; min-height: 35em;
+fxa-qrcode-heading-step1 = 1. Os nad ydych chi wedi gwneud eisoes, gosodwch <a data-l10n-name="connect-another-device"> Firefox ar eich dyfais symudol </a>.
+fxa-qrcode-heading-step2 = 2. Agor Firefox ar eich dyfais symudol.
+fxa-qrcode-heading-step3 = 3. Agorwch y <b>ddewislen</b> (<img data-l10n-name = "ios-menu-icon" /> neu <img data-l10n-name = "android-menu-icon" />), tapio <img data-l10n-name = "settings-icon" /> <b>Gosodiadau</b> a dewis <b>Cychwyn Sync</b>
+fxa-qrcode-heading-step4 = Sganiwch y cod
+fxa-pair-device-dialog-sync =
+    .style = width: 52em;
+fxa-pair-device-dialog-sync2 =
+    .style = min-width: 52em;
+fxa-qrcode-pair-title = Cydweddwch { -brand-product-name } ar eich ffôn neu dabled
+fxa-qrcode-pair-step1 = 1. Agorwch { -brand-product-name } ar eich dyfais symudol.
+fxa-qrcode-pair-step2 = 2. Agorwch y <strong>ddewislen</strong> (<img data-l10n-name="ios-menu-icon"/> ar iOS neu <img data-l10n-name="android-menu-icon"/> ar Android) a thapiwch <strong>Mewngofnodwch i gydweddu</strong>
+fxa-qrcode-pair-step2-signin = 2. Ewch i'r ddewislen (<img data-l10n-name="ios-menu-icon"/> ar iOS neu <img data-l10n-name="android-menu-icon"/>ar Android) a thapio <strong>Cydweddu a chadw data</strong>
+fxa-qrcode-pair-step3 = 3. Tapiwch <strong>Barod i Sganio</strong> a daliwch eich ffôn dros y cod hwn
+fxa-qrcode-error-title = Paru'n aflwyddiannus.
+fxa-qrcode-error-body = Ceisiwch eto
diff --git a/l10n-cy/browser/browser/preferences/languages.ftl b/l10n-cy/browser/browser/preferences/languages.ftl
new file mode 100644
index 0000000000..2d65864e95
--- /dev/null
+++ b/l10n-cy/browser/browser/preferences/languages.ftl
@@ -0,0 +1,81 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+webpage-languages-window =
+    .title = Gosodiadau Iaith Tudalen Gwe
+    .style = width: 40em
+
+webpage-languages-window2 =
+    .title = Gosodiadau Iaith Tudalen Gwe
+    .style = min-width: 40em
+
+languages-close-key =
+    .key = w
+
+languages-description = Mae tudalennau gwe weithiau'n cael eu cynnig mewn mwy nag un iaith. Dewiswch ieithoedd i'w harddangos, yn nhrefn dewis
+
+languages-customize-spoof-english =
+    .label = Gofyn am fersiwn Saesneg o dudalennau gwe yn y gobaith o well preifatrwydd
+
+languages-customize-moveup =
+    .label = Symud i Fyny
+    .accesskey = F
+
+languages-customize-movedown =
+    .label = Symud i Lawr
+    .accesskey = L
+
+languages-customize-remove =
+    .label = Tynnu
+    .accesskey = T
+
+languages-customize-select-language =
+    .placeholder = Dewis iaith i'w hychwanegu…
+
+languages-customize-add =
+    .label = Ychwanegu
+    .accesskey = Y
+
+# The pattern used to generate strings presented to the user in the
+# locale selection list.
+#
+# Example:
+#   Icelandic [is]
+#   Spanish (Chile) [es-CL]
+#
+# Variables:
+#   $locale (String) - A name of the locale (for example: "Icelandic", "Spanish (Chile)")
+#   $code (String) - Locale code of the locale (for example: "is", "es-CL")
+languages-code-format =
+    .label = { $locale }  [{ $code }]
+
+languages-active-code-format =
+    .value = { languages-code-format.label }
+
+browser-languages-window =
+    .title = { -brand-short-name } Gosodiadau Iaith
+    .style = width: 40em
+
+browser-languages-window2 =
+    .title = { -brand-short-name } Gosodiadau Iaith
+    .style = min-width: 40em
+
+browser-languages-description = Bydd { -brand-short-name } yn dangos yr iaith gyntaf fel eich rhagosodedig a bydd yn danogs ieithoedd eraill yn y drefn fyddan nhw'n ymddangos.
+
+browser-languages-search = Chwilio am ragor o ieithoedd…
+
+browser-languages-searching =
+    .label = Chwilio am ieithoedd…
+
+browser-languages-downloading =
+    .label = Llwytho i lawr…
+
+browser-languages-select-language =
+    .label = Dewis iaith i'w gosod…
+    .placeholder = Dewis iaith i'w gosod…
+
+browser-languages-installed-label = Ieithoedd wedi eu gosod
+browser-languages-available-label = Ieithoedd ar gael
+
+browser-languages-error = Nid yw { -brand-short-name } yn gallu diweddaru eich iaith ar hyn o bryd. Gwiriwch eich bod wedi eich cysylltu i'r rhyngrwyd neu ceisiwch eto.
diff --git a/l10n-cy/browser/browser/preferences/moreFromMozilla.ftl b/l10n-cy/browser/browser/preferences/moreFromMozilla.ftl
new file mode 100644
index 0000000000..abcabe1567
--- /dev/null
+++ b/l10n-cy/browser/browser/preferences/moreFromMozilla.ftl
@@ -0,0 +1,37 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+## These strings are used in the about:preferences moreFromMozilla page
+
+more-from-moz-title = Rhagor gan { -vendor-short-name }
+more-from-moz-category =
+    .tooltiptext = Rhagor gan { -vendor-short-name }
+more-from-moz-subtitle = Edrychwch ar gynnyrch eraill { -vendor-short-name } sy'n gweithio i gefnogi rhyngrwyd iach.
+more-from-moz-firefox-mobile-title = { -brand-product-name } Symudol
+more-from-moz-firefox-mobile-description = Y porwr symudol sy'n rhoi eich preifatrwydd yn gyntaf.
+more-from-moz-firefox-mobile-description-advanced = O rwystro tracwyr i arafu aflonyddwch awtochwarae, mae porwyr symudol { -brand-product-name } yn gweithio goramser i wneud yn siŵr eich bod chi'n cael y rhyngrwyd da.
+more-from-moz-mozilla-vpn-title = { -mozilla-vpn-brand-name }
+more-from-moz-mozilla-vpn-description = Darganfyddwch haen ychwanegol o bori ac diogelwch dienw.
+more-from-moz-mozilla-vpn-description-advanced = Mae { -mozilla-vpn-brand-name } yn ychwanegu haen arall o bori a diogelwch dienw. Ac, yn wahanol i rai VPNau eraill, mae'n ddiogel ac nid yw'n tracio eich gweithgaredd.
+# This string is specific to the product Mozilla Rally which is US only.
+more-from-moz-mozilla-rally-title = { -rally-brand-name }
+# This string is specific to the product Mozilla Rally which is US only.
+more-from-moz-mozilla-rally-description = Rhowch eich data ar waith i gael rhyngrwyd gwell i bawb.
+# This string is specific to the product Mozilla Rally which is US only.
+more-from-moz-mozilla-rally-description-advanced = Cyfrannwch eich data i astudiaethau ymchwil sy'n gweithio i greu rhyngrwyd mwy diogel, mwy agored sy'n helpu pobl ac nid Big Tech.
+# This string is specific to the product Mozilla Rally which is US only.
+more-from-moz-button-mozilla-rally-2 = Ymunwch â { -rally-short-name }
+more-from-moz-qr-code-box-firefox-mobile-title = Llwythwch i lawr gan ddefnyddio'ch dyfais symudol. Pwyntiwch eich camera at y cod QR. Pan fydd dolen yn ymddangos, tapiwch ef.
+more-from-moz-qr-code-box-firefox-mobile-button = Anfon e-bost at eich ffôn yn lle hynny
+more-from-moz-qr-code-firefox-mobile-img =
+    .alt = Y cod QR i'w lwytho { -brand-product-name } Symudol i lawr
+more-from-moz-button-mozilla-vpn-2 = Cael VPN
+more-from-moz-learn-more-link = Dysgu rhagor
+
+## These strings are for the Firefox Relay card in about:preferences moreFromMozilla page
+
+more-from-moz-firefox-relay-title = { -relay-brand-name }
+more-from-moz-firefox-relay-description = Diogelwch eich blwch derbyn a'ch hunaniaeth gydag arallenwau e-bost am ddim.
+more-from-moz-firefox-relay-button = Cael { -relay-brand-short-name }
diff --git a/l10n-cy/browser/browser/preferences/permissions.ftl b/l10n-cy/browser/browser/preferences/permissions.ftl
new file mode 100644
index 0000000000..986778e4f1
--- /dev/null
+++ b/l10n-cy/browser/browser/preferences/permissions.ftl
@@ -0,0 +1,211 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+permissions-window =
+    .title = Eithriadau
+    .style = width: 45em
+permissions-window2 =
+    .title = Eithriadau
+    .style = min-width: 45em
+permissions-close-key =
+    .key = w
+permissions-address = Cyfeiriad y wefan
+    .accesskey = y
+permissions-block =
+    .label = Rhwystro
+    .accesskey = R
+permissions-disable-etp =
+    .label = Ychwanegu Eithriad
+    .accesskey = E
+permissions-session =
+    .label = Caniatáu ar gyfer y Sesiwn
+    .accesskey = S
+permissions-allow =
+    .label = Caniatáu
+    .accesskey = a
+permissions-button-off =
+    .label = Diffodd
+    .accesskey = D
+permissions-button-off-temporarily =
+    .label = Diffodd Dros Dro
+    .accesskey = D
+permissions-site-name =
+    .label = Gwefan
+permissions-status =
+    .label = Statws
+permissions-remove =
+    .label = Tynnu Gwefan
+    .accesskey = T
+permissions-remove-all =
+    .label = Tynnu Pob Gwefan
+    .accesskey = G
+permission-dialog =
+    .buttonlabelaccept = Cadw Newidiadau
+    .buttonaccesskeyaccept = N
+permissions-autoplay-menu = Y rhagosodedig am bob gwefan:
+permissions-searchbox =
+    .placeholder = Chwilio'r Wefan
+permissions-capabilities-autoplay-allow =
+    .label = Caniatáu Sain a Fideo
+permissions-capabilities-autoplay-block =
+    .label = Rhwystro Sain
+permissions-capabilities-autoplay-blockall =
+    .label = Rhwystro Sain a Fideo
+permissions-capabilities-allow =
+    .label = Caniatáu
+permissions-capabilities-block =
+    .label = Rhwystro
+permissions-capabilities-prompt =
+    .label = Gofyn bob Tro
+permissions-capabilities-listitem-allow =
+    .value = Caniatáu
+permissions-capabilities-listitem-block =
+    .value = Rhwystro
+permissions-capabilities-listitem-allow-session =
+    .value = Caniatáu ar gyfer y Sesiwn
+permissions-capabilities-listitem-off =
+    .value = Diffodd
+permissions-capabilities-listitem-off-temporarily =
+    .value = Diffodd dros dro
+
+## Invalid Hostname Dialog
+
+permissions-invalid-uri-title = Rhoddwyd Enw Parth Annilys
+permissions-invalid-uri-label = Rhoi cyfeiriad e-bost dilys
+
+## Exceptions - Tracking Protection
+
+permissions-exceptions-etp-window =
+    .title = Eithriadau ar gyfer Diogelwch Uwch Rhag Tracio
+    .style = { permissions-window.style }
+permissions-exceptions-etp-window2 =
+    .title = Eithriadau ar gyfer Diogelwch Uwch Rhag Tracio
+    .style = { permissions-window2.style }
+permissions-exceptions-etp-desc = Rydych wedi diffodd y diogelu ar y gwefannau hyn.
+permissions-exceptions-manage-etp-desc = Gallwch nodi pa wefannau sydd â Diogelwch Uwch Rhg Tracio wedi'i ddiffodd. Teipiwch union gyfeiriad y wefan rydych chi am ei rheoli ac yna cliciwch ar Ychwanegu Eithriad.
+
+## Exceptions - Cookies
+
+permissions-exceptions-cookie-window =
+    .title = Eithriadau - Cwcis a Data Gwefan
+    .style = { permissions-window.style }
+permissions-exceptions-cookie-window2 =
+    .title = Eithriadau - Cwcis a Data Gwefan
+    .style = { permissions-window2.style }
+permissions-exceptions-cookie-desc = Gallwch bennu pa wefannau sy'n cael defnyddio cwcis a data gwefannau, neu beidio.  Teipiwch union gyfeiriad y wefan rydych am ei reoli ac yna clicio Rhwystro, Caniatáu am y Sesiwn neu Caniatáu.
+
+## Exceptions - HTTPS-Only Mode
+
+permissions-exceptions-https-only-window =
+    .title = Eithriadau - Modd HTTPS-yn-Unig
+    .style = { permissions-window.style }
+permissions-exceptions-https-only-window2 =
+    .title = Eithriadau - Modd HTTPS-yn-Unig
+    .style = { permissions-window2.style }
+permissions-exceptions-https-only-desc = Gallwch ddiffodd Modd HTTPS-yn-Unig ar gyfer gwefannau penodol. Ni fydd { -brand-short-name } yn ceisio uwchraddio'r cysylltiad i sicrhau HTTPS ar gyfer y gwefannau hynny. Nid oes eithriadau ar gyfer ffenestri preifat.
+
+## Exceptions - Pop-ups
+
+permissions-exceptions-popup-window =
+    .title = Gwefannau Caniatawyd - Llamlenni
+    .style = { permissions-window.style }
+permissions-exceptions-popup-window2 =
+    .title = Gwefannau Caniatawyd - Llamlenni
+    .style = { permissions-window2.style }
+permissions-exceptions-popup-desc = Mae modd pennu pa wefannau sy'n cael agor ffenestri llamlen. Teipiwch union gyfeiriad y wefan rydych am ei ganiatáu ac yna clicio Caniatáu.
+
+## Exceptions - Saved Logins
+
+permissions-exceptions-saved-logins-window =
+    .title = Eithriadau - Mewngofnodion wedi eu Cadw
+    .style = { permissions-window.style }
+permissions-exceptions-saved-logins-window2 =
+    .title = Eithriadau - Mewngofnodion wedi eu Cadw
+    .style = { permissions-window2.style }
+permissions-exceptions-saved-logins-desc = Ni fydd mewngofnodion i'r gwefannau canlynol yn cael eu cadw
+
+## Exceptions - Add-ons
+
+permissions-exceptions-addons-window =
+    .title = Gwefannau Caniatawyd - Gosod Ychwanegion
+    .style = { permissions-window.style }
+permissions-exceptions-addons-window2 =
+    .title = Gwefannau Caniatawyd - Gosod Ychwanegion
+    .style = { permissions-window2.style }
+permissions-exceptions-addons-desc = Gallwch enwi pa wefannau sy'n cael gosod ychwanegion. Teipiwch yr union gyfeiriad gwe rydych am ei chaniatáu ac yna clicio Caniatáu.
+
+## Site Permissions - Autoplay
+
+permissions-site-autoplay-window =
+    .title = Gosodiadau - Autochwarae
+    .style = { permissions-window.style }
+permissions-site-autoplay-window2 =
+    .title = Gosodiadau - Autochwarae
+    .style = { permissions-window2.style }
+permissions-site-autoplay-desc = Gallwch reoli'r gwefannau nad ydynt yn eu dilyn eich gosodiadau awtochwarae rhagosodedig yma.
+
+## Site Permissions - Notifications
+
+permissions-site-notification-window =
+    .title = Gosodiadau - Caniatáu Hysbysiadau
+    .style = { permissions-window.style }
+permissions-site-notification-window2 =
+    .title = Gosodiadau - Caniatáu Hysbysiadau
+    .style = { permissions-window2.style }
+permissions-site-notification-desc = Mae'r gwefannau canlynol wedi gofyn i gael anfon hysbysiadau atoch. Gallwch bennu pa wefannau sy'n cael anfon hysbysiadau atoch. Gallwch hefyd rwystro ceisiadau newydd sy'n gofyn i ganiatáu hysbysiadau.
+permissions-site-notification-disable-label =
+    .label = Rhwystro ceisiadau newydd i ganiatáu hysbysiadau
+permissions-site-notification-disable-desc = Bydd hyn yn rhwystro unrhyw wefan sydd heb ei rhestru uchod rhag gofyn am ganiatâd i anfon hysbysiadau. Gall rhwystro hysbysiadau dorri nodweddion rhai gwefannau.
+
+## Site Permissions - Location
+
+permissions-site-location-window =
+    .title = Gosodiadau - Caniatáu Hysbysiadau
+    .style = { permissions-window.style }
+permissions-site-location-window2 =
+    .title = Gosodiadau - Caniatáu Hysbysiadau
+    .style = { permissions-window2.style }
+permissions-site-location-desc = Mae'r gwefannau canlynol wedi gofyn i gael mynediad at eich lleoliad. Gallwch bennu pa wefannau sy'n cael mynediad at eich lleoliad. Gallwch hefyd rwystro ceisiadau newydd sy'n gofyn i gael mynediad at eich lleoliad.
+permissions-site-location-disable-label =
+    .label = Rhwystro ceisiadau newydd sy'n gofyn i gael mynediad at eich lleoliad
+permissions-site-location-disable-desc = Bydd hyn yn rhwystro unrhyw wefan sydd heb ei rhestru uchod rhag gofyn am ganiatâd i gael mynediad at eich lleoliad. Gall rhwystro mynediad at eich lleoliad dorri nodweddion rhai gwefannau.
+
+## Site Permissions - Virtual Reality
+
+permissions-site-xr-window =
+    .title = Gosodiadau - Caniatâd Rhithrealaeth
+    .style = { permissions-window.style }
+permissions-site-xr-window2 =
+    .title = Gosodiadau - Caniatâd Rhithrealaeth
+    .style = { permissions-window2.style }
+permissions-site-xr-desc = Mae'r gwefannau canlynol wedi gofyn am gael mynediad at eich dyfeisiau rhithrealaeth. Gallwch chi nodi pa wefannau sy'n cael mynediad at eich dyfeisiau rhithrealaeth. Gallwch hefyd rwystro ceisiadau newydd sy'n gofyn am gael mynediad at eich dyfeisiau rhithrealaeth .
+permissions-site-xr-disable-label =
+    .label = Rhwystro geisiadau newydd sy'n gofyn am gael mynediad at eich dyfeisiau rhithrealaeth
+permissions-site-xr-disable-desc = Bydd hyn yn rhwystro unrhyw wefan sydd heb ei rhestru uchod rhag gofyn am ganiatâd i gael mynediad at eich dyfeisiau rhithrealaeth. Gall rhwystro mynediad at eich dyfeisiau rhithrealaeth dorri nodweddion rhai gwefannau.
+
+## Site Permissions - Camera
+
+permissions-site-camera-window =
+    .title = Gosodiadau - Caniatâd Camera
+    .style = { permissions-window.style }
+permissions-site-camera-window2 =
+    .title = Gosodiadau - Caniatâd Camera
+    .style = { permissions-window2.style }
+permissions-site-camera-desc = Mae'r gwefannau canlynol wedi gofyn i gael mynediad i'ch camera. Gallwch bennu pa wefannau sy'n cael mynediad at eich camera. Gallwch hefyd rwystro ceisiadau newydd sy'n gofyn i gael mynediad at eich camera.
+permissions-site-camera-disable-label =
+    .label = Rhwystro ceisiadau newydd sy'n gofyn i gael mynediad at eich camera
+permissions-site-camera-disable-desc = Bydd hyn yn rhwystro unrhyw wefan sydd heb ei rhestru uchod rhag gofyn am ganiatâd i gael mynediad at eich camera. Gall rhwystro mynediad at eich camera dorri nodweddion rhai gwefannau.
+
+## Site Permissions - Microphone
+
+permissions-site-microphone-window =
+    .title = Gosodiadau - Caniatâd Meicroffon
+    .style = { permissions-window.style }
+permissions-site-microphone-window2 =
+    .title = Gosodiadau - Caniatâd Meicroffon
+    .style = { permissions-window2.style }
+permissions-site-microphone-desc = Mae'r gwefannau canlynol wedi gofyn i gael mynediad at eich meicroffon. Gallwch bennu pa wefannau sy'n cael mynediad at eich meicroffon. Gallwch hefyd rwystro ceisiadau newydd sy'n gofyn i gael mynediad at eich meicroffon.
+permissions-site-microphone-disable-label =
+    .label = Rhwystro ceisiadau newydd sy'n gofyn i gael mynediad at eich meicroffon
+permissions-site-microphone-disable-desc = Bydd hyn yn rhwystro unrhyw wefan sydd heb ei rhestru uchod rhag gofyn am ganiatâd i gael mynediad at eich meicroffon. Gall rhwystro mynediad at eich meicroffon dorri nodweddion rhai gwefannau.
diff --git a/l10n-cy/browser/browser/preferences/preferences.ftl b/l10n-cy/browser/browser/preferences/preferences.ftl
new file mode 100644
index 0000000000..a6656e5e91
--- /dev/null
+++ b/l10n-cy/browser/browser/preferences/preferences.ftl
@@ -0,0 +1,1199 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+do-not-track-description = Anfon neges “Dim Tracio” at wefannau nad ydych am gael eich tracio
+do-not-track-learn-more = Dysgu rhagor
+do-not-track-option-default-content-blocking-known =
+    .label = Dim ond pan mae { -brand-short-name } wedi ei osod i rwystro tracwyr hysbys.
+do-not-track-option-always =
+    .label = Bob tro
+settings-page-title = Gosodiadau
+# This is used to determine the width of the search field in about:preferences,
+# in order to make the entire placeholder string visible
+#
+# Please keep the placeholder string short to avoid truncation.
+#
+# Notice: The value of the `.style` attribute is a CSS string, and the `width`
+# is the name of the CSS property. It is intended only to adjust the element's width.
+# Do not translate.
+search-input-box2 =
+    .style = width: 15.4em
+    .placeholder = Canfod yn y Gosodiadau
+managed-notice = Mae eich porwr yn cael ei reoli gan eich sefydliad.
+category-list =
+    .aria-label = Categorïau
+pane-general-title = Cyffredinol
+category-general =
+    .tooltiptext = { pane-general-title }
+pane-home-title = Cartref
+category-home =
+    .tooltiptext = { pane-home-title }
+pane-search-title = Chwilio
+category-search =
+    .tooltiptext = { pane-search-title }
+pane-privacy-title = Preifatrwydd a Diogelwch
+category-privacy =
+    .tooltiptext = { pane-privacy-title }
+pane-sync-title3 = Sync
+category-sync3 =
+    .tooltiptext = { pane-sync-title3 }
+pane-experimental-title = Arbrofion { -brand-short-name }
+category-experimental =
+    .tooltiptext = Arbrofion { -brand-short-name }
+pane-experimental-subtitle = Gofal!
+pane-experimental-search-results-header = Arbrofion { -brand-short-name }: Byddwch yn Ofalus
+pane-experimental-description2 = Gall newid dewisiadau ffurfweddiad uwch effeithio ar berfformiad neu ddiogelwch { -brand-short-name }.
+pane-experimental-reset =
+    .label = Adfer y Rhagosodiadau
+    .accesskey = A
+help-button-label = Cefnogaeth { -brand-short-name }
+addons-button-label = Estyniadau a Themâu
+focus-search =
+    .key = f
+close-button =
+    .aria-label = Cau
+
+## Browser Restart Dialog
+
+feature-enable-requires-restart = Rhaid ailgychwyn { -brand-short-name } i alluogi'r nodwedd hon.
+feature-disable-requires-restart = Rhaid ailgychwyn { -brand-short-name } i analluogi'r nodwedd hon.
+should-restart-title = Ailgychwyn { -brand-short-name }
+should-restart-ok = Ailgychwynnwch { -brand-short-name } nawr
+cancel-no-restart-button = Diddymu
+restart-later = Ailgychwyn Rhywbryd Eto
+
+## Extension Control Notifications
+##
+## These strings are used to inform the user
+## about changes made by extensions to browser settings.
+##
+## <img data-l10n-name="icon"/> is going to be replaced by the extension icon.
+##
+## Variables:
+##   $name (String): name of the extension
+
+# This string is shown to notify the user that the password manager setting
+# is being controlled by an extension
+extension-controlling-password-saving = <img data-l10n-name="icon"/> <strong>{ $name }</strong> sy'n rheoli'r gosodiad hwn.
+# This string is shown to notify the user that their notifications permission
+# is being controlled by an extension.
+extension-controlling-web-notifications = <img data-l10n-name="icon"/> <strong>{ $name }</strong> sy'n rheoli'r gosodiad hwn.
+# This string is shown to notify the user that Container Tabs
+# are being enabled by an extension.
+extension-controlling-privacy-containers = Mae <img data-l10n-name="icon"/> <strong>{ $name }</strong> angen Tabiau Cynhwysydd.
+# This string is shown to notify the user that their content blocking "All Detected Trackers"
+# preferences are being controlled by an extension.
+extension-controlling-websites-content-blocking-all-trackers = <img data-l10n-name="icon"/> <strong>{ $name }</strong> sy'n rheoli'r gosodiad hwn.
+# This string is shown to notify the user that their proxy configuration preferences
+# are being controlled by an extension.
+extension-controlling-proxy-config = Mae estyniad <img data-l10n-name="icon"/> <strong>{ $name }</strong>, yn rheoli sut mae { -brand-short-name } yn cysylltu â'r rhyngrwyd.
+# This string is shown after the user disables an extension to notify the user
+# how to enable an extension that they disabled.
+#
+# <img data-l10n-name="addons-icon"/> will be replaced with Add-ons icon
+# <img data-l10n-name="menu-icon"/> will be replaced with Menu icon
+extension-controlled-enable = I alluogi'r estyniad ewch i Ychwanegion <img data-l10n-name="addons-icon"/> yn y ddewislen <img data-l10n-name="menu-icon"/>.
+
+## Preferences UI Search Results
+
+search-results-header = Canlyniadau Chwilio
+# `<span data-l10n-name="query"></span>` will be replaced by the search term.
+search-results-empty-message2 = Ymddiheuriadau! Nid oes canlyniadau yn y Dewisiadau ar gyfer “<span data-l10n-name="query"></span>”.
+search-results-help-link = Angen help? Ewch i <a data-l10n-name="url">Cefnogaeth { -brand-short-name }</a>
+
+## General Section
+
+startup-header = Cychwyn
+always-check-default =
+    .label = Wrth gychwyn, gwirio ai { -brand-short-name } yw eich porwr ragosodedig
+    .accesskey = W
+is-default = { -brand-short-name } yw eich porwr rhagosodedig cyfredol
+is-not-default = { -brand-short-name } yw eich porwr rhagosodedig cyfredol
+set-as-my-default-browser =
+    .label = Gwneud yn Ragosodedig…
+    .accesskey = R
+startup-restore-windows-and-tabs =
+    .label = Agor ffenestri a thabiau blaenorol
+    .accesskey = A
+startup-restore-warn-on-quit =
+    .label = Rhybuddio wrth adael y porwr
+disable-extension =
+    .label = Analluogi Estyniad
+tabs-group-header = Tabiau
+ctrl-tab-recently-used-order =
+    .label = Mae Ctrl+Tab yn cylchdroi drwy dabiau yn y drefn y'u defnyddiwyd yn ddiweddar
+    .accesskey = T
+open-new-link-as-tabs =
+    .label = Agor dolenni mewn tabiau ac nid mewn ffenestri newydd
+    .accesskey = f
+confirm-on-close-multiple-tabs =
+    .label = Cadarnhau cyn cau tabiau lluosog
+    .accesskey = l
+# This string is used for the confirm before quitting preference.
+# Variables:
+#   $quitKey (String) - the quit keyboard shortcut, and formatted
+#                       in the same manner as it would appear,
+#                       for example, in the File menu.
+confirm-on-quit-with-key =
+    .label = Cadarnhau cyn gadael gyda { $quitKey }
+    .accesskey = g
+warn-on-open-many-tabs =
+    .label = Rhybuddio y gall agor mwy nag un tab arafu { -brand-short-name }
+    .accesskey = a
+switch-to-new-tabs =
+    .label = Wrth agor dolen, delwedd neu gyfrwng mewn tab newydd, symud yn syth iddo
+    .accesskey = s
+show-tabs-in-taskbar =
+    .label = Dangos rhagolwg tab ym mar tasgau Windows
+    .accesskey = D
+browser-containers-enabled =
+    .label = Galluogi Tabiau Cynwysyddion
+    .accesskey = G
+browser-containers-learn-more = Dysgu rhagor
+browser-containers-settings =
+    .label = Gosodiadau…
+    .accesskey = G
+containers-disable-alert-title = Cau Tabiau Pob Cynhwysydd?
+containers-disable-alert-desc =
+    { $tabCount ->
+        [zero] Os fyddwch yn analluogi'r Tabiau Cynhwysydd, nid fydd tabiau cynhwysydd yn cael eu cau. Ydych chi'n siŵr eich bod am analluogi Tabiau Cynhwysyddion?
+        [one] Os fyddwch yn analluogi Tabiau Cynwysyddion nawr, bydd { $tabCount } cynhwysydd tabiau yn cael ei gau. Ydych chi'n siŵr eich bod am analluogi Tabiau Cynhwysyddion?
+        [two] Os fyddwch yn analluogi Tabiau Cynwysyddion nawr, bydd { $tabCount } gynhwysydd tabiau yn cael eu cau. Ydych chi'n siŵr eich bod am analluogi Tabiau Cynhwysyddion?
+        [few] Os fyddwch yn analluogi Tabiau Cynwysyddion nawr, bydd { $tabCount } chynhwysydd tabiau yn cael eu cau. Ydych chi'n siŵr eich bod am analluogi Tabiau Cynhwysyddion?
+        [many] Os fyddwch yn analluogi Tabiau Cynwysyddion nawr, bydd { $tabCount } cynhwysydd tabiau yn cael eu cau. Ydych chi'n siŵr eich bod am analluogi Tabiau Cynhwysyddion?
+       *[other] Os fyddwch yn analluogi Tabiau Cynwysyddion nawr, bydd { $tabCount } cynhwysydd tabiau yn cael eu cau. Ydych chi'n siŵr eich bod am analluogi Tabiau Cynhwysyddion?
+    }
+containers-disable-alert-ok-button =
+    { $tabCount ->
+        [zero] Peidio Cau Tabiau Cynhwysydd
+        [one] Cau { $tabCount } Tab Cynhwysydd
+        [two] Cau { $tabCount } Dab Cynhwysydd
+        [few] Cau { $tabCount } Thab Cynhwysydd
+        [many] Cau { $tabCount } Thab Cynhwysydd
+       *[other] Cau { $tabCount } Tab Cynhwysydd
+    }
+containers-disable-alert-cancel-button = Cadw wedi ei alluogi
+containers-remove-alert-title = Tynnu'r Cynhwysydd Hwn?
+# Variables:
+#   $count (Number) - Number of tabs that will be closed.
+containers-remove-alert-msg =
+    { $count ->
+        [zero] Os fyddwch yn tynnu'r cynhwysydd hwn nawr, ni fydd tabiau yn cael eu cau. Ydych chi'n siŵr eich bod am dynnu'r Cynhwysydd hwn?
+        [one] Os fyddwch yn tynnu'r cynhwysydd hwn nawr, bydd { $count } tab yn cael ei gau. Ydych chi'n siŵr eich bod am dynnu'r Cynhwysydd hwn?
+        [two] Os fyddwch yn tynnu'r cynhwysydd hwn nawr, bydd { $count } dab yn cael eu cau. Ydych chi'n siŵr eich bod am dynnu'r Cynhwysydd hwn?
+        [few] Os fyddwch yn tynnu'r cynhwysydd hwn nawr, bydd { $count } thab yn cael eu cau. Ydych chi'n siŵr eich bod am dynnu'r Cynhwysydd hwn?
+        [many] Os fyddwch yn tynnu'r cynhwysydd hwn nawr, bydd { $count } thab yn cael eu cau. Ydych chi'n siŵr eich bod am dynnu'r Cynhwysydd hwn?
+       *[other] Os fyddwch yn tynnu'r cynhwysydd hwn nawr, bydd { $count } tab yn cael eu cau. Ydych chi'n siŵr eich bod am dynnu'r Cynhwysydd hwn?
+    }
+containers-remove-ok-button = Tynnu'r Cynhwysydd Hwn
+containers-remove-cancel-button = Peidio Tynnu'r Cynhwysydd Hwn
+
+## General Section - Language & Appearance
+
+language-and-appearance-header = Iaith a Gwedd
+preferences-web-appearance-header = Gwedd gwefan
+preferences-web-appearance-description = Mae rhai gwefannau yn addasu eu cynllun lliw yn seiliedig ar eich dewisiadau. Dewiswch pa gynllun lliw yr hoffech ei ddefnyddio ar gyfer y gwefannau hynny.
+preferences-web-appearance-choice-browser = Thema { -brand-short-name }
+preferences-web-appearance-choice-system = Thema'r system
+preferences-web-appearance-choice-auto = Awtomatig
+preferences-web-appearance-choice-light = Golau
+preferences-web-appearance-choice-dark = Tywyll
+preferences-web-appearance-choice-tooltip-browser =
+    .title = Cydweddwch eich gosodiadau thema { -brand-short-name } ar gyfer cefndiroedd gwefannau a chynnwys.
+preferences-web-appearance-choice-tooltip-system =
+    .title = Cydweddwch eich gosodiadau system ar gyfer cefndiroedd gwefannau a chynnwys.
+preferences-web-appearance-choice-tooltip-auto =
+    .title = Newidiwch gefndir a chynnwys gwefan yn awtomatig yn seiliedig ar osodiadau eich system a thema { -brand-short-name }.
+preferences-web-appearance-choice-tooltip-light =
+    .title = Defnyddio gwedd olau ar gyfer cefndiroedd gwefannau a chynnwys.
+preferences-web-appearance-choice-tooltip-dark =
+    .title = Defnyddio gwedd dywyll ar gyfer cefndiroedd gwefan a chynnwys.
+preferences-web-appearance-choice-input-browser =
+    .aria-description = { preferences-web-appearance-choice-tooltip-browser.title }
+preferences-web-appearance-choice-input-system =
+    .aria-description = { preferences-web-appearance-choice-tooltip-system.title }
+preferences-web-appearance-choice-input-auto =
+    .aria-description = { preferences-web-appearance-choice-tooltip-auto.title }
+preferences-web-appearance-choice-input-light =
+    .aria-description = { preferences-web-appearance-choice-tooltip-light.title }
+preferences-web-appearance-choice-input-dark =
+    .aria-description = { preferences-web-appearance-choice-tooltip-dark.title }
+# This can appear when using windows HCM or "Override colors: always" without
+# system colors.
+preferences-web-appearance-override-warning = Mae eich dewisiadau lliw yn drech nag gwedd gwefan. <a data-l10n-name="colors-link">Rheoli lliwiau</a>
+# This message contains one link. It can be moved within the sentence as needed
+# to adapt to your language, but should not be changed.
+preferences-web-appearance-footer = Rheoli themâu { -brand-short-name } yn <a data-l10n-name="themes-link">Estyniadau a Themâu</a>
+preferences-colors-header = Lliwiau
+preferences-colors-description = Diystyru lliwiau rhagosodedig { -brand-short-name } mewn perthynas â thestun, cefndiroedd gwefannau a dolenni.
+preferences-colors-manage-button =
+    .label = Rheoli Lliwiau…
+    .accesskey = R
+preferences-fonts-header = Ffontiau
+default-font = Ffont rhagosodedig:
+    .accesskey = F
+default-font-size = Maint:
+    .accesskey = M
+advanced-fonts =
+    .label = Uwch…
+    .accesskey = w
+# Zoom is a noun, and the message is used as header for a group of options
+preferences-zoom-header = Chwyddo
+preferences-default-zoom = Chwyddo rhagosodedig
+    .accesskey = C
+preferences-default-zoom-value =
+    .label = { $percentage }%
+preferences-zoom-text-only =
+    .label = Chwyddo testun yn unig
+    .accesskey = t
+language-header = Iaith
+choose-language-description = Dewiswch eich dewis o iaith i ddangos tudalennau
+choose-button =
+    .label = Dewis…
+    .accesskey = D
+choose-browser-language-description = Dewiswch yr iaith i ddangos dewislenni, negeseuon a hysbysiadau gan { -brand-short-name }
+manage-browser-languages-button =
+    .label = Gosod Rhai Eraill
+    .accesskey = G
+confirm-browser-language-change-description = Ailgychwyn { -brand-short-name } i osod y newidiadau hyn
+confirm-browser-language-change-button = Gosod ac Ailgychwyn
+translate-web-pages =
+    .label = Cyfieithu cynnwys gwe
+    .accesskey = C
+fx-translate-web-pages = { -translations-brand-name }
+# The <img> element is replaced by the logo of the provider
+# used to provide machine translations for web pages.
+translate-attribution = Cyfieithiadau gan <img data-l10n-name="logo"/>
+translate-exceptions =
+    .label = Eithriadau…
+    .accesskey = i
+# Variables:
+#    $localeName (string) - Localized name of the locale to be used.
+use-system-locale =
+    .label = Defnyddiwch osodiadau eich system weithredu ar gyfer “{ $localeName }” i fformatio dyddiadau, amseroedd, rhifau a mesuriadau.
+check-user-spelling =
+    .label = Gwirio'r sillafu wrth deipio
+    .accesskey = G
+
+## General Section - Files and Applications
+
+files-and-applications-title = Ffeiliau a Rhaglenni
+download-header = Llwytho i Lawr
+download-save-where = Cadw ffeiliau yn
+    .accesskey = a
+download-choose-folder =
+    .label =
+        { PLATFORM() ->
+            [macos] Dewis…
+           *[other] Pori…
+        }
+    .accesskey =
+        { PLATFORM() ->
+            [macos] D
+           *[other] P
+        }
+download-always-ask-where =
+    .label = Gofyn i mi lle i gadw ffeiliau
+    .accesskey = G
+applications-header = Rhaglenni
+applications-description = Dewiswch sut mae { -brand-short-name } yn trin y ffeiliau rydych wedi eu llwytho i lawr o'r we neu'r rhaglenni rydych yn eu defnyddio wrth bori.
+applications-filter =
+    .placeholder = Chwilio'r mathau o ffeil neu raglenni
+applications-type-column =
+    .label = Math o Gynnwys
+    .accesskey = M
+applications-action-column =
+    .label = Gweithred
+    .accesskey = G
+# Variables:
+#   $extension (String) - file extension (e.g .TXT)
+applications-file-ending = Ffeil { $extension }
+applications-action-save =
+    .label = Cadw Ffeil
+# Variables:
+#   $app-name (String) - Name of an application (e.g Adobe Acrobat)
+applications-use-app =
+    .label = Defnyddio { $app-name }
+# Variables:
+#   $app-name (String) - Name of an application (e.g Adobe Acrobat)
+applications-use-app-default =
+    .label = Defnyddio { $app-name } (rhagosodiad)
+applications-use-os-default =
+    .label =
+        { PLATFORM() ->
+            [macos] Defnyddiwch raglen ragosodedig macOS
+            [windows] Defnyddiwch raglen ragosodedig Windows
+           *[other] Defnyddiwch raglen ragosodedig y system
+        }
+applications-use-other =
+    .label = Defnyddio arall…
+applications-select-helper = Dewis Rhaglen Gynorthwyol
+applications-manage-app =
+    .label = Manylion y Rhaglen…
+applications-always-ask =
+    .label = Gofyn bob tro
+# Variables:
+#   $type-description (String) - Description of the type (e.g "Portable Document Format")
+#   $type (String) - the MIME type (e.g application/binary)
+applications-type-description-with-type = { $type-description } ({ $type })
+# Variables:
+#   $extension (String) - file extension (e.g .TXT)
+#   $type (String) - the MIME type (e.g application/binary)
+applications-file-ending-with-type = { applications-file-ending } ({ $type })
+# Variables:
+#   $plugin-name (String) - Name of a plugin (e.g Adobe Flash)
+applications-use-plugin-in =
+    .label = Defnyddio { $plugin-name } (yn { -brand-short-name })
+applications-open-inapp =
+    .label = Agorwch yn { -brand-short-name }
+
+## The strings in this group are used to populate
+## selected label element based on the string from
+## the selected menu item.
+
+applications-use-plugin-in-label =
+    .value = { applications-use-plugin-in.label }
+applications-action-save-label =
+    .value = { applications-action-save.label }
+applications-use-app-label =
+    .value = { applications-use-app.label }
+applications-open-inapp-label =
+    .value = { applications-open-inapp.label }
+applications-always-ask-label =
+    .value = { applications-always-ask.label }
+applications-use-app-default-label =
+    .value = { applications-use-app-default.label }
+applications-use-other-label =
+    .value = { applications-use-other.label }
+applications-use-os-default-label =
+    .value = { applications-use-os-default.label }
+
+##
+
+applications-handle-new-file-types-description = Beth ddylai { -brand-short-name } ei wneud gyda ffeiliau eraill?
+applications-save-for-new-types =
+    .label = Cadw ffeiliau
+    .accesskey = C
+applications-ask-before-handling =
+    .label = Gofyn a ydych am agor neu gadw ffeiliau
+    .accesskey = G
+drm-content-header = Cynnwys Rheoli Hawliau Digidol (DRM)
+play-drm-content =
+    .label = Chwarae cynnwys wedi ei reoli gan DRM
+    .accesskey = C
+play-drm-content-learn-more = Dysgu rhagor
+update-application-title = Diweddariadau { -brand-short-name }
+update-application-description = Cadwch { -brand-short-name } yn gyfredol am y perfformiad, y sefydlogrwydd a'r diogelwch gorau.
+update-application-version = Fersiwn { $version } <a data-l10n-name="learn-more">Beth sy'n newydd</a>
+update-history =
+    .label = Dangos Hanes Diweddaru…
+    .accesskey = D
+update-application-allow-description = Caniatáu i { -brand-short-name }
+update-application-auto =
+    .label = Gosod diweddariadau'n awtomatig (argymell)
+    .accesskey = G
+update-application-check-choose =
+    .label = Gwirio am ddiweddariadau, ond gadael i mi ddewis i'w gosod a'i peidio
+    .accesskey = G
+update-application-manual =
+    .label = Byth gwirio am ddiweddariadau (ddim yn argymell)
+    .accesskey = B
+update-application-background-enabled =
+    .label = Pan nad yw { -brand-short-name } yn rhedeg
+    .accesskey = P
+update-application-warning-cross-user-setting = Bydd y gosodiad hwn yn berthnasol i bob cyfrif Windows a proffiliau { -brand-short-name } sy'n ddefnyddio'r gosodiad { -brand-short-name } hwn.
+update-application-use-service =
+    .label = Defnyddio gwasanaethau cefndirol i osod diweddariadau
+    .accesskey = c
+update-application-suppress-prompts =
+    .label = Dangos llai o anogwyr hysbysu diweddariadau
+    .accesskey = D
+update-setting-write-failure-title2 = Gwall wrth gadw dewisiadau Diweddaru
+# Variables:
+#   $path (String) - Path to the configuration file
+# The newlines between the main text and the line containing the path is
+# intentional so the path is easier to identify.
+update-setting-write-failure-message2 =
+    Bu gwall ar { -brand-short-name } ac nid yw wedi cadw'r newid hwn. Sylwch fod gosod caniatâd ar gyfer y diweddariad hwn yn gofyn am ganiatâd i ysgrifennu at y ffeil isod. Efallai y byddwch chi neu weinyddwr system yn gallu datrys y gwall trwy roi rheolaeth lawn i'r ffeil hon i'r grŵp Defnyddwyr.
+    
+    Methu ysgrifennu i ffeil: { $path }
+update-in-progress-title = Wrthi'n Diweddaru
+update-in-progress-message = Hoffech chi i { -brand-short-name } barhau gyda'r diweddariad hwn?
+update-in-progress-ok-button = &Dileu
+# Continue is the cancel button so pressing escape or using a platform standard
+# method of closing the UI will not discard the update.
+update-in-progress-cancel-button = &Parhau
+
+## General Section - Performance
+
+performance-title = Perfformiad
+performance-use-recommended-settings-checkbox =
+    .label = Defnyddio'r gosodiadau perfformiad sy'n cael eu hargymell
+    .accesskey = D
+performance-use-recommended-settings-desc = Mae'r gosodiadau hyn wedi eu teilwrio i galedwedd a system weithredu eich cyfrifiadur.
+performance-settings-learn-more = Dysgu rhagor
+performance-allow-hw-accel =
+    .label = Defnyddio cyflymu caledwedd pan fydd ar gael
+    .accesskey = e
+performance-limit-content-process-option = Terfyn proses cynnwys
+    .accesskey = T
+performance-limit-content-process-enabled-desc = Mae rhagor o brosesau cynnwys yn gallu gwella perfformiad pan yn defnyddio tabiau lluosog, ond fydd hefyd yn defnyddio mwy o gof.
+performance-limit-content-process-blocked-desc = Dim ond yn y fersiwn amlbroses o { -brand-short-name } y mae newid y nifer o brosesau cynnwys yn bosib. <a data-l10n-name="learn-more">Dysgwch sut i weld os yw aml-brosesu wedi ei alluogi</a>
+# Variables:
+#   $num - default value of the `dom.ipc.processCount` pref.
+performance-default-content-process-count =
+    .label = { $num } (rhagosodiad)
+
+## General Section - Browsing
+
+browsing-title = Pori
+browsing-use-autoscroll =
+    .label = Defnyddio awto sgrolio
+    .accesskey = a
+browsing-use-smooth-scrolling =
+    .label = Defnyddio sgrolio llyfn
+    .accesskey = s
+browsing-gtk-use-non-overlay-scrollbars =
+    .label = Dangos bariau sgrolio bob tro
+    .accesskey = D
+browsing-use-onscreen-keyboard =
+    .label = Dangos bysellfwrdd cyffwrdd pan fydd angen
+    .accesskey = b
+browsing-use-cursor-navigation =
+    .label = Defnyddio bysellau'r cyrchwr ar gyfer symud o fewn tudalennau
+    .accesskey = D
+browsing-search-on-start-typing =
+    .label = Chwilio am destun wrth i mi gychwyn teipio
+    .accesskey = d
+browsing-picture-in-picture-toggle-enabled =
+    .label = Galluogi rheolyddion fideo Llun mewn Llun
+    .accesskey = G
+browsing-picture-in-picture-learn-more = Dysgu rhagor
+browsing-media-control =
+    .label = Rheoli cyfryngau trwy fysellfwrdd, penset neu ryngwyneb rhithwir
+    .accesskey = t
+browsing-media-control-learn-more = Dysgu rhagor
+browsing-cfr-recommendations =
+    .label = Argymell estyniadau wrth i chi bori
+    .accesskey = A
+browsing-cfr-features =
+    .label = Argymell nodweddion wrth bori
+    .accesskey = A
+browsing-cfr-recommendations-learn-more = Dysgu Rhagor
+
+## General Section - Proxy
+
+network-settings-title = Gosodiadau Rhwydwaith
+network-proxy-connection-description = Ffurfweddwch sut mae { -brand-short-name } yn cysylltu â'r rhyngrwyd.
+network-proxy-connection-learn-more = Dysgu rhagor
+network-proxy-connection-settings =
+    .label = Gosodiadau…
+    .accesskey = G
+
+## Home Section
+
+home-new-windows-tabs-header = Ffenestri a Thabiau Newydd
+home-new-windows-tabs-description2 = Dewiswch beth fyddwch yn ei weld wrth i chi agor eich tudalen cartref, ffenestri newydd a thabiau newydd.
+
+## Home Section - Home Page Customization
+
+home-homepage-mode-label = Tudalen cartref a ffenestri newydd
+home-newtabs-mode-label = Tabiau newydd
+home-restore-defaults =
+    .label = Adfer gosodiadau
+    .accesskey = A
+# "Firefox" should be treated as a brand and kept in English,
+# while "Home" and "(Default)" can be localized.
+home-mode-choice-default =
+    .label = Cartref Firefox (Rhagosodiad)
+home-mode-choice-default-fx =
+    .label = { -firefox-home-brand-name } (Rhagosodedig)
+home-mode-choice-custom =
+    .label = URLau Cyfaddas...
+home-mode-choice-blank =
+    .label = Tudalen Wag
+home-homepage-custom-url =
+    .placeholder = Gludo URL...
+# This string has a special case for '1' and [other] (default). If necessary for
+# your language, you can add {$tabCount} to your translations and use the
+# standard CLDR forms, or only use the form for [other] if both strings should
+# be identical.
+use-current-pages =
+    .label =
+        { $tabCount ->
+            [1] Defnyddio'r Dudalen Bresennol
+           *[other] Defnyddio'r Dudalen Bresennol
+        }
+    .accesskey = B
+choose-bookmark =
+    .label = Defnyddio Nod Tudalen…
+    .accesskey = N
+
+## Home Section - Firefox Home Content Customization
+
+home-prefs-content-header = Cynnwys Cartref Firefox
+home-prefs-content-description = Dewis pa gynnwys rydych eisiau ar eich sgrin Firefox Cartref.
+home-prefs-content-header2 = Cynnwys { -firefox-home-brand-name }
+home-prefs-content-description2 = Dewiswch pa gynnwys rydych chi ei eisiau ar eich sgrin { -firefox-home-brand-name }.
+home-prefs-search-header =
+    .label = Chwilio'r We
+home-prefs-shortcuts-header =
+    .label = Llwybrau Byr
+home-prefs-shortcuts-description = Gwefannau rydych yn eu cadw neu'n ymweld â nhw
+home-prefs-shortcuts-by-option-sponsored =
+    .label = Llwybrau byr wedi'u noddi
+
+## Variables:
+##  $provider (String): Name of the corresponding content provider, e.g "Pocket".
+
+home-prefs-recommended-by-header =
+    .label = Argymhellwyd gan { $provider }
+home-prefs-recommended-by-description-new = Cynnwys eithriadol wedi'u curadu gan { $provider }, rhan o deulu { -brand-product-name }
+
+##
+
+home-prefs-recommended-by-learn-more = Sut mae'n gweithio
+home-prefs-recommended-by-option-sponsored-stories =
+    .label = Straeon wedi eu Noddi
+home-prefs-recommended-by-option-recent-saves =
+    .label = Dangos Eitemau wedi'u Cadw'n Diweddar
+home-prefs-highlights-option-visited-pages =
+    .label = Tudalennau Ymwelwyd â Nhw
+home-prefs-highlights-options-bookmarks =
+    .label = Nodau Tudalen
+home-prefs-highlights-option-most-recent-download =
+    .label = Llwytho i Lawr Mwyaf Diweddar
+home-prefs-highlights-option-saved-to-pocket =
+    .label = Tudalennau wedi eu Cadw i { -pocket-brand-name }
+home-prefs-recent-activity-header =
+    .label = Gweithgaredd diweddar
+home-prefs-recent-activity-description = Detholiad o wefannau a chynnwys diweddar
+# For the "Snippets" feature traditionally on about:home.
+# Alternative translation options: "Small Note" or something that
+# expresses the idea of "a small message, shortened from something else,
+# and non-essential but also not entirely trivial and useless.
+home-prefs-snippets-header =
+    .label = Pytiau
+home-prefs-snippets-description-new = Awgrymiadau a newyddion gan { -vendor-short-name } a { -brand-product-name }
+home-prefs-sections-rows-option =
+    .label =
+        { $num ->
+            [zero] { $num } rhes
+            [one] { $num } rhes
+            [two] { $num } rhes
+            [few] { $num } rhes
+            [many] { $num } rhes
+           *[other] { $num } rhes
+        }
+
+## Search Section
+
+search-bar-header = Bar Chwilio
+search-bar-hidden =
+    .label = Defnyddio'r bar cyfeiriadau ar gyfer chwilio a llywio
+search-bar-shown =
+    .label = Ychwanegu'r bar chwilio i'r bar offer
+search-engine-default-header = Peiriant Chwilio Rhagosodedig
+search-engine-default-desc-2 = Hwn yw'ch peiriant chwilio rhagosodedig yn y bar cyfeiriad a'r bar chwilio. Gallwch ei newid ar unrhyw adeg.
+search-engine-default-private-desc-2 = Dewiswch beiriant chwilio rhagosodedig i'w ddefnyddio yn y Ffenestr Breifat yn unig.
+search-separate-default-engine =
+    .label = Defnyddio'r peiriant chwilio hwn mewn Ffenestri Preifat
+    .accesskey = D
+search-suggestions-header = Awgrymiadau Chwilio
+search-suggestions-desc = Dewiswch sut fydd awgrymiadau gan beiriannau chwilio yn ymddangos.
+search-suggestions-option =
+    .label = Darparu awgrymiadau chwilio
+    .accesskey = c
+search-show-suggestions-url-bar-option =
+    .label = Dangos awgrymiadau chwilio yng nghanlyniadau'r bar lleoliad
+    .accesskey = D
+# With this option enabled, on the search results page
+# the URL will be replaced by the search terms in the address bar
+# when using the current default search engine.
+search-show-search-term-option =
+    .label = Dangos termau chwilio yn lle URL ar dudalen canlyniadau peiriannau chwilio rhagosodedig
+# This string describes what the user will observe when the system
+# prioritizes search suggestions over browsing history in the results
+# that extend down from the address bar. In the original English string,
+# "ahead" refers to location (appearing most proximate to), not time
+# (appearing before).
+search-show-suggestions-above-history-option =
+    .label = Dangos awgrymiadau chwilio o flaen hanes yng nghanlyniadau'r bar cyfeiriadau
+search-show-suggestions-private-windows =
+    .label = Dangos awgrymiadau chwilio mewn Ffenestri Preifat
+suggestions-addressbar-settings-generic2 = Newid dewisiadau awgrymiadau eraill y bar cyfeiriad
+search-suggestions-cant-show = Ni fydd awgrymiadau chwilio'n cael eu dangos yn y bar lleoliad gan eich bod wedi ffurfweddu { -brand-short-name } i byth cofio hanes.
+search-one-click-header2 = Chwilio'r Llwybrau Byr
+search-one-click-desc = Dewiswch beiriant chwilio arall sy'n ymddangos o dan y bar cyfeiriad a'r bar chwilio pan fyddwch yn cychwyn allweddair.
+search-choose-engine-column =
+    .label = Peiriannau Chwilio
+search-choose-keyword-column =
+    .label = Allweddair
+search-restore-default =
+    .label = Adfer Peiriannau Chwilio Rhagosodedig
+    .accesskey = A
+search-remove-engine =
+    .label = Tynnu
+    .accesskey = T
+search-add-engine =
+    .label = Ychwanegu
+    .accesskey = Y
+search-find-more-link = Ychwanegu peiriannau chwilio eraill
+# This warning is displayed when the chosen keyword is already in use
+# ('Duplicate' is an adjective)
+search-keyword-warning-title = Allweddair Dyblyg
+# Variables:
+#   $name (String) - Name of a search engine.
+search-keyword-warning-engine = Rydych wedi defnyddio allweddair sy'n cael ei ddefnyddio gan "{ $name }". Dewiswch un arall.
+search-keyword-warning-bookmark = Rydych wedi defnyddio allweddair sy'n cael ei ddefnyddio gan nod tudalen. Dewiswch un arall.
+
+## Containers Section
+
+containers-back-button2 =
+    .aria-label = Nôl i'r Gosodiadau
+containers-header = Tabiau Cynwysyddion
+containers-add-button =
+    .label = Ychwanegu Cynhwysydd Newydd
+    .accesskey = Y
+containers-new-tab-check =
+    .label = Dewiswch gynhwysydd ar gyfer pob tab newydd
+    .accesskey = g
+containers-settings-button =
+    .label = Gosodiadau
+containers-remove-button =
+    .label = Tynnu
+
+## Firefox Account - Signed out. Note that "Sync" and "Firefox Account" are now
+## more discrete ("signed in" no longer means "and sync is connected").
+
+sync-signedout-caption = Mynd â'ch  Gwe gyda Chi
+sync-signedout-description2 = Cydweddwch eich nodau tudalen, hanes, tabiau, cyfrineiriau, ychwanegion a dewisiadau ar draws eich holl ddyfeisiau.
+sync-signedout-account-signin3 =
+    .label = Mewngofnodi i gydweddu…
+    .accesskey = M
+# This message contains two links and two icon images.
+#   `<img data-l10n-name="android-icon"/>` - Android logo icon
+#   `<a data-l10n-name="android-link">` - Link to Android Download
+#   `<img data-l10n-name="ios-icon">` - iOS logo icon
+#   `<a data-l10n-name="ios-link">` - Link to iOS Download
+#
+# They can be moved within the sentence as needed to adapt
+# to your language, but should not be changed or translated.
+sync-mobile-promo = Llwytho Firefox i lawr ar gyfer <img data-l10n-name="android-icon"/> <a data-l10n-name="android-link">Android</a> neu <img data-l10n-name="ios-icon"/> <a data-l10n-name="ios-link">iOS</a> i gydweddu gyda'ch dyfais symudol.
+
+## Firefox Account - Signed in
+
+sync-profile-picture =
+    .tooltiptext = Newid llun proffil
+sync-sign-out =
+    .label = Allgofnodi…
+    .accesskey = A
+sync-manage-account = Rheoli cyfrif
+    .accesskey = R
+sync-signedin-unverified = { $email } wedi ei wirio.
+sync-signedin-login-failure = Ail fewngofnodwch er mwyn ailgysylltu { $email }
+sync-resend-verification =
+    .label = Ail Anfon Dilysiad
+    .accesskey = A
+sync-remove-account =
+    .label = Tynnu Cyfrif
+    .accesskey = T
+sync-sign-in =
+    .label = Mewngofnodi
+    .accesskey = M
+
+## Sync section - enabling or disabling sync.
+
+prefs-syncing-on = Cydweddu: YMLAEN
+prefs-syncing-off = Cydweddu: DIFFODD
+prefs-sync-turn-on-syncing =
+    .label = Cychwyn cydweddu…
+    .accesskey = C
+prefs-sync-offer-setup-label2 = Cydweddwch eich nodau tudalen, hanes, tabiau, cyfrineiriau, ychwanegion a dewisiadau ar draws eich holl ddyfeisiau.
+prefs-sync-now =
+    .labelnotsyncing = Cydweddu Nawr
+    .accesskeynotsyncing = N
+    .labelsyncing = Cydweddu…
+
+## The list of things currently syncing.
+
+sync-currently-syncing-heading = Rydych wrthi'n cydweddu'r eitemau hyn:
+sync-currently-syncing-bookmarks = Nodau Tudalen
+sync-currently-syncing-history = Hanes
+sync-currently-syncing-tabs = Tabiau agored
+sync-currently-syncing-logins-passwords = Mewngofnodion a chyfrineiriau
+sync-currently-syncing-addresses = Cyfeiriadau
+sync-currently-syncing-creditcards = Cardiau Credyd
+sync-currently-syncing-addons = Ychwanegion
+sync-currently-syncing-settings = Gosodiadau
+sync-change-options =
+    .label = Newid…
+    .accesskey = N
+
+## The "Choose what to sync" dialog.
+
+sync-choose-what-to-sync-dialog =
+    .title = Dewis Beth i'w Gydweddu
+    .style = width: 36em; min-height: 35em;
+    .buttonlabelaccept = Cadw Newidiadau
+    .buttonaccesskeyaccept = N
+    .buttonlabelextra2 = Datgysylltu…
+    .buttonaccesskeyextra2 = D
+sync-choose-what-to-sync-dialog3 =
+    .title = Dewis Beth i'w Gydweddu
+    .style = min-width: 36em;
+    .buttonlabelaccept = Cadw Newidiadau
+    .buttonaccesskeyaccept = N
+    .buttonlabelextra2 = Datgysylltu…
+    .buttonaccesskeyextra2 = D
+sync-engine-bookmarks =
+    .label = Nodau Tudalen
+    .accesskey = T
+sync-engine-history =
+    .label = Hanes
+    .accesskey = H
+sync-engine-tabs =
+    .label = Agor tabiau
+    .tooltiptext = Rhestr o'r hyn sydd ar agor ar bob dyfais wedi eu cydweddu
+    .accesskey = T
+sync-engine-logins-passwords =
+    .label = Mewngofnodion a chyfrineiriau
+    .tooltiptext = Enwau defnyddwyr a chyfrineiriau rydych wedi'u cadw
+    .accesskey = M
+sync-engine-addresses =
+    .label = Cyfeiriadau
+    .tooltiptext = Cyfeiriadau post rydych wedi eu cadw (bwrdd gwaith yn unig)
+    .accesskey = y
+sync-engine-creditcards =
+    .label = Cardiau Credyd
+    .tooltiptext = Enwau, rhifau a dyddiadau dod i ben (bwrdd gwaith yn unig)
+    .accesskey = r
+sync-engine-addons =
+    .label = Ychwanegion
+    .tooltiptext = Estyniadau a themâu ar gyfer Firefox bwrdd gwaith
+    .accesskey = Y
+sync-engine-settings =
+    .label = Gosodiadau
+    .tooltiptext = Gosodiadau Cyffredinol, Preifatrwydd a Diogelwch rydych wedi'u newid
+    .accesskey = G
+
+## The device name controls.
+
+sync-device-name-header = Enw Dyfais
+sync-device-name-change =
+    .label = Newid Enw'r Ddyfais…
+    .accesskey = N
+sync-device-name-cancel =
+    .label = Diddymu
+    .accesskey = D
+sync-device-name-save =
+    .label = Cadw
+    .accesskey = C
+sync-connect-another-device = Cysylltu dyfais arall
+
+## Privacy Section
+
+privacy-header = Preifatrwydd y Porwr
+
+## Privacy Section - Logins and Passwords
+
+# The search keyword isn't shown to users but is used to find relevant settings in about:preferences.
+pane-privacy-logins-and-passwords-header = Mewngofnodion a Chyfrineiriau
+    .searchkeywords = { -lockwise-brand-short-name }
+# Checkbox to control whether UI is shown to users to save or fill logins/passwords.
+forms-ask-to-save-logins =
+    .label = Gofyn i gadw mewngofnodion a chyfrineiriau ar gyfer gwefannau
+    .accesskey = G
+forms-exceptions =
+    .label = Eithriadau…
+    .accesskey = i
+forms-generate-passwords =
+    .label = Awgrymu a chynhyrchu cyfrineiriau cryf
+    .accesskey = A
+forms-breach-alerts =
+    .label = Dangos rhybuddion am gyfrineiriau ar gyfer gwefannau sydd wedi' cael tor-data
+    .accesskey = r
+forms-breach-alerts-learn-more-link = Dysgu rhagor
+relay-integration =
+    .label = Galluogi { -relay-brand-name } yn eich rheolwr cyfrineiriau { -brand-short-name }
+relay-integration-learn-more-link = Dysgu rhagor
+# Checkbox which controls filling saved logins into fields automatically when they appear, in some cases without user interaction.
+forms-fill-logins-and-passwords =
+    .label = Awtolanw mewngofnodion a chyfrineiriau
+    .accesskey = A
+forms-saved-logins =
+    .label = Mewngofnodion wedi eu Cadw…
+    .accesskey = M
+forms-primary-pw-use =
+    .label = Defnyddio Prif Gyfrinair
+    .accesskey = P
+forms-primary-pw-learn-more-link = Dysgu rhagor
+# This string uses the former name of the Primary Password feature
+# ("Master Password" in English) so that the preferences can be found
+# when searching for the old name. The accesskey is unused.
+forms-master-pw-change =
+    .label = Newid y Prif Gyfrinair…
+    .accesskey = N
+forms-primary-pw-change =
+    .label = Newid y Prif Gyfrinair…
+    .accesskey = N
+# Leave this message empty if the translation for "Primary Password" matches
+# "Master Password" in your language. If you're editing the FTL file directly,
+# use { "" } as the value.
+forms-primary-pw-former-name = { "" }
+forms-primary-pw-fips-title = Rydych ym modd FIPS. Mae FIPS angen Prif Gyfrinair nad yw'n wag.
+forms-master-pw-fips-desc = Methu Newid eich Cyfrinair
+forms-windows-sso =
+    .label = Caniatáu mewngofnodiad unigol cyfrifon Microsoft, gwaith ac ysgol.
+forms-windows-sso-learn-more-link = Dysgu rhagor
+forms-windows-sso-desc = Rheoli cyfrifon yn eich gosodiadau dyfais
+
+## OS Authentication dialog
+
+# This message can be seen by trying to add a Primary Password.
+primary-password-os-auth-dialog-message-win = I greu Prif Gyfrinair, nodwch fanylion eich mewngofnodi Windows. Mae hyn yn helpu i ddiogelu eich cyfrifon.
+# This message can be seen by trying to add a Primary Password.
+# The macOS strings are preceded by the operating system with "Firefox is trying to "
+# and includes subtitle of "Enter password for the user "xxx" to allow this." These
+# notes are only valid for English. Please test in your locale.
+primary-password-os-auth-dialog-message-macosx = creu Prif Gyfrinair
+master-password-os-auth-dialog-caption = { -brand-full-name }
+
+## Privacy Section - History
+
+history-header = Hanes
+# This label is followed, on the same line, by a dropdown list of options
+# (Remember history, etc.).
+# In English it visually creates a full sentence, e.g.
+# "Firefox will" + "Remember history".
+#
+# If this doesn't work for your language, you can translate this message:
+#   - Simply as "Firefox", moving the verb into each option.
+#     This will result in "Firefox" + "Will remember history", etc.
+#   - As a stand-alone message, for example "Firefox history settings:".
+history-remember-label = Bydd { -brand-short-name } yn
+    .accesskey = B
+history-remember-option-all =
+    .label = Cofio hanes
+history-remember-option-never =
+    .label = Peidio cofio hanes
+history-remember-option-custom =
+    .label = Defnyddio gosodiadau cyfaddas ar gyfer hanes
+history-remember-description = Bydd { -brand-short-name } yn cofio eich hanes pori, llwytho i lawr, ffurflenni a chwilio.
+history-dontremember-description = Bydd { -brand-short-name } yn defnyddio'r un gosodiadau â phori preifat, ond ni fydd yn cofio unrhyw hanes wrth i chi bori'r We.
+history-private-browsing-permanent =
+    .label = Defnyddio'r modd pori preifat bob tro
+    .accesskey = p
+history-remember-browser-option =
+    .label = Cofio hanes pori a llwytho i lawr
+    .accesskey = h
+history-remember-search-option =
+    .label = Cofio hanes chwilio a ffurflen
+    .accesskey = C
+history-clear-on-close-option =
+    .label = Clirio hanes pan fydd { -brand-short-name } yn cau
+    .accesskey = l
+history-clear-on-close-settings =
+    .label = Gosodiadau…
+    .accesskey = G
+history-clear-button =
+    .label = Clirio Hanes…
+    .accesskey = H
+
+## Privacy Section - Site Data
+
+sitedata-header = Cwcis a Data Gwefan
+sitedata-total-size-calculating = Cyfrifo maint data gwefan a storfa dros dro…
+# Variables:
+#   $value (Number) - Value of the unit (for example: 4.6, 500)
+#   $unit (String) - Name of the unit (for example: "bytes", "KB")
+sitedata-total-size = Mae'r cwcis, data gwefan a storfa dros dro yn defnyddio { $value } { $unit } o le ar ddisg ar hyn o bryd.
+sitedata-learn-more = Dysgu rhagor
+sitedata-delete-on-close =
+    .label = Dileu cwcis a data'r wefan pan fydd { -brand-short-name } yn cau
+    .accesskey = D
+sitedata-delete-on-close-private-browsing = Yn y modd pori preifat parhaol, bydd cwcis a data'r wefan yn cael eu clirio bob tro pan fydd { -brand-short-name } yn cau.
+sitedata-allow-cookies-option =
+    .label = Derbyn cwcis a data gan wefannau
+    .accesskey = D
+sitedata-disallow-cookies-option =
+    .label = Rhwystro cwcis a data gwefan
+    .accesskey = R
+# This label means 'type of content that is blocked', and is followed by a drop-down list with content types below.
+# The list items are the strings named sitedata-block-*-option*.
+sitedata-block-desc = Mathau wedi'u rhwystro
+    .accesskey = M
+sitedata-option-block-cross-site-trackers =
+    .label = Tracwyr traws-gwefan
+sitedata-option-block-cross-site-tracking-cookies =
+    .label = Cwcis tracio traws-gwefan
+sitedata-option-block-cross-site-cookies =
+    .label = Cwcis tracio traws-gwefan, ac ynysu cwcis traws-gwefan eraill
+sitedata-option-block-unvisited =
+    .label = Cwcis o wefannau heb ymweld â nhw
+sitedata-option-block-all-third-party =
+    .label = Pob cwci trydydd parti (gall achosi i wefannau i dorri)
+sitedata-option-block-all-cross-site-cookies =
+    .label = Pob cwci traws-safle (gall achosi i wefannau dorri)
+sitedata-option-block-all =
+    .label = Pob cwci (bydd yn achosi i wefannau dorri)
+sitedata-clear =
+    .label = Clirio Data…
+    .accesskey = l
+sitedata-settings =
+    .label = Rheoli Data…
+    .accesskey = R
+sitedata-cookies-exceptions =
+    .label = Rheoli Eithriadau…
+    .accesskey = R
+
+## Privacy Section - Address Bar
+
+addressbar-header = Bar Cyfeiriadau
+addressbar-suggest = Pan yn defnyddio'r bar cyfeiriad, cynnig
+addressbar-locbar-history-option =
+    .label = Hanes pori
+    .accesskey = p
+addressbar-locbar-bookmarks-option =
+    .label = Nodau Tudalen
+    .accesskey = N
+addressbar-locbar-openpage-option =
+    .label = Tabiau agored
+    .accesskey = T
+# Shortcuts refers to the shortcut tiles on the new tab page, previously known as top sites. Translation should be consistent.
+addressbar-locbar-shortcuts-option =
+    .label = Llwybrau Byr
+    .accesskey = L
+addressbar-locbar-topsites-option =
+    .label = Hoff wefannau
+    .accesskey = H
+addressbar-locbar-engines-option =
+    .label = Peiriannau chwilio
+    .accesskey = P
+addressbar-locbar-quickactions-option =
+    .label = Gweithredoedd cyflym
+    .accesskey = c
+addressbar-suggestions-settings = Newid dewisiadau am awgrymiadau peiriannau chwilio
+addressbar-quickactions-learn-more = Dysgu rhagor
+
+## Privacy Section - Content Blocking
+
+content-blocking-enhanced-tracking-protection = Diogelwch Uwch Rhag Tracio
+content-blocking-section-top-level-description = Mae tracwyr yn eich dilyn ar-lein i gasglu gwybodaeth am eich arferion pori a'ch diddordebau. Mae { -brand-short-name } yn rhwystro llawer o'r tracwyr hyn a sgriptiau maleisus eraill.
+content-blocking-learn-more = Dysgu Rhagor
+content-blocking-fpi-incompatibility-warning = Rydych yn defnyddio Ynysu Parti Cyntaf (FPI), sy’n gwrthwneud rhai o osodiadau cwci { -brand-short-name } ’.
+
+## These strings are used to define the different levels of
+## Enhanced Tracking Protection.
+
+# "Standard" in this case is an adjective, meaning "default" or "normal".
+enhanced-tracking-protection-setting-standard =
+    .label = Safonol
+    .accesskey = S
+enhanced-tracking-protection-setting-strict =
+    .label = Llym
+    .accesskey = L
+enhanced-tracking-protection-setting-custom =
+    .label = Cyfaddasu
+    .accesskey = C
+
+##
+
+content-blocking-etp-standard-desc = Cydbwysedd rhwng diogelwch a pherfformiad. Bydd tudalennau'n llwytho fel arfer.
+content-blocking-etp-strict-desc = Diogelwch cryfach, ond gall achosi i rai gwefannau neu gynnwys dorri.
+content-blocking-etp-custom-desc = Dewiswch pa dracwyr a sgriptiau i'w rhwystro.
+content-blocking-etp-blocking-desc = Mae { -brand-short-name } yn rhwystro'r canlynol:
+content-blocking-private-windows = Tracio cynnwys mewn Ffenestri Preifat
+content-blocking-cross-site-cookies-in-all-windows = Cwcis traws-safle ym mhob ffenestr (yn cynnwys cwcis tracio)
+content-blocking-cross-site-cookies-in-all-windows2 = Cwcis traws-safle ym mhob ffenestr
+content-blocking-cross-site-tracking-cookies = Cwcis tracio traws-gwefan
+content-blocking-all-cross-site-cookies-private-windows = Cwcis traws-safle mewn Ffenestri Preifat
+content-blocking-cross-site-tracking-cookies-plus-isolate = Cwcis tracio traws-safle, ac ynysu'r cwcis sy'n weddill
+content-blocking-social-media-trackers = Tracwyr cyfryngau cymdeithasol
+content-blocking-all-cookies = Pob cwci
+content-blocking-unvisited-cookies = Cwcis o safleoedd heb ymweld â nhw
+content-blocking-all-windows-tracking-content = Tracio cynnwys ym mhob ffenestr
+content-blocking-all-third-party-cookies = Pob cwci trydydd parti
+content-blocking-all-cross-site-cookies = Pob cwci traws-gwefan
+content-blocking-cryptominers = Cryptogloddwyr
+content-blocking-fingerprinters = Bysbrintwyr
+# "Test pilot" is used as a verb. Possible alternatives:
+# "Be the first to try", "Join an early experiment".
+content-blocking-etp-standard-tcp-rollout-checkbox =
+    .label = Rhowch brawf ar ein profiad preifatrwydd mwyaf pwerus erioed
+    .accesskey = R
+
+# The tcp-rollout strings are no longer used for the rollout but for tcp-by-default in the standard section
+
+# "Contains" here means "isolates", "limits".
+content-blocking-etp-standard-tcp-rollout-description = Mae Diogelwch Cwcis Llwyr yn cyfyngu cwcis i'r wefan rydych chi arni, felly nid yw tracwyr yn gallu eu defnyddio i'ch dilyn rhwng gwefannau.
+content-blocking-etp-standard-tcp-rollout-learn-more = Dysgu rhagor
+content-blocking-etp-standard-tcp-title = Yn cynnwys Diogelwch Cwcis Llwyr, ein nodwedd preifatrwydd mwyaf pwerus erioed
+content-blocking-warning-title = Rhybudd!
+content-blocking-and-isolating-etp-warning-description-2 = Gall y gosodiad hwn beri i rai gwefannau beidio a dangos cynnwys na gweithio'n iawn. Os yw gwefan yn ymddangos wedi torri, efallai yr hoffech chi ddiffodd diogelu rhag tracio i'r wefan honno lwytho'r holl gynnwys.
+content-blocking-warning-learn-how = Dysgu sut
+content-blocking-reload-description = Bydd angen ail lwytho'ch tabiau i osod y newidiadau hyn.
+content-blocking-reload-tabs-button =
+    .label = Ail lwytho Pob Tab
+    .accesskey = A
+content-blocking-tracking-content-label =
+    .label = Cynnwys tracio
+    .accesskey = t
+content-blocking-tracking-protection-option-all-windows =
+    .label = Ym mhob ffenestr
+    .accesskey = f
+content-blocking-option-private =
+    .label = Dim ond mewn Ffenestri Preifat
+    .accesskey = P
+content-blocking-tracking-protection-change-block-list = Newid y rhestr rhwystro
+content-blocking-cookies-label =
+    .label = Cwcis
+    .accesskey = C
+content-blocking-expand-section =
+    .tooltiptext = Rhagor o wybodaeth
+# Cryptomining refers to using scripts on websites that can use a computer’s resources to mine cryptocurrency without a user’s knowledge.
+content-blocking-cryptominers-label =
+    .label = Cryptogloddwyr
+    .accesskey = y
+# Browser fingerprinting is a method of tracking users by the configuration and settings information (their "digital fingerprint")
+# that is visible to websites they browse, rather than traditional tracking methods such as IP addresses and unique cookies.
+content-blocking-fingerprinters-label =
+    .label = Bysbrintwyr
+    .accesskey = B
+
+## Privacy Section - Tracking
+
+tracking-manage-exceptions =
+    .label = Rheoli Eithriadau…
+    .accesskey = R
+
+## Privacy Section - Permissions
+
+permissions-header = Caniatâd
+permissions-location = Lleoliad
+permissions-location-settings =
+    .label = Gosodiadau…
+    .accesskey = d
+permissions-xr = Rhithrealaeth
+permissions-xr-settings =
+    .label = Gosodiadau…
+    .accesskey = G
+permissions-camera = Camera
+permissions-camera-settings =
+    .label = Gosodiadau…
+    .accesskey = s
+permissions-microphone = Meicroffon
+permissions-microphone-settings =
+    .label = Gosodiadau…
+    .accesskey = o
+permissions-notification = Hysbysiadau
+permissions-notification-settings =
+    .label = Gosodiadau…
+    .accesskey = G
+permissions-notification-link = Dysgu rhagor
+permissions-notification-pause =
+    .label = Oedi fy hysbysiadau tan { -brand-short-name } ailgychwyn
+    .accesskey = O
+permissions-autoplay = Awtochwarae
+permissions-autoplay-settings =
+    .label = Gosodiadau…
+    .accesskey = G
+permissions-block-popups =
+    .label = Rhwystro ffenestri llamlen
+    .accesskey = R
+# "popup" is a misspelling that is more popular than the correct spelling of
+# "pop-up" so it's included as a search keyword, not displayed in the UI.
+permissions-block-popups-exceptions-button =
+    .label = Eithriadau…
+    .accesskey = E
+    .searchkeywords = llamlenni
+permissions-addon-install-warning =
+    .label = Rhybuddio pan fydd gwefan yn ceisio gosod ychwanegion
+    .accesskey = y
+permissions-addon-exceptions =
+    .label = Eithriadau…
+    .accesskey = E
+
+## Privacy Section - Data Collection
+
+collection-header = Casglu Data a'r Defnydd o { -brand-short-name }
+collection-description = Rydym yn ceisio darparu dewisiadau i chi a chasglu dim ond beth sydd ei angen arnom i ddarparu a gwella { -brand-short-name } ar gyfer pawb. Rydym yn gofyn caniatâd bob tro cyn derbyn manylion personol.
+collection-privacy-notice = Rhybudd Preifatrwydd
+collection-health-report-telemetry-disabled = Nid ydych bellach yn caniatáu i { -vendor-short-name } ddal data technegol a rhyngweithiol. Bydd holl ddata'r gorffennol yn cael ei ddileu cyn pen 30 diwrnod.
+collection-health-report-telemetry-disabled-link = Dysgu rhagor
+collection-health-report =
+    .label = Caniatáu i { -brand-short-name } anfon data technegol a rhyngweithio i { -vendor-short-name }
+    .accesskey = r
+collection-health-report-link = Dysgu rhagor
+collection-studies =
+    .label = Caniatáu i { -brand-short-name } osod a rhedeg astudiaethau
+collection-studies-link = Gweld astudiaethau { -brand-short-name }
+addon-recommendations =
+    .label = Caniatáu i { -brand-short-name } wneud argymhellion personol am estyniadau
+addon-recommendations-link = Dysgu rhagor
+# This message is displayed above disabled data sharing options in developer builds
+# or builds with no Telemetry support available.
+collection-health-report-disabled = Mae adrodd ar ddata wedi ei analluogi ar gyfer ffurfweddiad yr adeiledd hwn
+collection-backlogged-crash-reports-with-link = Caniatáu i { -brand-short-name } anfon adroddiadau chwalu sydd wedi'u crynhoi ar eich rhan <a data-l10n-name="crash-reports-link">Dysgu rhagor</a>
+    .accesskey = C
+privacy-segmentation-section-header = Nodweddion newydd sy'n gwella eich pori
+privacy-segmentation-section-description = Pan fyddwn yn cynnig nodweddion sy'n defnyddio'ch data i roi profiad mwy personol i chi:
+privacy-segmentation-radio-off =
+    .label = Defnyddio argymhellion { -brand-product-name }
+privacy-segmentation-radio-on =
+    .label = Dangos gwybodaeth fanwl
+
+## Privacy Section - Security
+##
+## It is important that wording follows the guidelines outlined on this page:
+## https://developers.google.com/safe-browsing/developers_guide_v2#AcceptableUsage
+
+security-header = Diogelwch
+security-browsing-protection = Diogelwch rhag Cynnwys Twyllodrus a Meddalwedd Peryglus
+security-enable-safe-browsing =
+    .label = Rhwystro cynnwys peryglus a thwyllodrus
+    .accesskey = R
+security-enable-safe-browsing-link = Dysgu rhagor
+security-block-downloads =
+    .label = Rhwystro llwytho i lawr peryglus
+    .accesskey = p
+security-block-uncommon-software =
+    .label = Rhybuddio fi am feddalwedd digroeso ac anghyffredin
+    .accesskey = a
+
+## Privacy Section - Certificates
+
+certs-header = Tystysgrifau
+certs-enable-ocsp =
+    .label = Gofyn i weinyddion atebwr OCSP i gadarnhau dilysrwydd cyfredol y tystysgrifau
+    .accesskey = G
+certs-view =
+    .label = Darllen Tystysgrifau…
+    .accesskey = D
+certs-devices =
+    .label = Dyfeisiau Diogelwch…
+    .accesskey = y
+space-alert-over-5gb-settings-button =
+    .label = Agor y Gosodiadau
+    .accesskey = A
+space-alert-over-5gb-message2 = <strong>Mae { -brand-short-name } yn brin o le ar ddisg.</strong> Efallai na fydd cynnwys gwefan yn cael ei ddangos yn iawn. Mae modd i chi glirio data wedi ei storio yn Dewisiadau > Preifatrwydd a Diogelwch > Cwcis a Data Gwefan.
+space-alert-under-5gb-message2 = <strong>Mae { -brand-short-name } yn brin o le ar ddisg.</strong> Efallai na fydd cynnwys gwefan yn cael ei ddangos yn iawn. Ewch i “Learn More” i wella'r defnydd o'r disg ar gyfer gwell profiad pori.
+
+## Privacy Section - HTTPS-Only
+
+httpsonly-header = Modd HTTPS-yn-Unig
+httpsonly-description = Mae HTTPS yn darparu cysylltiad diogel, wedi'i amgryptio rhwng  { -brand-short-name } a'r gwefannau rydych chi'n ymweld â nhw. Mae'r mwyafrif o wefannau yn cefnogi HTTPS, ac os yw Modd HTTPS-yn-Unig wedi'i alluogi, yna bydd { -brand-short-name } yn uwchraddio'r holl gysylltiadau â HTTPS.
+httpsonly-learn-more = Dysgu rhagor
+httpsonly-radio-enabled =
+    .label = Galluogi Modd HTTPS-yn-Unig ym mhob ffenestr
+httpsonly-radio-enabled-pbm =
+    .label = Galluogi Modd HTTPS-yn-Unig mewn ffenestri preifat yn unig
+httpsonly-radio-disabled =
+    .label = Peidio â galluogi Modd HTTPS-yn-Unig
+
+## The following strings are used in the Download section of settings
+
+desktop-folder-name = Bwrdd Gwaith
+downloads-folder-name = Llwythi
+choose-download-folder-title = Dewis Ffolder Llwytho i Lawr:
diff --git a/l10n-cy/browser/browser/preferences/selectBookmark.ftl b/l10n-cy/browser/browser/preferences/selectBookmark.ftl
new file mode 100644
index 0000000000..e58ae0a43e
--- /dev/null
+++ b/l10n-cy/browser/browser/preferences/selectBookmark.ftl
@@ -0,0 +1,13 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+select-bookmark-window =
+    .title = Gosod Tudalen Cartref
+    .style = width: 32em;
+
+select-bookmark-window2 =
+    .title = Gosod Tudalen Cartref
+    .style = min-width: 32em;
+
+select-bookmark-desc = Dewiswch Nod Tudalen i fod yn Dudalen Cartref. Os fyddwch yn dewis ffolder, bydd y Nodau Tudalen yn y ffolder yn cael eu hagor mewn Tabiau.
diff --git a/l10n-cy/browser/browser/preferences/siteDataSettings.ftl b/l10n-cy/browser/browser/preferences/siteDataSettings.ftl
new file mode 100644
index 0000000000..a4ba5ec9ae
--- /dev/null
+++ b/l10n-cy/browser/browser/preferences/siteDataSettings.ftl
@@ -0,0 +1,67 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+## Settings
+
+site-data-settings-window =
+    .title = Rheoli Cwcis a Data Gwefan
+
+site-data-settings-description = Mae'r gwefannau canlynol yn cadw cwcis a data gwefan ar eich cyfrifiadur. Mae { -brand-short-name } yn cadw data o wefannau sydd â storio parhaus nes i chi eu dileu, ac yn dileu data o wefannau sydd heb storfa parhaus yn ôl yr angen am le ar ddisg.
+
+site-data-search-textbox =
+    .placeholder = Chwilio gwefannau
+    .accesskey = C
+
+site-data-column-host =
+    .label = Gwefan
+site-data-column-cookies =
+    .label = Cwcis
+site-data-column-storage =
+    .label = Storfa
+site-data-column-last-used =
+    .label = Defnyddiwyd Diwethaf
+
+# This label is used in the "Host" column for local files, which have no host.
+site-data-local-file-host = (ffeil leol)
+
+site-data-remove-selected =
+    .label = Tynnu'r Dewis
+    .accesskey = T
+
+site-data-settings-dialog =
+    .buttonlabelaccept = Cadw Newidiadau
+    .buttonaccesskeyaccept = a
+
+# Variables:
+#   $value (Number) - Value of the unit (for example: 4.6, 500)
+#   $unit (String) - Name of the unit (for example: "bytes", "KB")
+site-storage-usage =
+    .value = { $value } { $unit }
+site-storage-persistent =
+    .value = { site-storage-usage.value } (Parhaus)
+
+site-data-remove-all =
+    .label = Tynnu Popeth
+    .accesskey = P
+
+site-data-remove-shown =
+    .label = Tynnu Popeth Dangoswyd
+    .accesskey = y
+
+## Removing
+
+site-data-removing-dialog =
+    .title = { site-data-removing-header }
+    .buttonlabelaccept = Tynnu
+
+site-data-removing-header = Tynnu Cwcis a Data Gwefan
+
+site-data-removing-desc = Gall dynnu cwcis a data gwefan eich allgofnodi o wefannau. Ydych chi'n siŵr eich bod am wneud y newidiadau hyn?
+
+# Variables:
+#   $baseDomain (String) - The single domain for which data is being removed
+site-data-removing-single-desc = Efallai y bydd dileu cwcis a data gwefan yn eich allgofnodi o wefannau. Ydych chi'n siŵr eich bod chi am gael gwared â chwcis a data gwefan ar gyfer <strong>{ $baseDomain }</strong>?
+
+site-data-removing-table = Bydd cwcis a data gwefan yn cael eu tynnu o'r gwefannau canlynol
diff --git a/l10n-cy/browser/browser/preferences/translation.ftl b/l10n-cy/browser/browser/preferences/translation.ftl
new file mode 100644
index 0000000000..2317ede426
--- /dev/null
+++ b/l10n-cy/browser/browser/preferences/translation.ftl
@@ -0,0 +1,44 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+translation-window =
+    .title = Eithriadau - Cyfieithiad
+    .style = width: 36em
+
+translation-window2 =
+    .title = Eithriadau - Cyfieithiad
+    .style = min-width: 36em
+
+translation-close-key =
+    .key = w
+
+translation-languages-disabled-desc = Ni fydd cyfieithiad yn cael ei gynnig ar gyfer yr ieithoedd canlynol
+
+translation-languages-column =
+    .label = Iaith
+
+translation-languages-button-remove =
+    .label = Tynnu Iaith
+    .accesskey = T
+
+translation-languages-button-remove-all =
+    .label = Tynnu Pob Iaith
+    .accesskey = y
+
+translation-sites-disabled-desc = Ni fydd cyfieithiad yn cael ei gynnig o'r gwefannau canlynol
+
+translation-sites-column =
+    .label = Gwefannau
+
+translation-sites-button-remove =
+    .label = Tynnu'r Wefan
+    .accesskey = W
+
+translation-sites-button-remove-all =
+    .label = Tynnu Pob Gwefan
+    .accesskey = G
+
+translation-dialog =
+    .buttonlabelaccept = Cau
+    .buttonaccesskeyaccept = C
diff --git a/l10n-cy/browser/browser/profile/default-bookmarks.ftl b/l10n-cy/browser/browser/profile/default-bookmarks.ftl
new file mode 100644
index 0000000000..bcc65320bb
--- /dev/null
+++ b/l10n-cy/browser/browser/profile/default-bookmarks.ftl
@@ -0,0 +1,53 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+# This file intentionally uses hard-coded brand names instead of Fluent terms.
+# This approach minimizes issues across multiple release channels and rebranded
+# versions.
+
+default-bookmarks-title = Nodau Tudalen
+default-bookmarks-heading = Nodau Tudalen
+
+default-bookmarks-toolbarfolder = Ffolder Bar Offer Nodau Tudalen
+default-bookmarks-toolbarfolder-description = Ychwanegu nodau tudalen i'r ffolder hwn i'w gweld yn cael eu dangos ar y Bar Offer Nodau Tudalen
+
+# link title for https://www.mozilla.org/firefox/central/
+default-bookmarks-getting-started = Cychwyn Arni
+
+# Firefox links folder name
+default-bookmarks-firefox-heading = Mozilla Firefox
+
+# link title for https://www.mozilla.org/firefox/help/
+default-bookmarks-firefox-get-help = Derbyn Cymorth
+
+# link title for https://www.mozilla.org/firefox/customize/
+default-bookmarks-firefox-customize = Cyfaddasu Firefox
+
+# link title for https://www.mozilla.org/contribute/
+default-bookmarks-firefox-community = Cyfranogi
+
+# link title for https://www.mozilla.org/about/
+default-bookmarks-firefox-about = Amdanom Ni
+
+# Firefox Nightly links folder name
+default-bookmarks-nightly-heading = Adnoddau Firefox Nightly
+
+# Nightly builds only, link title for https://blog.nightly.mozilla.org/
+default-bookmarks-nightly-blog = Blog Firefox Nightly
+
+# Nightly builds only, link title for https://bugzilla.mozilla.org/
+default-bookmarks-bugzilla = Traciwr Gwallau Mozilla
+
+# Nightly builds only, link title for https://developer.mozilla.org/
+default-bookmarks-mdn = Rhwydwaith Datblygwyr Mozilla
+
+# Nightly builds only, link title for https://addons.mozilla.org/firefox/addon/nightly-tester-tools/
+default-bookmarks-nightly-tester-tools = Offer Profi Nightly
+
+# Nightly builds only, link title for about:crashes
+default-bookmarks-crashes = Eich holl chwalfeydd
+
+# Nightly builds only, link title for https://planet.mozilla.org/
+default-bookmarks-planet = Planet Mozilla
diff --git a/l10n-cy/browser/browser/protections.ftl b/l10n-cy/browser/browser/protections.ftl
new file mode 100644
index 0000000000..4ea631e780
--- /dev/null
+++ b/l10n-cy/browser/browser/protections.ftl
@@ -0,0 +1,294 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# Variables:
+#   $count (Number) - Number of tracking events blocked.
+graph-week-summary =
+    { $count ->
+        [zero] Mae { -brand-short-name } wedi rhwystro { $count } tracwyr yn ystod yr wythnos ddiwethaf
+        [one] Mae { -brand-short-name } wedi rhwystro { $count } traciwr yn ystod yr wythnos ddiwethaf
+        [two] Mae { -brand-short-name } wedi rhwystro { $count } draciwr yn ystod yr wythnos ddiwethaf
+        [few] Mae { -brand-short-name } wedi rhwystro { $count } traciwr yn ystod yr wythnos ddiwethaf
+        [many] Mae { -brand-short-name } wedi rhwystro { $count } traciwr yn ystod yr wythnos ddiwethaf
+       *[other] Mae { -brand-short-name } wedi rhwystro { $count } traciwr yn ystod yr wythnos ddiwethaf
+    }
+
+# Variables:
+#   $count (Number) - Number of tracking events blocked.
+#   $earliestDate (Number) - Unix timestamp in ms, representing a date. The
+# earliest date recorded in the database.
+graph-total-tracker-summary =
+    { $count ->
+        [zero] <b>{ $count }</b> tracwyr wedi eu rhwystro ers{ DATETIME($earliestDate, day: "numeric", month: "long", year: "numeric") }
+        [one] <b>{ $count }</b> traciwr wedi ei rwystro ers{ DATETIME($earliestDate, day: "numeric", month: "long", year: "numeric") }
+        [two] <b>{ $count }</b> draciwr wedi eu rwystro ers{ DATETIME($earliestDate, day: "numeric", month: "long", year: "numeric") }
+        [few] <b>{ $count }</b> traciwr wedi eu rwystro ers{ DATETIME($earliestDate, day: "numeric", month: "long", year: "numeric") }
+        [many] <b>{ $count }</b> thraciwr wedi eu rwystro ers{ DATETIME($earliestDate, day: "numeric", month: "long", year: "numeric") }
+       *[other] <b>{ $count }</b> traciwr wedi eu rwystro ers{ DATETIME($earliestDate, day: "numeric", month: "long", year: "numeric") }
+    }
+
+# Text displayed instead of the graph when in Private Mode
+graph-private-window = Mae { -brand-short-name } yn parhau i rwystro tracwyr mewn Ffenestri Preifat, ond nid yw'n cadw cofnod o'r hyn gafodd ei rwystro.
+# Weekly summary of the graph when the graph is empty in Private Mode
+graph-week-summary-private-window = Tracwyr rhwystrodd { -brand-short-name } yr wythnos hon
+
+protection-report-webpage-title = Bwrdd Gwaith Diogelwch
+protection-report-page-content-title = Bwrdd Gwaith Diogelwch
+# This message shows when all privacy protections are turned off, which is why we use the word "can", Firefox is able to protect your privacy, but it is currently not.
+protection-report-page-summary = Gall { -brand-short-name } ddiogelu eich preifatrwydd y tu ôl i'r llenni wrth i chi bori. Mae hwn yn grynodeb wedi'i bersonoli o'r diogelwch hynny, gan gynnwys offer i reoli eich diogelwch ar-lein.
+# This message shows when at least some protections are turned on, we are more assertive compared to the message above, Firefox is actively protecting you.
+protection-report-page-summary-default = Mae { -brand-short-name } yn diogelu eich preifatrwydd y tu ôl i'r llenni wrth i chi bori. Mae hwn yn grynodeb wedi'i bersonoli o'r diogelwch hynny, gan gynnwys offer i reoli'ch diogelwch ar-lein.
+
+protection-report-settings-link = Rheoli eich gosodiadau preifatrwydd a diogelwch
+
+etp-card-title-always = Diogelwch Uwch Rhag Tracio: Ymlaen Drwy'r Amser
+etp-card-title-custom-not-blocking = Diogelwch Uwch Rhag Tracio: I FFWRDD
+etp-card-content-description = Mae { -brand-short-name } yn atal cwmnïau rhag eich dilyn yn gyfrinachol o amgylch y we, yn awtomatig.
+protection-report-etp-card-content-custom-not-blocking = Mae'r holl ddiogelu wedi'u diffodd ar hyn o bryd. Dewiswch pa dracwyr i'w rhwystro trwy reoli eich gosodiadau diogelu { -brand-short-name }.
+protection-report-manage-protections = Rheoli Gosodiadau
+
+# This string is used to label the X axis of a graph. Other days of the week are generated via Intl.DateTimeFormat,
+# capitalization for this string should match the output for your locale.
+graph-today = Heddiw
+
+# This string is used to describe the graph for screenreader users.
+graph-legend-description = Graff sy'n cynnwys cyfanswm nifer pob math o draciwr gafodd ei rwystro yr wythnos hon.
+
+social-tab-title = Tracwyr Cyfryngau Cymdeithasol
+social-tab-contant = Mae rhwydweithiau cymdeithasol yn gosod tracwyr ar wefannau eraill i ddilyn yr hyn rydych chi'n ei wneud, ei weld, a'i wylio ar-lein. Mae hyn yn caniatáu i gwmnïau cyfryngau cymdeithasol ddysgu rhagor amdanoch chi y tu hwnt i'r hyn rydych chi'n ei rannu ar eich proffiliau cyfryngau cymdeithasol. <a data-l10n-name="learn-more-link">Dysgu rhagor</a>
+
+cookie-tab-title = Cwcis Tracio Traws-Gwefan
+cookie-tab-content = Mae'r cwcis hyn yn eich dilyn o wefan i wefan i gasglu data am yr hyn rydych chi'n ei wneud ar-lein. Mae nhw'n cael eu gosod gan drydydd partïon fel hysbysebwyr a chwmnïau dadansoddeg. Mae rhwystro cwcis tracio traws-safle yn lleihau'r nifer o hysbysebion sy'n eich dilyn. <a data-l10n-name="learn-more-link">Dysgu rhagor</a>
+
+tracker-tab-title = Tracio Cynnwys
+tracker-tab-description = Gall gwefannau lwytho hysbysebion allanol, fideos a chynnwys eraill sy'n cynnwys cod tracio. Gall rhwystro cynnwys tracio helpu gwefannau i lwytho'n gynt, ond efallai na fydd rhai botymau, ffurflenni a meysydd mewngofnodi'n gweithio. <a data-l10n-name="learn-more-link">Dysgu rhagor</a>
+
+fingerprinter-tab-title = Bysbrintwyr
+fingerprinter-tab-content = Mae bysbrintwyr yn casglu gosodiadau o'ch porwr a'ch cyfrifiadur i greu proffil ohonoch. Gan ddefnyddio'r olion bys digidol hwn, mae nhw'n gallu'ch tracio ar draws gwahanol wefannau. <a data-l10n-name="learn-more-link">Dysgu rhagor</a>
+
+cryptominer-tab-title = Cryptogloddwyr
+cryptominer-tab-content = Mae cryptogloddwyr yn defnyddio pŵer cyfrifiadurol eich system i gloddio arian digidol. Mae sgriptiau cryptogloddio yn gwagio eich batri, arafu eich cyfrifiadur, a gall gynyddu eich bil trydan. <a data-l10n-name="learn-more-link">Dysgu rhagor</a>
+
+protections-close-button2 =
+    .aria-label = Cau
+    .title = Cau
+
+mobile-app-title = Rhwystrwch dracwyr hysbysebion ar draws rhagor o ddyfeisiau
+mobile-app-card-content = Defnyddiwch y porwr symudol gydag diogelwch mewnol rhag tracio gan hysbysebion.
+mobile-app-links = Porwr { -brand-product-name } ar gyfer <a data-l10n-name="android-mobile-inline-link">Android</a> a <a data-l10n-name="ios-mobile-inline-link">iOS</a>
+
+lockwise-title = Peidiwch byth ag anghofio cyfrinair eto
+passwords-title-logged-in = Rheoli'ch cyfrineiriau
+passwords-header-content = Mae { -brand-product-name } yn cadw'ch cyfrineiriau yn ddiogel yn eich porwr.
+lockwise-header-content-logged-in = Cadwch a chydweddwch eich cyfrineiriau'n ddiogel i'ch holl ddyfeisiau.
+protection-report-passwords-save-passwords-button = Cadw Cyfrineiriau
+    .title = Cadw Cyfrineiriau
+protection-report-passwords-manage-passwords-button = Rheoli Cyfrineiriau
+    .title = Rheoli Cyfrineiriau
+
+
+# Variables:
+# $count (Number) - Number of passwords exposed in data breaches.
+lockwise-scanned-text-breached-logins =
+    { $count ->
+        [zero] Efallai bod { $count } cyfrineiriau wedi cael eu hamlygu mewn tor-data.
+        [one] Efallai bod i 1 cyfrinair wedi cael ei amlygu mewn tor-data.
+        [two] Efallai bod { $count } gyfrinair wedi cael eu hamlygu mewn tor-data.
+        [few] Efallai bod { $count } cyfrinair wedi cael eu hamlygu mewn tor-data.
+        [many] Efallai bod { $count } chyfrinair wedi cael eu hamlygu mewn tor-data.
+       *[other] Efallai bod { $count } cyfrinair wedi cael eu hamlygu mewn tor-data.
+    }
+
+# While English doesn't use the number in the plural form, you can add $count to your language
+# if needed for grammatical reasons.
+# Variables:
+# $count (Number) - Number of passwords stored in Lockwise.
+lockwise-scanned-text-no-breached-logins =
+    { $count ->
+        [zero] Mae'ch cyfrineiriau'n cael eu cadw'n ddiogel.
+        [one] Mae 1 cyfrinair yn cael ei gadw'n ddiogel.
+        [two] Mae'ch cyfrineiriau'n cael eu cadw'n ddiogel.
+        [few] Mae'ch cyfrineiriau'n cael eu cadw'n ddiogel.
+        [many] Mae'ch cyfrineiriau'n cael eu cadw'n ddiogel.
+       *[other] Mae'ch cyfrineiriau'n cael eu cadw'n ddiogel.
+    }
+lockwise-how-it-works-link = Sut mae'n gweithio
+
+monitor-title = Bod yn effro i dor-data.
+monitor-link = Sut mae'n gweithio
+monitor-header-content-no-account = Edrychwch ar { -monitor-brand-name } i weld a ydych chi wedi bod yn rhan o dor-data a chael rhybuddion am dor-data newydd.
+monitor-header-content-signed-in = Mae { -monitor-brand-name } yn eich rhybuddio os yw'ch manylion wedi ymddangos mewn tor-data hysbys
+monitor-sign-up-link = Cofrestrwch am Rybuddion Tor-data
+    .title = Cofrestrwch am rybuddion tor-data ar { -monitor-brand-name }
+auto-scan = Wedi'u sganio'n awtomatig heddiw
+
+monitor-emails-tooltip =
+    .title = Gweld cyfeiriadau e-bost wedi'u monitro ar { -monitor-brand-short-name }
+monitor-breaches-tooltip =
+    .title = Gweld tor-data hysbys ar { -monitor-brand-short-name }
+monitor-passwords-tooltip =
+    .title = Gweld cyfrineiriau wedi'u datgelu ar { -monitor-brand-short-name }
+
+# This string is displayed after a large numeral that indicates the total number
+# of email addresses being monitored. Don’t add $count to
+# your localization, because it would result in the number showing twice.
+info-monitored-emails =
+    { $count ->
+        [zero] Cyfeiriadau e-bost yn cael eu monitro
+        [one] Cyfeiriad e-bost yn cael ei fonitro
+        [two] Gyfeiriad e-bost yn cael eu monitro
+        [few] Cyfeiriad e-bost yn cael eu monitro
+        [many] Chyfeiriad e-bost yn cael eu monitro
+       *[other] Cyfeiriad e-bost yn cael eu monitro
+    }
+
+# This string is displayed after a large numeral that indicates the total number
+# of known data breaches. Don’t add $count to
+# your localization, because it would result in the number showing twice.
+info-known-breaches-found =
+    { $count ->
+        [zero] Tor-data hysbys wedi amlygu eich manylion
+        [one] Tor-data hysbys wedi amlygu eich manylion
+        [two] Dor-data hysbys wedi amlygu eich manylion
+        [few] Tor-data hysbys wedi amlygu eich manylion
+        [many] Thor-data hysbys wedi amlygu eich manylion
+       *[other] Tor-data hysbys wedi amlygu eich manylion
+    }
+
+# This string is displayed after a large numeral that indicates the total number
+# of known data breaches that are marked as resolved by the user. Don’t add $count
+# to your localization, because it would result in the number showing twice.
+info-known-breaches-resolved =
+    { $count ->
+        [zero] Tor-data hysbys wedi'u nodi fel wedi'u datrys
+        [one] Tor-data hysbys wedi'i nodi fel wedi'i ddatrys
+        [two] Dor-data hysbys wedi'u nodi fel wedi'u datrys
+        [few] Tor-data hysbys wedi'u nodi fel wedi'u datrys
+        [many] Thor-data hysbys wedi'u nodi fel wedi'u datrys
+       *[other] Tor-data hysbys wedi'u nodi fel wedi'u datrys
+    }
+
+# This string is displayed after a large numeral that indicates the total number
+# of exposed passwords. Don’t add $count to
+# your localization, because it would result in the number showing twice.
+info-exposed-passwords-found =
+    { $count ->
+        [zero] Cyfrineiriau wedi'u hamlygu ym mhob tor-data
+        [one] Cyfrinair wedi'i amlygu ym mhob tor-data
+        [two] Cyfrinair wedi'u hamlygu ym mhob tor-data
+        [few] Cyfrinair wedi'u hamlygu ym mhob tor-data
+        [many] Chyfrinair wedi'u hamlygu ym mhob tor-data
+       *[other] Cyfrinair wedi'u hamlygu ym mhob tor-data
+    }
+
+# This string is displayed after a large numeral that indicates the total number
+# of exposed passwords that are marked as resolved by the user. Don’t add $count
+# to your localization, because it would result in the number showing twice.
+info-exposed-passwords-resolved =
+    { $count ->
+        [zero] Cyfrineiriau wedi'u hamlygu mewn tor-data heb eu datrys
+        [one] Cyfrinair wedi'i amlygu mewn tor-data heb ei ddatrys
+        [two] Gyfrinair wedi'u hamlygu mewn tor-data heb eu datrys
+        [few] Cyfrinair wedi'u hamlygu mewn tor-data heb eu datrys
+        [many] Chyfrinair wedi'u hamlygu mewn tor-data heb eu datrys
+       *[other] Cyfrinair wedi'u hamlygu mewn tor-data heb eu datrys
+    }
+
+monitor-no-breaches-title = Newyddion da!
+monitor-no-breaches-description = Nid oes gennych unrhyw dor-data hysbys. Os bydd hynny'n newid, byddwn yn rhoi gwybod i chi.
+monitor-view-report-link = Gweld yr Adroddiad
+    .title = Datrys tor-data ar { -monitor-brand-short-name }
+monitor-breaches-unresolved-title = Datrys eich tor-data
+monitor-breaches-unresolved-description = Ar ôl adolygu manylion tor-data a chymryd camau i ddiogelu eich manylion, gallwch nodi fod eich tor-data wedi'u datrys.
+monitor-manage-breaches-link = Rheoli Tor-data
+    .title = Rheoli tor-data ar { -monitor-brand-short-name }
+monitor-breaches-resolved-title = Da! Rydych wedi datrys pob achos o dor-data hysbys.
+monitor-breaches-resolved-description = Os bydd eich e-bost yn ymddangos mewn unrhyw dor-data newydd, byddwn yn rhoi gwybod i chi.
+
+# Variables:
+# $numBreachesResolved (Number) - Number of breaches marked as resolved by the user on Monitor.
+# $numBreaches (Number) - Number of breaches in which a user's data was involved, detected by Monitor.
+monitor-partial-breaches-title =
+    { $numBreaches ->
+        [zero] { $numBreachesResolved } allan o { $numBreaches } tor-data wedi'u marcio fel wedi'u datrys
+        [one] { $numBreachesResolved } allan o { $numBreaches } tor-data wedi'i farcio fel wedi'i ddatrys
+        [two] { $numBreachesResolved } allan o { $numBreaches } tor-data wedi'u marcio fel wedi'u datrys
+        [few] { $numBreachesResolved } allan o { $numBreaches } tor-data wedi'u marcio fel wedi'u datrys
+        [many] { $numBreachesResolved } allan o { $numBreaches } tor-data wedi'u marcio fel wedi'u datrys
+       *[other] { $numBreachesResolved } allan o { $numBreaches } tor-data wedi'u marcio fel wedi'u datrys
+    }
+
+# Variables:
+# $percentageResolved (Number) - Percentage of breaches marked as resolved by a user on Monitor.
+monitor-partial-breaches-percentage = { $percentageResolved }% wedi'u cwblhau
+
+monitor-partial-breaches-motivation-title-start = Dechrau da!
+monitor-partial-breaches-motivation-title-middle = Daliwch ati!
+monitor-partial-breaches-motivation-title-end = Bron wedi ei wneud! Daliwch ati.
+monitor-partial-breaches-motivation-description = Datryswch weddill eich tor-data ar { -monitor-brand-short-name }
+monitor-resolve-breaches-link = Datrys Tor-data
+    .title = Datrys tor-data ar { -monitor-brand-short-name }
+
+## The title attribute is used to display the type of protection.
+## The aria-label is spoken by screen readers to make the visual graph accessible to blind users.
+##
+## Variables:
+##   $count (Number) - Number of specific trackers
+##   $percentage (Number) - Percentage this type of tracker contributes to the whole graph
+
+bar-tooltip-social =
+    .title = Tracwyr Cyfryngau Cymdeithasol
+    .aria-label =
+        { $count ->
+            [zero] { $count } tracwyr cyfryngau cymdeithasol ({ $percentage }%)
+            [one] { $count } traciwr cyfryngau cymdeithasol ({ $percentage }%)
+            [two] { $count } draciwr cyfryngau cymdeithasol ({ $percentage }%)
+            [few] { $count } traciwr cyfryngau cymdeithasol ({ $percentage }%)
+            [many] { $count } traciwr cyfryngau cymdeithasol ({ $percentage }%)
+           *[other] { $count } traciwr cyfryngau cymdeithasol ({ $percentage }%)
+        }
+bar-tooltip-cookie =
+    .title = Cwcis Tracio Traws-Gwefan
+    .aria-label =
+        { $count ->
+            [zero] { $count } cwcis tracio traws-gwefan ({ $percentage }%)
+            [one] { $count } cwci tracio traws-gwefan ({ $percentage }%)
+            [two] { $count } gwci tracio traws-gwefan ({ $percentage }%)
+            [few] { $count } cwci tracio traws-gwefan ({ $percentage }%)
+            [many] { $count } cwci tracio traws-gwefan ({ $percentage }%)
+           *[other] { $count } cwci tracio traws-gwefan ({ $percentage }%)
+        }
+bar-tooltip-tracker =
+    .title = Cynnwys Tracio
+    .aria-label =
+        { $count ->
+            [zero] { $count } cynnwys tracio ({ $percentage }%)
+            [one] { $count } cynnwys tracio ({ $percentage }%)
+            [two] { $count } cynnwys tracio ({ $percentage }%)
+            [few] { $count } cynnwys tracio ({ $percentage }%)
+            [many] { $count } cynnwys tracio ({ $percentage }%)
+           *[other] { $count } cynnwys tracio ({ $percentage }%)
+        }
+bar-tooltip-fingerprinter =
+    .title = Bysbrintwyr
+    .aria-label =
+        { $count ->
+            [zero] { $count } bysbrintwyr ({ $percentage }%)
+            [one] { $count } bysbrintwyr ({ $percentage }%)
+            [two] { $count } bysbrintwyr ({ $percentage }%)
+            [few] { $count } bysbrintwyr ({ $percentage }%)
+            [many] { $count } bysbrintwyr ({ $percentage }%)
+           *[other] { $count } bysbrintwyr ({ $percentage }%)
+        }
+bar-tooltip-cryptominer =
+    .title = Cryptogloddwyr
+    .aria-label =
+        { $count ->
+            [zero] { $count } cryptogloddwyr ({ $percentage }%)
+            [one] { $count } cryptogloddwyr ({ $percentage }%)
+            [two] { $count } cryptogloddwyr ({ $percentage }%)
+            [few] { $count } cryptogloddwyr ({ $percentage }%)
+            [many] { $count } cryptogloddwyr ({ $percentage }%)
+           *[other] { $count } cryptogloddwyr ({ $percentage }%)
+        }
diff --git a/l10n-cy/browser/browser/protectionsPanel.ftl b/l10n-cy/browser/browser/protectionsPanel.ftl
new file mode 100644
index 0000000000..fd580f51e6
--- /dev/null
+++ b/l10n-cy/browser/browser/protectionsPanel.ftl
@@ -0,0 +1,113 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+protections-panel-sendreportview-error = Bu gwall wrth anfon yr adroddiad. Rhowch gynnig arall arni'n hwyrach.
+
+# A link shown when ETP is disabled for a site. Opens the breakage report subview when clicked.
+protections-panel-sitefixedsendreport-label = Gwefan wedi'i thrwsio? Anfon adroddiad
+
+## These strings are used to define the different levels of
+## Enhanced Tracking Protection.
+
+protections-popup-footer-protection-label-strict = Llym
+    .label = Llym
+protections-popup-footer-protection-label-custom = Cyfaddasu
+    .label = Cyfaddasu
+protections-popup-footer-protection-label-standard = Safonol
+    .label = Safonol
+
+##
+
+# The text a screen reader speaks when focused on the info button.
+protections-panel-etp-more-info =
+    .aria-label = Rhagor o wybodaeth am Ddiogelwch Rhag Tracio Uwch
+
+protections-panel-etp-on-header = Mae Diogelwch Uwch Rhag Tracio YMLAEN ar y wefan hon
+protections-panel-etp-off-header = Mae Diogelwch Uwch Rhag Tracio I FFWRDD ar y wefan hon
+
+# The link to be clicked to open the sub-panel view
+protections-panel-site-not-working = Gwefan ddim yn gweithio?
+
+# The heading/title of the sub-panel view
+protections-panel-site-not-working-view =
+    .title = Gwefan Ddim yn Gweithio?
+
+## The "Allowed" header also includes a "Why?" link that, when hovered, shows
+## a tooltip explaining why these items were not blocked in the page.
+
+protections-panel-not-blocking-why-label = Pam?
+protections-panel-not-blocking-why-etp-on-tooltip = Gallai rhwystro'r rhain dorri elfennau o rai gwefannau. Heb dracwyr, efallai na fydd rhai botymau, ffurflenni a meysydd mewngofnodi'n gweithio.
+protections-panel-not-blocking-why-etp-off-tooltip = Mae'r holl dracwyr ar y wefan hon wedi'u llwytho gan fod diogelu wedi'i ddiffodd.
+
+##
+
+protections-panel-no-trackers-found = Dim tracwyr hysbys i { -brand-short-name } wedi eu canfod ar y dudalen hon.
+
+protections-panel-content-blocking-tracking-protection = Cynnwys Tracio
+
+protections-panel-content-blocking-socialblock = Tracwyr Cyfryngau Cymdeithasol
+protections-panel-content-blocking-cryptominers-label = Cryptogloddwyr
+protections-panel-content-blocking-fingerprinters-label = Bysbrintwyr
+
+## In the protections panel, Content Blocking category items are in three sections:
+##   "Blocked" for categories being blocked in the current page,
+##   "Allowed" for categories detected but not blocked in the current page, and
+##   "None Detected" for categories not detected in the current page.
+##   These strings are used in the header labels of each of these sections.
+
+protections-panel-blocking-label = Rhwystrwyd
+protections-panel-not-blocking-label = Caniatawyd
+protections-panel-not-found-label = Heb Ganfod Dim
+
+##
+
+protections-panel-settings-label = Gosodiadau Diogelu
+# This should match the "appmenuitem-protection-dashboard-title" string in browser/appmenu.ftl.
+protections-panel-protectionsdashboard-label = Bwrdd Gwaith Diogelwch
+
+## In the Site Not Working? view, we suggest turning off protections if
+## the user is experiencing issues with any of a variety of functionality.
+
+# The header of the list
+protections-panel-site-not-working-view-header = Diffoddwch ddiogelu os rydych yn cael problemau gyda:
+
+# The list items, shown in a <ul>
+protections-panel-site-not-working-view-issue-list-login-fields = Meysydd mewngofnodi
+protections-panel-site-not-working-view-issue-list-forms = Ffurflenni
+protections-panel-site-not-working-view-issue-list-payments = Taliadau
+protections-panel-site-not-working-view-issue-list-comments = Sylwadau
+protections-panel-site-not-working-view-issue-list-videos = Fideos
+
+protections-panel-site-not-working-view-send-report = Anfon adroddiad
+
+##
+
+protections-panel-cross-site-tracking-cookies = Mae'r cwcis hyn yn eich dilyn o wefan i wefan i gasglu data am yr hyn rydych chi'n ei wneud ar-lein. Maen nhw'n cael eu gosod gan drydydd partïon fel hysbysebwyr a chwmnïau dadansoddol.
+protections-panel-cryptominers = Mae cryptogloddwyr yn defnyddio pŵer cyfrifiadurol eich system i gloddio arian digidol. Mae sgriptiau cryptogloddio yn gwagio eich batri, arafu eich cyfrifiadur, a gall gynyddu eich bil trydan.
+protections-panel-fingerprinters = Mae bysbrintwyr yn casglu gosodiadau o'ch porwr a'ch cyfrifiadur i greu proffil ohonoch. Gan ddefnyddio'r olion bys digidol hwn, mae nhw'n gallu'ch tracio ar draws gwahanol wefannau.
+protections-panel-tracking-content = Gall gwefannau lwytho hysbysebion allanol, fideos a chynnwys eraill sy'n cynnwys cod tracio. Gall rhwystro cynnwys tracio helpu gwefannau i lwytho'n gynt, ond efallai na fydd rhai botymau, ffurflenni a meysydd mewngofnodi'n gweithio.
+protections-panel-social-media-trackers = Mae rhwydweithiau cymdeithasol yn gosod tracwyr ar wefannau eraill i ddilyn yr hyn rydych chi'n ei wneud, ei weld, a'i wylio ar-lein. Mae hyn yn caniatáu i gwmnïau cyfryngau cymdeithasol ddysgu mwy amdanoch chi y tu hwnt i'r hyn rydych chi'n ei rannu ar eich proffiliau cyfryngau cymdeithasol.
+
+protections-panel-description-shim-allowed = Mae rhai tracwyr sydd wedi'u marcio isod wedi cael eu dad-rwystr'n rhannol ar y dudalen hon oherwydd i chi ryngweithio â nhw.
+protections-panel-description-shim-allowed-learn-more = Dysgu rhagor
+protections-panel-shim-allowed-indicator =
+    .tooltiptext = Traciwr wedi'i rhannol ddad-rwystro
+
+protections-panel-content-blocking-manage-settings =
+    .label = Rheoli Gosodiadau Diogelu
+    .accesskey = R
+
+protections-panel-content-blocking-breakage-report-view =
+    .title = Adrodd ar Wefan wedi Torri
+protections-panel-content-blocking-breakage-report-view-description = Gall rhwystro cynnwys achosi problemau gyda rai gwefannau. Pan fyddwch yn cyflwyno adroddiad ar broblemau, byddwch yn helpu gwneud { -brand-short-name } yn well i bawb. (Bydd hyn yn anfon yr URL yn ogystal â gwybodaeth am osodiadau eich porwr i Mozilla. <label data-l10n-name="learn-more">Dysgu rhagor</label>
+protections-panel-content-blocking-breakage-report-view-collection-url = URL
+protections-panel-content-blocking-breakage-report-view-collection-url-label =
+    .aria-label = URL
+protections-panel-content-blocking-breakage-report-view-collection-comments = Dewisol: Disgrifiwch y broblem
+protections-panel-content-blocking-breakage-report-view-collection-comments-label =
+    .aria-label = Dewisol: Disgrifiwch y broblem
+protections-panel-content-blocking-breakage-report-view-cancel =
+    .label = Diddymu
+protections-panel-content-blocking-breakage-report-view-send-report =
+    .label = Anfon Adroddiad
diff --git a/l10n-cy/browser/browser/safeMode.ftl b/l10n-cy/browser/browser/safeMode.ftl
new file mode 100644
index 0000000000..7c5fc13aa6
--- /dev/null
+++ b/l10n-cy/browser/browser/safeMode.ftl
@@ -0,0 +1,15 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+troubleshoot-mode-window =
+    .title = Agor { -brand-short-name } yn y Modd Datrys Problemau?
+    .style = max-width: 400px
+start-troubleshoot-mode =
+    .label = Agor
+refresh-profile =
+    .label = Adnewyddu { -brand-short-name }
+troubleshoot-mode-description = Defnyddiwch y modd arbennig hwn o { -brand-short-name } i ddatrys materion. Bydd eich estyniadau a'ch cyfaddasiadau yn cael eu hanalluogi anabl dros dro.
+skip-troubleshoot-refresh-profile = Gallwch hepgor datrys problemau a cheisio adnewyddu { -brand-short-name }, yn lle hynny.
+# Shown on the safe mode dialog after multiple startup crashes.
+auto-safe-mode-description = Caeodd { -brand-short-name } yn annisgwyl wrth gychwyn. Efallai fod hyn o ganlyniad i ychwanegyn neu anhawster arall. Mae modd ceisio datrys y broblem o fewn y Modd Diogel.
diff --git a/l10n-cy/browser/browser/safebrowsing/blockedSite.ftl b/l10n-cy/browser/browser/safebrowsing/blockedSite.ftl
new file mode 100644
index 0000000000..c81ee44e41
--- /dev/null
+++ b/l10n-cy/browser/browser/safebrowsing/blockedSite.ftl
@@ -0,0 +1,30 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+safeb-blocked-phishing-page-title = Gwefan twyllodrus o'ch blaen
+safeb-blocked-malware-page-title = Gall mynd i'r wefan hon wneud drwg i'ch cyfrifiadur
+safeb-blocked-unwanted-page-title = Gall fod y wefan o'ch blaen yn cynnwys rhaglenni niweidiol
+safeb-blocked-harmful-page-title = Gall fod y wefan yn cynnwys drwgwar
+safeb-blocked-phishing-page-short-desc = Mae { -brand-short-name } wedi rhwystro'r dudalen hon gan y gallai geisio eich twyllo i wneud rhywbeth peryglus fel gosod meddalwedd neu ddatgelu manylion personol fel cyfrineiriau neu gardiau credyd.
+safeb-blocked-malware-page-short-desc = Mae { -brand-short-name } wedi atal y dudalen hon gan y gall geisio gosod meddalwedd drwg er mwyn drwyn neu ddileu gwybodaeth bersonol ar eich cyfrifiadur.
+safeb-blocked-unwanted-page-short-desc = Mae { -brand-short-name } wedi rhwystro'r dudalen hon gan y gall geisio eich twyllo i osod rhaglenni gall fod yn niweidiol i'ch profiad pori (e.e. drwy newid eich tudalen cartref neu ddangos hysbysebion ychwanegol ar wefannau rydych yn ymweld â nhw).
+safeb-blocked-harmful-page-short-desc = Mae { -brand-short-name } wedi rhwystro'r dudalen hon gan y gall geisio gosod apiau peryglus sy'n dwyn neu ddileu eich manylion (e.e., lluniau, cyfrineiriau, negeseuon a chardiau credyd).
+safeb-palm-advisory-desc = Cyngor yn cael ei ddarparu gan <a data-l10n-name='advisory_provider'>{ $advisoryname }</a>.
+safeb-palm-accept-label = Nôl
+safeb-palm-see-details-label = Gweld manylion
+safeb-blocked-phishing-page-error-desc-override = Mae <span data-l10n-name='sitename'>{ $sitename }</span> yn hysbys <a data-l10n-name='error_desc_link'>fel gwefan twyllodrus</a>. Gallwch <a data-l10n-name='report_detection'>adrodd ar anhawster canfod</a> neu <a data-l10n-name='ignore_warning_link'>anwybyddu'r perygl</a> a mynd i'r wefan anniogel hon.
+safeb-blocked-phishing-page-error-desc-no-override = Mae <span data-l10n-name='sitename'>{ $sitename }</span> yn hysbys <a data-l10n-name='error_desc_link'>fel gwefan twyllodrus</a>. Gallwch <a data-l10n-name='report_detection'>adrodd ar anhawster canfod</a>.
+safeb-blocked-phishing-page-learn-more = Mae rhagor o wybodaeth am wefannau twyllodrus a physgota yn <a data-l10n-name='learn_more_link'>www.antiphishing.org</a>. A Diogelwch rhag Pysgota a Drwgwar { -brand-short-name } yn <a data-l10n-name='firefox_support'>support.mozilla.org</a>.
+safeb-blocked-malware-page-error-desc-override-sumo = Mae <span data-l10n-name='sitename'>{ $sitename }</span> y hysbys <a data-l10n-name='error_desc_link'>fel gwefan sy'n cynnwys meddalwedd maleisus</a>. Gallwch <a data-l10n-name='ignore_warning_link'>anwybyddu'r perygl</a> a mynd i'r wefan anniogel hon.
+safeb-blocked-malware-page-error-desc-no-override-sumo = Mae <span data-l10n-name='sitename'>{ $sitename }</span> yn hysbys <a data-l10n-name='error_desc_link'>fel gwefan sy'n cynnwys meddalwedd maleisus</a>.
+safeb-blocked-malware-page-learn-more-sumo = Dysgu rhagor am Ddiogelwch rhag Pysgota a Drwgwar { -brand-short-name } yn <a data-l10n-name='firefox_support'> support.mozilla.org </a>.
+safeb-blocked-unwanted-page-error-desc-override = Mae <span data-l10n-name='sitename'>{ $sitename }</span> y hysbys <a data-l10n-name='error_desc_link'>fel gwefan sy'n cynnwys meddalwedd niweidiol</a>. Gallwch <a data-l10n-name='ignore_warning_link'>anwybyddu'r perygl</a> a mynd i'r wefan anniogel hon.
+safeb-blocked-unwanted-page-error-desc-no-override = Mae <span data-l10n-name='sitename'>{ $sitename }</span> yn hysbys <a data-l10n-name='error_desc_link'>fel gwefan sy'n cynnwys meddalwedd niweidiol</a>.
+safeb-blocked-unwanted-page-learn-more = Mae rhagor o wybodaeth am feddalwedd niweidiol a digroeso yn <a data-l10n-name='learn_more_link'>Polisi Meddalwedd Digroeso</a>. A Diogelwch rhag Pysgota a Drwgwar { -brand-short-name } yn <a data-l10n-name='firefox_support'>support.mozilla.org</a>.
+safeb-blocked-harmful-page-error-desc-override = Mae <span data-l10n-name='sitename'>{ $sitename }</span> yn hysbys <a data-l10n-name='error_desc_link'>fel gwefan sy'n cynnwys rhaglen sydd o bosib yn niweidiol</a>. Gallwch <a data-l10n-name='ignore_warning_link'>anwybyddu'r perygl</a> a mynd i'r wefan anniogel hon.
+safeb-blocked-harmful-page-error-desc-no-override = Mae <span data-l10n-name='sitename'>{ $sitename }</span> yn hysbys <a data-l10n-name='error_desc_link'>fel wefan sy'n cynnwys rhaglen sydd o bosib yn niweidiol</a>.
+safeb-blocked-harmful-page-learn-more = Mae rhagor o wybodaeth am Ddiogelwch Rhag Pysgota a Drwgwar { -brand-short-name } yn <a data-l10n-name='firefox_support'>support.mozilla.org</a>.
+safeb-palm-notdeceptive =
+    .label = Nid yw hon yn wefan twyllodrus…
+    .accesskey = t
diff --git a/l10n-cy/browser/browser/sanitize.ftl b/l10n-cy/browser/browser/sanitize.ftl
new file mode 100644
index 0000000000..c33f9ed2f1
--- /dev/null
+++ b/l10n-cy/browser/browser/sanitize.ftl
@@ -0,0 +1,114 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+sanitize-prefs =
+    .title = Gosodiadau Clirio Hanes
+    .style = width: 34em
+
+sanitize-prefs2 =
+    .title = Gosodiadau Clirio Hanes
+    .style = min-width: 34em
+
+sanitize-prefs-style =
+    .style = width: 17em
+
+dialog-title =
+    .title = Clirio'r Hanes Diweddar
+    .style = width: 34em
+
+# When "Time range to clear" is set to "Everything", this message is used for the
+# title instead of dialog-title.
+dialog-title-everything =
+    .title = Clirio'r Holl Hanes
+    .style = width: 34em
+
+clear-data-settings-label = Pan fyddai'n gadael { -brand-short-name } dylai glirio popeth yn awtomatig
+
+## clear-time-duration-prefix is followed by a dropdown list, with
+## values localized using clear-time-duration-value-* messages.
+## clear-time-duration-suffix is left empty in English, but can be
+## used in other languages to change the structure of the message.
+##
+## This results in English:
+## Time range to clear: (Last Hour, Today, etc.)
+
+clear-time-duration-prefix =
+    .value = Cyfnod i'w glirio:{ " " }
+    .accesskey = C
+
+clear-time-duration-value-last-hour =
+    .label = Awr Diwethaf
+
+clear-time-duration-value-last-2-hours =
+    .label = Dwy Awr Diwethaf
+
+clear-time-duration-value-last-4-hours =
+    .label = Pedair Awr Diwethaf
+
+clear-time-duration-value-today =
+    .label = Heddiw
+
+clear-time-duration-value-everything =
+    .label = Popeth
+
+clear-time-duration-suffix =
+    .value = { "" }
+
+## These strings are used as section comments and checkboxes
+## to select the items to remove
+
+history-section-label = Hanes
+
+item-history-and-downloads =
+    .label = Hanes Pori a Llwytho i Lawr
+    .accesskey = H
+
+item-cookies =
+    .label = Cwcis
+    .accesskey = w
+
+item-active-logins =
+    .label = Mewngofnodion Gweithredol
+    .accesskey = M
+
+item-cache =
+    .label = Storfa Dros Dro
+    .accesskey = S
+
+item-form-search-history =
+    .label = Hanes Ffurflenni a Chwilio
+    .accesskey = F
+
+data-section-label = Data
+
+item-site-settings =
+    .label = Gosodiadau gwefan
+    .accesskey = G
+
+item-offline-apps =
+    .label = Data Gwefan All-lein
+    .accesskey = D
+
+sanitize-everything-undo-warning = Nid oes modd dadwneud y weithred.
+
+window-close =
+    .key = w
+
+sanitize-button-ok =
+    .label = Clirio Nawr
+
+# The label for the default button between the user clicking it and the window
+# closing.  Indicates the items are being cleared.
+sanitize-button-clearing =
+    .label = Clirio
+
+# Warning that appears when "Time range to clear" is set to "Everything" in Clear
+# Recent History dialog, provided that the user has not modified the default set
+# of history items to clear.
+sanitize-everything-warning = Bydd yr holl hanes yn cael ei glirio.
+
+# Warning that appears when "Time range to clear" is set to "Everything" in Clear
+# Recent History dialog, provided that the user has modified the default set of
+# history items to clear.
+sanitize-selected-warning = Bydd yr holl eitemau a ddewiswyd yn cael eu clirio.
diff --git a/l10n-cy/browser/browser/screenshots.ftl b/l10n-cy/browser/browser/screenshots.ftl
new file mode 100644
index 0000000000..356960dcbc
--- /dev/null
+++ b/l10n-cy/browser/browser/screenshots.ftl
@@ -0,0 +1,48 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+screenshot-toolbarbutton =
+    .label = Ciplun
+    .tooltiptext = Cymryd ciplun
+screenshot-shortcut =
+    .key = S
+screenshots-instructions = Llusgwch neu glicio ar y dudalen i ddewis adran. Pwyso ESC i ddiddymu.
+screenshots-cancel-button = Diddymu
+screenshots-save-visible-button = Cadw'r gweladwy
+screenshots-save-page-button = Cadw tudalen lawn
+screenshots-download-button = Llwytho i Lawr
+screenshots-download-button-tooltip = Llwytho i lawr llun sgrin
+screenshots-copy-button = Copïo
+screenshots-copy-button-tooltip = Copïo llun sgrin i'r clipfwrdd
+screenshots-download-button-title =
+    .title = Llwytho i lawr llun sgrin
+screenshots-copy-button-title =
+    .title = Copïo llun sgrin i'r clipfwrdd
+screenshots-cancel-button-title =
+    .title = Diddymu
+screenshots-retry-button-title =
+    .title = Cymryd sgrin llun eto
+screenshots-meta-key =
+    { PLATFORM() ->
+        [macos] ⌘
+       *[other] Ctrl
+    }
+screenshots-notification-link-copied-title = Dolen wedi ei Chadw
+screenshots-notification-link-copied-details = Mae'r ddolen i'ch llun wedi ei gopïo i'r clipfwrdd. Pwyswch { screenshots-meta-key }-V i'w ludo.
+screenshots-notification-image-copied-title = Copïwyd y Llun
+screenshots-notification-image-copied-details = Mae eich llun wedi ei gopïo i'r clipfwrdd. Pwyswch { screenshots-meta-key }-V i'w ludo.
+screenshots-request-error-title = Ddim yn gweithio.
+screenshots-request-error-details = Ymddiheuriadau! Nid oedd modd cadw eich llun. Ceisiwch eto'n hwyrach.
+screenshots-connection-error-title = Nid oes modd i ni gysylltu a'ch lluniau sgrin.
+screenshots-connection-error-details = Gwiriwch eich cysylltiad Rhyngrwyd. Os ydych yn gallu cysylltu â'r Rhyngrwyd, efallai bod anhawster dros dro gyda gwasanaeth lluniau sgrin, { -screenshots-brand-name }.
+screenshots-login-error-details = Nid oedd modd i ni gadw eich llun gan fod yna anhawster gyda gwasanaeth { -screenshots-brand-name }. Ceisiwch eto'n hwyrach.
+screenshots-unshootable-page-error-title = Nid oes modd tynnu llun sgrin o'r dudalen.
+screenshots-unshootable-page-error-details = Nid yw hwn yn dudalen Gwe safonol, felly does dim modd tynnu llun sgrin ohono.
+screenshots-empty-selection-error-title = Mae eich dewis yn rhy fach
+screenshots-private-window-error-title = Mae { -screenshots-brand-name } wedi ei analluogi yn y Modd Pori Preifat
+screenshots-private-window-error-details = Ymddiheuriadau am yr anhwylustod. Rydym yn gweithio ar y nodwedd hwn ar gyfer fersiynau'r dyfodol.
+screenshots-generic-error-title = Www! Mae { -screenshots-brand-name } wedi mynd yn hurt.
+screenshots-generic-error-details = Nid ydym yn gwybod beth sydd wedi ddigwydd. Ceisiwch eto neu dynnu llun o dudalen wahanol?
+screenshots-too-large-error-title = Cafodd eich llun sgrin ei docio am ei fod yn rhy fawr
+screenshots-too-large-error-details = Ceisiwch ddewis ardal sy'n llai na 32,700 picsel ar ei ochr hiraf neu gyfanswm arwynebedd o 124,900,000 picsel.
diff --git a/l10n-cy/browser/browser/screenshotsOverlay.ftl b/l10n-cy/browser/browser/screenshotsOverlay.ftl
new file mode 100644
index 0000000000..6250f03b0e
--- /dev/null
+++ b/l10n-cy/browser/browser/screenshotsOverlay.ftl
@@ -0,0 +1,8 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+screenshots-overlay-cancel-button = Diddymu
+screenshots-overlay-instructions = Llusgwch neu glicio ar y dudalen i ddewis ardal. Pwyso ESC i ddiddymu.
+screenshots-overlay-download-button = Llwytho i Lawr
+screenshots-overlay-copy-button = Copïo
diff --git a/l10n-cy/browser/browser/search.ftl b/l10n-cy/browser/browser/search.ftl
new file mode 100644
index 0000000000..3909989215
--- /dev/null
+++ b/l10n-cy/browser/browser/search.ftl
@@ -0,0 +1,38 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+## These strings are used for errors when installing OpenSearch engines, e.g.
+## via "Add Search Engine" on the address bar or search bar.
+## Variables
+## $location-url (String) - the URL of the OpenSearch engine that was attempted to be installed.
+
+opensearch-error-duplicate-title = Gwall Gosod
+opensearch-error-duplicate-desc = Methodd { -brand-short-name } â gosod yr ategyn chwilio o "{ $location-url }" gan fod peiriant chwilio sydd â'r un enw yn bodoli'n barod.
+
+opensearch-error-format-title = Fformat Annilys
+opensearch-error-format-desc = Nid yw { -brand-short-name } yn gallu gosod y peiriant chwilio o { $location-url }
+
+opensearch-error-download-title = Gwall llwytho i lawr
+opensearch-error-download-desc = Methodd { -brand-short-name } â llwytho i lawr yr ategyn chwilio o: { $location-url }
+
+##
+
+searchbar-submit =
+    .tooltiptext = Cyflwyno'r chwilio
+
+# This string is displayed in the search box when the input field is empty
+searchbar-input =
+    .placeholder = Chwilio
+
+searchbar-icon =
+    .tooltiptext = Chwilio
+
+## Infobar shown when search engine is removed and replaced.
+## Variables
+## $oldEngine (String) - the search engine to be removed.
+## $newEngine (String) - the search engine to replace the removed search engine.
+
+removed-search-engine-message = <strong>Mae eich peiriant chwilio rhagosodedig wedi'i newid.</strong> Nid yw { $oldEngine } ar gael bellach fel peiriant chwilio rhagosodedig yn { -brand-short-name }. { $newEngine } yw eich peiriant chwilio rhagosodedig bellach. I newid i beiriant chwilio rhagosodedig arall, ewch i'r gosodiadau. <label data-l10n-name="remove-search-engine-article">Dysgu rhagor</label>
+remove-search-engine-button = Iawn
diff --git a/l10n-cy/browser/browser/setDesktopBackground.ftl b/l10n-cy/browser/browser/setDesktopBackground.ftl
new file mode 100644
index 0000000000..dfcc07da23
--- /dev/null
+++ b/l10n-cy/browser/browser/setDesktopBackground.ftl
@@ -0,0 +1,40 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+set-desktop-background-window =
+    .title = Gosod Cefndir Bwrdd Gwaith
+
+set-desktop-background-accept =
+    .label = Gosod Cefndir Bwrdd Gwaith
+
+open-desktop-prefs =
+    .label = Dewisiadau'r Bwrdd Gwaith Agored
+
+set-background-preview-unavailable = Dim rhagolwg ar gael
+
+# This refers to the wallpaper "spanning" multiple monitors when the
+# user has more than one. Only some of the entire image will be on
+# each monitor. This should ideally match the wording in Windows' own
+# Desktop Background settings page.
+set-background-span =
+    .label = Ymestyn
+
+set-background-color = Lliw:
+
+set-background-position = Safle:
+
+set-background-tile =
+    .label = Teilio
+
+set-background-center =
+    .label = Canol
+
+set-background-stretch =
+    .label = Estyn
+
+set-background-fill =
+    .label = Llanw
+
+set-background-fit =
+    .label = Ffitio
diff --git a/l10n-cy/browser/browser/sidebarMenu.ftl b/l10n-cy/browser/browser/sidebarMenu.ftl
new file mode 100644
index 0000000000..8c04772a4d
--- /dev/null
+++ b/l10n-cy/browser/browser/sidebarMenu.ftl
@@ -0,0 +1,18 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+sidebar-menu-bookmarks =
+    .label = Nodau Tudalen
+
+sidebar-menu-history =
+    .label = Hanes
+
+sidebar-menu-synced-tabs =
+    .label = Tabiau wedi'u Cydweddu
+
+sidebar-menu-close =
+    .label = Cau'r Bar Ochr
+
+sidebar-close-button =
+    .tooltiptext = Cau'r bar ochr
diff --git a/l10n-cy/browser/browser/sitePermissions.ftl b/l10n-cy/browser/browser/sitePermissions.ftl
new file mode 100644
index 0000000000..7e1e20325d
--- /dev/null
+++ b/l10n-cy/browser/browser/sitePermissions.ftl
@@ -0,0 +1,16 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# This string is used to display the option to open blocked popup(s) in site permission management panels.
+# Variables:
+#   $count (String) - Number of blocked pop-ups
+site-permissions-open-blocked-popups =
+    { $count ->
+        [zero] Agor { $count } llamlenni wedi'u rhwystro…
+        [one] Agor { $count } llamlen wedi'i rwystro…
+        [two] Agor { $count } llamlen wedi'u rhwystro…
+        [few] Agor { $count } llamlen wedi'u rhwystro…
+        [many] Agor { $count } llamlen wedi'u rhwystro…
+       *[other] Agor { $count } llamlen wedi'u rhwystro…
+    }
diff --git a/l10n-cy/browser/browser/spotlight.ftl b/l10n-cy/browser/browser/spotlight.ftl
new file mode 100644
index 0000000000..67c8920eaf
--- /dev/null
+++ b/l10n-cy/browser/browser/spotlight.ftl
@@ -0,0 +1,22 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# Dialog close button
+spotlight-dialog-close-button =
+    .title = Cau
+    .aria-label = Cau
+
+## Mobile download button strings
+
+spotlight-android-marketplace-button =
+    .title = Mae ar gael yn Google Play
+spotlight-ios-marketplace-button =
+    .title = Llwythwch i lawr o'r App Store
+
+## Firefox Focus promo message strings
+
+spotlight-focus-promo-title = Cael { -focus-brand-name }
+spotlight-focus-promo-subtitle = Sganiwch y cod QR i'w lwytho i lawr
+spotlight-focus-promo-qr-code =
+    .alt = Sganiwch y cod QR i gael { -focus-brand-name }
diff --git a/l10n-cy/browser/browser/sync.ftl b/l10n-cy/browser/browser/sync.ftl
new file mode 100644
index 0000000000..a660b73d81
--- /dev/null
+++ b/l10n-cy/browser/browser/sync.ftl
@@ -0,0 +1,33 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+fxa-toolbar-sync-syncing2 = Cydweddu…
+
+sync-disconnect-dialog-title2 = Datgysylltu?
+sync-disconnect-dialog-body = Bydd { -brand-product-name } yn peidio cydweddu eich cyfrif ond ni fydd yn dileu eich data pori ar y ddyfais hon.
+sync-disconnect-dialog-button = Datgysylltu
+
+fxa-signout-dialog2-title = Allgofnodi o { -fxaccount-brand-name }?
+fxa-signout-dialog-body = Bydd data wedi'i gydweddu'n aros yn eich cyfrif.
+fxa-signout-dialog2-button = Allgofnodi
+fxa-signout-dialog2-checkbox = Dileu data o'r ddyfais hon (mewngofnodion, cyfrineiriau, hanes, nodau tudalen, ac ati).
+
+fxa-menu-sync-settings =
+    .label = Gosodiadau Sync
+fxa-menu-turn-on-sync =
+    .value = Cychwyn Sync
+fxa-menu-turn-on-sync-default = Cychwyn Sync
+
+fxa-menu-connect-another-device =
+    .label = Cysylltu Dyfais Arall…
+
+# This is shown dynamically within "Send tab to device" in fxa menu.
+fxa-menu-send-tab-to-device-syncnotready =
+    .label = Cydweddu Dyfeisiau…
+
+# This is shown within "Send tab to device" in fxa menu if account is not configured.
+fxa-menu-send-tab-to-device-description = Anfon tab ar unwaith i unrhyw ddyfais rydych wedi mewngofnodi arni.
+
+fxa-menu-sign-out =
+    .label = Allgofnodi…
diff --git a/l10n-cy/browser/browser/syncedTabs.ftl b/l10n-cy/browser/browser/syncedTabs.ftl
new file mode 100644
index 0000000000..d183e162dd
--- /dev/null
+++ b/l10n-cy/browser/browser/syncedTabs.ftl
@@ -0,0 +1,73 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+synced-tabs-sidebar-title = Tabiau wedi'u Cydweddu
+synced-tabs-sidebar-noclients-subtitle = Hoffech chi weld eich tabiau o ddyfeisiau eraill yma?
+synced-tabs-sidebar-intro = Gweld rhestr o dabiau o'ch dyfeisiau eraill.
+synced-tabs-sidebar-unverified = Mae angen i'ch cyfrif cael ei gwirio.
+synced-tabs-sidebar-notabs = Dim tabiau agored
+synced-tabs-sidebar-open-settings = Agor gosodiadau Sync
+synced-tabs-sidebar-tabsnotsyncing = Cychwynnwch gydweddu tabiau er mwyn gweld rhestr o dabiau o'ch dyfeisiau eraill.
+synced-tabs-sidebar-connect-another-device = Cysylltu Dyfais Arall
+synced-tabs-sidebar-search =
+    .placeholder = Chwilio tabiau wedi eu cydweddu
+
+## Displayed in the Synced Tabs sidebar's context menu when right-clicking tabs
+## and/or devices in the list. The "Open" strings below should be translated
+## consistently with the equivalent strings for the bookmarks manager's context
+## menu. That menu is activated by right-clicking a bookmark in the Library
+## window. The bookmarks manager context's strings are located in places.ftl.
+
+synced-tabs-context-open =
+    .label = Agor
+    .accesskey = g
+synced-tabs-context-open-in-new-tab =
+    .label = Agor mewn Tab Newydd
+    .accesskey = w
+synced-tabs-context-open-in-new-window =
+    .label = Agor mewn Ffenestr Newydd
+    .accesskey = F
+synced-tabs-context-open-in-new-private-window =
+    .label = Agor Dolen mewn Ffenestr Breifat Newydd
+    .accesskey = N
+synced-tabs-context-bookmark-single-tab =
+    .label = Gosod Nod Tudalen i'r Tab Hwn…
+    .accesskey = N
+synced-tabs-context-open-in-tab =
+    .label = Agor mewn Tab Newydd
+    .accesskey = T
+synced-tabs-context-open-in-container-tab =
+    .label = Agor mewn Tab Cynhwysydd Newydd
+    .accesskey = C
+synced-tabs-context-open-in-window =
+    .label = Agor mewn Ffenestr Newydd
+    .accesskey = F
+synced-tabs-context-open-in-private-window =
+    .label = Agor mewn Ffenestr Breifat Newydd
+    .accesskey = B
+
+##
+
+# Displayed in the Synced Tabs sidebar's context menu when right-clicking tabs
+# and/or devices in the list. This string is for a menuitem equivalent to one in
+# the tab context menu (activated by right-clicking a tab in the tabstrip). That
+# string is located in tabContextMenu.ftl. So, this string should be translated
+# consistently with the "Bookmark Tab…" string there.
+synced-tabs-context-bookmark =
+    .label = Gosod Nod Tudalen i'r Tab
+    .accesskey = T
+synced-tabs-context-copy =
+    .label = Copïo
+    .accesskey = C
+synced-tabs-context-open-all-in-tabs =
+    .label = Agor Popeth mewn Tabiau
+    .accesskey = A
+synced-tabs-context-manage-devices =
+    .label = Rheoli Dyfeisiadau…
+    .accesskey = D
+synced-tabs-context-sync-now =
+    .label = Cydweddu Nawr
+    .accesskey = y
+synced-tabs-fxa-sign-in = Mewngofnodi i gydweddu
+synced-tabs-turn-on-sync = Cychwyn cydweddu
diff --git a/l10n-cy/browser/browser/tabContextMenu.ftl b/l10n-cy/browser/browser/tabContextMenu.ftl
new file mode 100644
index 0000000000..de58dc2703
--- /dev/null
+++ b/l10n-cy/browser/browser/tabContextMenu.ftl
@@ -0,0 +1,132 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+tab-context-new-tab =
+    .label = Tab Newydd
+    .accesskey = T
+reload-tab =
+    .label = Ail lwytho Tab
+    .accesskey = A
+select-all-tabs =
+    .label = Dewis Pob Tab
+    .accesskey = D
+tab-context-play-tab =
+    .label = Chwarae'r Tab
+    .accesskey = h
+tab-context-play-tabs =
+    .label = Chwarae Tabiau
+    .accesskey = C
+duplicate-tab =
+    .label = Dyblygu Tab
+    .accesskey = D
+duplicate-tabs =
+    .label = Tabiau Dyblyg
+    .accesskey = D
+# The following string is displayed on a menuitem that will close the tabs from the start of the tabstrip to the currently targeted tab (excluding the currently targeted and any other selected tabs).
+# In left-to-right languages this should use "Left" and in right-to-left languages this should use "Right".
+close-tabs-to-the-start =
+    .label = Cau Tabiau i'r Chwith
+    .accesskey = h
+# The following string is displayed on a menuitem that will close the tabs from the end of the tabstrip to the currently targeted tab (excluding the currently targeted and any other selected tabs).
+# In left-to-right languages this should use "Right" and in right-to-left languages this should use "Left".
+close-tabs-to-the-end =
+    .label = Cau Tabiau i'r Dde
+    .accesskey = D
+close-other-tabs =
+    .label = Cau Tabiau Eraill
+    .accesskey = C
+reload-tabs =
+    .label = Ail-lwytho Tabiau
+    .accesskey = A
+pin-tab =
+    .label = Pinio Tab
+    .accesskey = P
+unpin-tab =
+    .label = Dadbinio Tab
+    .accesskey = D
+pin-selected-tabs =
+    .label = Pinio Tabiau
+    .accesskey = P
+unpin-selected-tabs =
+    .label = Dadbinio Tabiau
+    .accesskey = b
+bookmark-selected-tabs =
+    .label = Gosod Nod Tudalen i'r Tabiau…
+    .accesskey = T
+bookmark-tab =
+    .label = Gosod Nod Tudalen i'r Tab
+    .accesskey = N
+tab-context-bookmark-tab =
+    .label = Gosod Nod Tudalen i'r Tab
+    .accesskey = T
+tab-context-open-in-new-container-tab =
+    .label = Agor Dolen mewn Tab Cynhwysydd Newydd
+    .accesskey = A
+move-to-start =
+    .label = Symud i'r Cychwyn
+    .accesskey = C
+move-to-end =
+    .label = Symud i'r Diwedd
+    .accesskey = D
+move-to-new-window =
+    .label = Symud i Ffenestr Newydd
+    .accesskey = N
+tab-context-close-multiple-tabs =
+    .label = Cau Tabiau Lluosog
+    .accesskey = L
+tab-context-share-url =
+    .label = Rhannu
+    .accesskey = R
+
+## Variables:
+##  $tabCount (Number): the number of tabs that are affected by the action.
+
+tab-context-reopen-closed-tabs =
+    .label =
+        { $tabCount ->
+            [1] Ailagor Tabiau wedi'u Cau
+            [zero] Ailagor Tabiau wedi'u Cau
+            [one] Ailagor Tab wedi'i Gau
+            [two] Ailagor Tabiau wedi'u Cau
+            [few] Ailagor Tabiau wedi'u Cau
+            [many] Ailagor Tabiau wedi'u Cau
+           *[other] Ailagor Tabiau wedi'u Cau
+        }
+    .accesskey = A
+tab-context-close-n-tabs =
+    .label =
+        { $tabCount ->
+            [1] Cau'r Tab
+            [zero] Cau { $tabCount } Tabiau
+            [one] Cau { $tabCount } Tab
+            [two] Cau { $tabCount } Dab
+            [few] Cau { $tabCount } Thab
+            [many] Cau { $tabCount } Tab
+           *[other] Cau { $tabCount } Tab
+        }
+    .accesskey = T
+tab-context-move-tabs =
+    .label =
+        { $tabCount ->
+            [1] Symud Tab
+            [zero] Symud Tab
+            [one] Symud Tab
+            [two] Symud Tab
+            [few] Symud Tab
+            [many] Symud Tab
+           *[other] Symud Tab
+        }
+    .accesskey = S
+
+tab-context-send-tabs-to-device =
+    .label =
+        { $tabCount ->
+            [zero] Anfon Tab i Ddyfais
+            [one] Anfon { $tabCount } Tab i Ddyfais
+            [two] Anfon { $tabCount } Dab i Ddyfais
+            [few] Anfon { $tabCount } Thab i Ddyfais
+            [many] Anfon { $tabCount } Tab i Ddyfais
+           *[other] Anfon { $tabCount } Thab i Ddyfais
+        }
+    .accesskey = n
diff --git a/l10n-cy/browser/browser/tabbrowser.ftl b/l10n-cy/browser/browser/tabbrowser.ftl
new file mode 100644
index 0000000000..29cdacdc6f
--- /dev/null
+++ b/l10n-cy/browser/browser/tabbrowser.ftl
@@ -0,0 +1,181 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+tabbrowser-empty-tab-title = Tab Newydd
+tabbrowser-empty-private-tab-title = Tab Preifat Newydd
+tabbrowser-menuitem-close-tab =
+    .label = Cau Tab
+tabbrowser-menuitem-close =
+    .label = Cau
+# Displayed as a tooltip on container tabs
+# Variables:
+#   $title (String): the title of the current tab.
+#   $containerName (String): the name of the current container.
+tabbrowser-container-tab-title = { $title } - { $containerName }
+# Variables:
+#   $title (String): the title of the current tab.
+tabbrowser-tab-tooltip =
+    .label = { $title }
+# Variables:
+#   $tabCount (Number): The number of tabs that will be closed.
+tabbrowser-close-tabs-tooltip =
+    .label =
+        { $tabCount ->
+            [zero] Cau tab
+            [one] Cau { $tabCount } tab
+            [two] Cau { $tabCount } dab
+            [few] Cau { $tabCount } tab
+            [many] Cau { $tabCount } tab
+           *[other] Cau { $tabCount } tab
+        }
+
+## Tooltips for tab audio control
+## Variables:
+##   $tabCount (Number): The number of tabs that will be affected.
+
+# Variables:
+#   $shortcut (String): The keyboard shortcut for "Mute tab".
+tabbrowser-mute-tab-audio-tooltip =
+    .label =
+        { $tabCount ->
+            [zero] Tewi tab ({ $shortcut })
+            [one] Tewi { $tabCount } tab ({ $shortcut })
+            [two] Tewi { $tabCount } tab ({ $shortcut })
+            [few] Tewi { $tabCount } tab ({ $shortcut })
+            [many] Tewi { $tabCount } tab ({ $shortcut })
+           *[other] Tewi { $tabCount } tab ({ $shortcut })
+        }
+# Variables:
+#   $shortcut (String): The keyboard shortcut for "Unmute tab".
+tabbrowser-unmute-tab-audio-tooltip =
+    .label =
+        { $tabCount ->
+            [zero] Dad-dewi tab ({ $shortcut })
+            [one] Dad-dewi { $tabCount } tab ({ $shortcut })
+            [two] Dad-dewi { $tabCount } tab ({ $shortcut })
+            [few] Dad-dewi { $tabCount } tab ({ $shortcut })
+            [many] Dad-dewi { $tabCount } tab ({ $shortcut })
+           *[other] Dad-dewi { $tabCount } tab ({ $shortcut })
+        }
+tabbrowser-mute-tab-audio-background-tooltip =
+    .label =
+        { $tabCount ->
+            [zero] Tewi tab
+            [one] Tewi { $tabCount } tab
+            [two] Tewi { $tabCount } tab
+            [few] Tewi { $tabCount } tab
+            [many] Tewi { $tabCount } tab
+           *[other] Tewi { $tabCount } tab
+        }
+tabbrowser-unmute-tab-audio-background-tooltip =
+    .label =
+        { $tabCount ->
+            [zero] Dad-dewi tab
+            [one] Dad-dewi { $tabCount } tab
+            [two] Dad-dewi { $tabCount } tab
+            [few] Dad-dewi { $tabCount } tab
+            [many] Dad-dewi { $tabCount } tab
+           *[other] Dad-dewi { $tabCount } tab
+        }
+tabbrowser-unblock-tab-audio-tooltip =
+    .label =
+        { $tabCount ->
+            [zero] Chwarae tab
+            [one] Chwarae { $tabCount } tab
+            [two] Chwarae { $tabCount } tab
+            [few] Chwarae { $tabCount } tab
+            [many] Chwarae { $tabCount } tab
+           *[other] Chwarae { $tabCount } tab
+        }
+
+## Confirmation dialog when closing a window with more than one tab open,
+## or when quitting when only one window is open.
+
+# The singular form is not considered since this string is used only for multiple tabs.
+# Variables:
+#   $tabCount (Number): The number of tabs that will be closed.
+tabbrowser-confirm-close-tabs-title =
+    { $tabCount ->
+        [zero] Cau { $tabCount } tabiau?
+        [one] Cau { $tabCount } tab?
+        [two] Cau { $tabCount } tab?
+        [few] Cau { $tabCount } tab?
+        [many] Cau { $tabCount } tab?
+       *[other] Cau { $tabCount } tab?
+    }
+tabbrowser-confirm-close-tabs-button = Cau tabiau
+tabbrowser-confirm-close-tabs-checkbox = Cadarnhau cyn cau tabiau lluosog
+
+## Confirmation dialog when quitting using the menu and multiple windows are open.
+
+# The forms for 0 or 1 items are not considered since this string is used only for
+# multiple windows.
+# Variables:
+#   $windowCount (Number): The number of windows that will be closed.
+tabbrowser-confirm-close-windows-title =
+    { $windowCount ->
+        [zero] Cau { $windowCount } ffenestri?
+        [one] Cau { $windowCount } ffenestr?
+        [two] Cau { $windowCount } ffenestr?
+        [few] Cau { $windowCount } ffenestr?
+        [many] Cau { $windowCount } ffenestr?
+       *[other] Cau { $windowCount } ffenestr?
+    }
+tabbrowser-confirm-close-windows-button =
+    { PLATFORM() ->
+        [windows] Cau a gadael
+       *[other] Cau a gadael
+    }
+
+## Confirmation dialog when quitting using the keyboard shortcut (Ctrl/Cmd+Q)
+## Windows does not show a prompt on quit when using the keyboard shortcut by default.
+
+tabbrowser-confirm-close-tabs-with-key-title = Cau ffenestr a gadael { -brand-short-name }?
+tabbrowser-confirm-close-tabs-with-key-button = Gadael { -brand-short-name }
+# Variables:
+#   $quitKey (String): the text of the keyboard shortcut for quitting.
+tabbrowser-confirm-close-tabs-with-key-checkbox = Cadarnhau cyn gadael gyda { $quitKey }
+
+## Confirmation dialog when opening multiple tabs simultaneously
+
+tabbrowser-confirm-open-multiple-tabs-title = Cadarnhau ar agor
+# Variables:
+#   $tabCount (Number): The number of tabs that will be opened.
+tabbrowser-confirm-open-multiple-tabs-message =
+    { $tabCount ->
+       *[other] Rydych ar fin agor { $tabCount } tab. Gall hyn arafu { -brand-short-name } tra fo'r tudalennau'n llwytho. Ydych chi'n siŵr eich bod am barhau?
+    }
+tabbrowser-confirm-open-multiple-tabs-button = Agor tabiau
+tabbrowser-confirm-open-multiple-tabs-checkbox = Rhybuddio y gall agor tabiau niferus arafu { -brand-short-name }
+
+## Confirmation dialog for enabling caret browsing
+
+tabbrowser-confirm-caretbrowsing-title = Pori Caret
+tabbrowser-confirm-caretbrowsing-message = Mae pwyso F7 yn cychwyn a diffodd Pori Caret. Mae'r nodwedd hon yn gosod cyrchwr symudol ar dudalennau gwe, gan ganiatáu i chi ddewis testun gyda'r bysellfwrdd. Hoffech chi gychwyn Pori Caret?
+tabbrowser-confirm-caretbrowsing-checkbox = Peidio dangos y blwch deialog yma eto.
+
+##
+
+# Variables:
+#   $domain (String): URL of the page that is trying to steal focus.
+tabbrowser-allow-dialogs-to-get-focus =
+    .label = Caniatáu i hysbysiadau fel hyn o { $domain } fynd â chi i'w tab
+tabbrowser-customizemode-tab-title = Cyfaddasu { -brand-short-name }
+
+## Context menu buttons, of which only one will be visible at a time
+
+tabbrowser-context-mute-tab =
+    .label = Tewi Tab
+    .accesskey = T
+tabbrowser-context-unmute-tab =
+    .label = Tab Dad-dewi
+    .accesskey = D
+# The accesskey should match the accesskey for tabbrowser-context-mute-tab
+tabbrowser-context-mute-selected-tabs =
+    .label = Tewi Tabiau
+    .accesskey = T
+# The accesskey should match the accesskey for tabbrowser-context-unmute-tab
+tabbrowser-context-unmute-selected-tabs =
+    .label = Dad-dewi Tabiau
+    .accesskey = t
diff --git a/l10n-cy/browser/browser/textRecognition.ftl b/l10n-cy/browser/browser/textRecognition.ftl
new file mode 100644
index 0000000000..033da0c068
--- /dev/null
+++ b/l10n-cy/browser/browser/textRecognition.ftl
@@ -0,0 +1,15 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+## Text recognition works through a modal that presents the text that is found
+## in an image, and copies the results to the clipboard.
+
+text-recognition-modal-searching-title = Wrthi'n chwilio delwedd am destun…
+text-recognition-modal-results-title = Testun wedi'i gopïo o'r ddelwedd
+text-recognition-modal-no-results-title = Ymddiheuriadau, nid oedd modd i ni echdynnu unrhyw destun. Rhowch gynnig ar ddelwedd wahanol. <a data-l10n-name="error-link">Dysgu rhagor</a>.
+text-recognition-modal-close-button = Cau
+
+# The title of the the modal is only available to screen readers.
+text-recognition-modal-accessible-modal-title = Canlyniadau echdynnu testun
diff --git a/l10n-cy/browser/browser/toolbarContextMenu.ftl b/l10n-cy/browser/browser/toolbarContextMenu.ftl
new file mode 100644
index 0000000000..6aca5b8ddf
--- /dev/null
+++ b/l10n-cy/browser/browser/toolbarContextMenu.ftl
@@ -0,0 +1,87 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+toolbar-context-menu-new-tab =
+    .label = Tab Newydd
+    .accesskey = N
+toolbar-context-menu-reload-selected-tab =
+    .label = Ail Lwytho'r Tab Hwn
+    .accesskey = A
+toolbar-context-menu-reload-selected-tabs =
+    .label = Ail Lwytho'r Tabiau Hyn
+    .accesskey = A
+toolbar-context-menu-bookmark-selected-tab =
+    .label = Gosod Nod Tudalen i'r Tab Hwn…
+    .accesskey = T
+toolbar-context-menu-bookmark-selected-tabs =
+    .label = Gosod Nod Tudalen i'r Tabiau Hyn…
+    .accesskey = T
+toolbar-context-menu-select-all-tabs =
+    .label = Dewis Pob Tab
+    .accesskey = D
+toolbar-context-menu-reopen-closed-tabs =
+    .label =
+        { $tabCount ->
+            [1] Ailagor Tabiau wedi'u Cau
+            [zero] Ailagor Tabiau wedi'u Cau
+            [one] Ailagor Tab wedi'i Gau
+            [two] Ailagor Tabiau wedi'u Cau
+            [few] Ailagor Tabiau wedi'u Cau
+            [many] Ailagor Tabiau wedi'u Cau
+           *[other] Ailagor Tabiau wedi'u Cau
+        }
+    .accesskey = o
+toolbar-context-menu-manage-extension =
+    .label = Rheoli Estyniad
+    .accesskey = E
+toolbar-context-menu-remove-extension =
+    .label = Tynnu'r Estyniad
+    .accesskey = T
+# This label is used in the extensions toolbar buttons context menus,
+# a user can use this command to submit to Mozilla an abuse report
+# related to that extension. "Report" is a verb.
+toolbar-context-menu-report-extension =
+    .label = Adrodd ar yr Estyniad
+    .accesskey = A
+# Can appear on the same context menu as toolbar-context-menu-menu-bar-cmd
+# ("Menu Bar") and personalbarCmd ("Bookmarks Toolbar"), so they should
+# have different access keys.
+toolbar-context-menu-pin-to-overflow-menu =
+    .label = Pinio i'r Ddewislen Ychwanegol
+    .accesskey = P
+toolbar-context-menu-auto-hide-downloads-button-2 =
+    .label = Cuddio Botwm pan yn Wag
+    .accesskey = B
+toolbar-context-menu-always-open-downloads-panel =
+    .label = Dangos y Panel Pan fydd y Llwytho'n Dechrau
+    .accesskey = D
+toolbar-context-menu-remove-from-toolbar =
+    .label = Tynnu o'r Bar Offer
+    .accesskey = T
+toolbar-context-menu-view-customize-toolbar =
+    .label = Cyfaddasu…
+    .accesskey = y
+toolbar-context-menu-view-customize-toolbar-2 =
+    .label = Cyfaddasu'r Bar Offer…
+    .accesskey = O
+# This is only ever shown when toolbar-context-menu-pin-to-overflow-menu
+# is hidden, so they can share access keys.
+toolbar-context-menu-pin-to-toolbar =
+    .label = Pinio i'r Bar Offer
+    .accesskey = P
+toolbar-context-menu-bookmarks-toolbar-always-show-2 =
+    .label = Dangos Bob Tro
+    .accesskey = D
+toolbar-context-menu-bookmarks-toolbar-never-show-2 =
+    .label = Peidio Dangos Byth
+    .accesskey = P
+toolbar-context-menu-bookmarks-toolbar-on-new-tab-2 =
+    .label = Dangos ar Dab Newydd yn Unig
+    .accesskey = U
+toolbar-context-menu-bookmarks-show-other-bookmarks =
+    .label = Dangos Nodau Tudalen Eraill
+    .accesskey = N
+toolbar-context-menu-menu-bar-cmd =
+    .toolbarname = Bar Dewislen
+    .accesskey = B
diff --git a/l10n-cy/browser/browser/touchbar/touchbar.ftl b/l10n-cy/browser/browser/touchbar/touchbar.ftl
new file mode 100644
index 0000000000..dfbf66b719
--- /dev/null
+++ b/l10n-cy/browser/browser/touchbar/touchbar.ftl
@@ -0,0 +1,38 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# Strings in this file are used to localize button titles displayed on the 
+# MacBook Touch Bar.
+back = Nôl
+forward = Ymlaen
+reload = Ail-lwytho
+home = Cartref
+fullscreen = Sgrin Lawn
+touchbar-fullscreen-exit = Gadael Sgrin Lawn
+find = Canfod
+new-tab = Tab newydd
+add-bookmark = Ychwanegu nod tudalen
+reader-view = Golwg Darllen
+# Meant to match the string displayed in an empty URL bar.
+open-location = Chwilio neu rhoi cyfeiriad
+share = Rhannu
+close-window = Cau Ffenestr
+open-sidebar = Barrau Ochr
+
+# This string describes shortcuts for search.
+search-popover = Chwilio llwybrau byr
+# Describes searches limited to a specific scope
+# (e.g. searching only in history).
+search-search-in = Chwilio yn:
+
+## Various categories of shortcuts for search.
+
+search-bookmarks = Nodau Tudalen
+search-history = Hanes
+search-opentabs = Tabiau Agored
+search-tags = Tagiau
+search-titles = Teitlau
+
+##
+
diff --git a/l10n-cy/browser/browser/translationNotification.ftl b/l10n-cy/browser/browser/translationNotification.ftl
new file mode 100644
index 0000000000..709aa31d1d
--- /dev/null
+++ b/l10n-cy/browser/browser/translationNotification.ftl
@@ -0,0 +1,74 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+## These 2 strings are used to construct a sentence that contains a dropdown
+## showing the detected language of the current web page.
+## In en-US it looks like this:
+##   This page is in [detected language] Translate this page?
+## "detected language" here is a language name coming from the
+## toolkit/intl/languageNames.ftl file; for some locales it may not be in
+## the correct grammar case to keep the same structure of the original
+## sentence.
+
+translation-notification-this-page-is-in =
+    .value = Mae'r dudalen yn
+translation-notification-translate-this-page =
+    .value = Cyfieithu'r dudalen?
+
+##
+
+translation-notification-translate-button =
+    .label = Cyfieithu
+translation-notification-not-now-button =
+    .label = Nid Nawr
+translation-notification-translating-content =
+    .value = Cyfieithu cynnwys y dudalen…
+
+## These 3 strings are used to construct a sentence that contains 2 dropdowns
+## showing the source and target language of a translated web page.
+## In en-US it looks like this:
+##   This page has been translated from [from language] to [to language]
+## "from language" and "to language" here are language names coming from the
+## toolkit/intl/languageNames.ftl file; for some locales they may not be in
+## the correct grammar case to keep the same structure of the original
+## sentence.
+
+translation-notification-translated-from =
+    .value = Mae'r dudalen wedi ei chyfieithu o'r
+translation-notification-translated-to =
+    .value = at
+# This string (empty in en-US) is for locales that need to display some text
+# after the second drop down for the sentence to be grammatically correct.
+translation-notification-translated-to-suffix =
+    .value = { "" }
+
+##
+
+translation-notification-show-original-button =
+    .label = Dangos y Gwreiddiol
+translation-notification-show-translation-button =
+    .label = Dangos y Cyfieithiad
+translation-notification-error-translating =
+    .value = Bu gwall wrth gyfieithu'r dudalen hon.
+translation-notification-try-again-button =
+    .label = Ceisio Eto
+translation-notification-service-unavailable =
+    .value = Nid yw cyfieithu ar gael ar hyn o bryd. Ceisiwch eto.
+translation-notification-options-menu =
+    .label = Dewisiadau
+
+## The accesskey values used here should not clash with each other
+
+# Variables:
+#  $langName (String): a language name coming from the toolkit/intl/languageNames.ftl file.
+translation-notification-options-never-for-language =
+    .label = Peidio cyfieithu { $langName }
+    .accesskey = P
+translation-notification-options-never-for-site =
+    .label = Peidio byth cyfieithu'r wefan hon
+    .accesskey = b
+translation-notification-options-preferences =
+    .label = Dewisiadau cyfieithu
+    .accesskey = D
diff --git a/l10n-cy/browser/browser/unifiedExtensions.ftl b/l10n-cy/browser/browser/unifiedExtensions.ftl
new file mode 100644
index 0000000000..1dfe6efc49
--- /dev/null
+++ b/l10n-cy/browser/browser/unifiedExtensions.ftl
@@ -0,0 +1,34 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+### These strings appear in the Unified Extensions panel.
+
+
+## Panel
+
+unified-extensions-header-title = Estyniadau
+unified-extensions-manage-extensions =
+    .label = Rheoli estyniadau
+
+## An extension in the main list
+
+# Each extension in the unified extensions panel (list) has a secondary button
+# to open a context menu. This string is used for each of these buttons.
+# Variables:
+#   $extensionName (String) - Name of the extension
+unified-extensions-item-open-menu =
+    .aria-label = Agor dewislen ar gyfer { $extensionName }
+unified-extensions-item-message-manage = Rheoli estyniadau
+
+## Extension's context menu
+
+unified-extensions-context-menu-pin-to-toolbar =
+    .label = Pinio i'r Bar Offer
+unified-extensions-context-menu-manage-extension =
+    .label = Rheoli Estyniad
+unified-extensions-context-menu-remove-extension =
+    .label = Tynnu Estyniad
+unified-extensions-context-menu-report-extension =
+    .label = Adrodd ar yr Estyniad
diff --git a/l10n-cy/browser/browser/webauthnDialog.ftl b/l10n-cy/browser/browser/webauthnDialog.ftl
new file mode 100644
index 0000000000..d7c8c8f46e
--- /dev/null
+++ b/l10n-cy/browser/browser/webauthnDialog.ftl
@@ -0,0 +1,17 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# Variables:
+#  $retriesLeft (Number): number of tries left
+webauthn-pin-invalid-prompt =
+    { $retriesLeft ->
+        [0] PIN anghywir! Rhowch y PIN cywir ar gyfer eich dyfais.
+        [zero] PIN anghywir! Rhowch y PIN cywir ar gyfer eich dyfais.
+        [one] PIN anghywir! Rhowch y PIN cywir ar gyfer eich dyfais. Mae gennych { $retriesLeft } ymgais ar ôl.
+        [two] PIN anghywir! Rhowch y PIN cywir ar gyfer eich dyfais. Mae gennych { $retriesLeft } ymgais ar ôl.
+        [few] PIN anghywir! Rhowch y PIN cywir ar gyfer eich dyfais. Mae gennych { $retriesLeft } ymgais ar ôl.
+        [many] PIN anghywir! Rhowch y PIN cywir ar gyfer eich dyfais. Mae gennych { $retriesLeft } ymgais ar ôl.
+       *[other] PIN anghywir! Rhowch y PIN cywir ar gyfer eich dyfais. Mae gennych { $retriesLeft } ymgais ar ôl.
+    }
+webauthn-pin-required-prompt = Rhowch y PIN ar gyfer eich dyfais.
diff --git a/l10n-cy/browser/browser/webrtcIndicator.ftl b/l10n-cy/browser/browser/webrtcIndicator.ftl
new file mode 100644
index 0000000000..975077c567
--- /dev/null
+++ b/l10n-cy/browser/browser/webrtcIndicator.ftl
@@ -0,0 +1,246 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+# Note: This is currently placed under browser/base/content so that we can
+# get the strings to appear without having our localization community need
+# to go through and translate everything. Once these strings are ready for
+# translation, we'll move it to the locales folder.
+
+
+## These strings are used so that the window has a title in tools that
+## enumerate/look for window titles. It is not normally visible anywhere.
+
+webrtc-indicator-title = { -brand-short-name } - Dangosydd rhannu
+webrtc-indicator-window =
+    .title = { -brand-short-name } - Dangosydd rhannu
+
+## Used as list items in sharing menu
+
+webrtc-item-camera = camera
+webrtc-item-microphone = meicroffon
+webrtc-item-audio-capture = tab sain
+webrtc-item-application = rhaglen
+webrtc-item-screen = sgrin
+webrtc-item-window = ffenestr
+webrtc-item-browser = tab
+
+##
+
+# This is used for the website origin for the sharing menu if no readable origin could be deduced from the URL.
+webrtc-sharing-menuitem-unknown-host = Tarddiad anhysbys
+# Variables:
+#   $origin (String): The website origin (e.g. www.mozilla.org)
+#   $itemList (String): A formatted list of items (e.g. "camera, microphone and tab audio")
+webrtc-sharing-menuitem =
+    .label = { $origin } ({ $itemList })
+webrtc-sharing-menu =
+    .label = Tabiau dyfeisiau sy'n rhannu
+    .accesskey = d
+webrtc-sharing-window = Rydych yn rhannu ffenestr rhaglen arall.
+webrtc-sharing-browser-window = Rydych chi'n rhannu { -brand-short-name }.
+webrtc-sharing-screen = Rydych yn rhannu'ch sgrin gyfan.
+webrtc-stop-sharing-button = Peidio Rhannu
+webrtc-microphone-unmuted =
+    .title = Diffodd y meicroffon
+webrtc-microphone-muted =
+    .title = Troi'r meicroffon ymlaen
+webrtc-camera-unmuted =
+    .title = Diffodd y meicroffon
+webrtc-camera-muted =
+    .title = Troi'r camera ymlaen
+webrtc-minimize =
+    .title = Lleihau'r dangosydd
+
+## These strings will display as a tooltip on supported systems where we show
+## device sharing state in the OS notification area. We do not use these strings
+## on macOS, as global menu bar items do not have native tooltips.
+
+webrtc-camera-system-menu =
+    .label = Rydych yn rhannu'ch camera. Cliciwch i reoli rhannu.
+webrtc-microphone-system-menu =
+    .label = Rydych yn rhannu'ch meicroffon. Cliciwch i reoli rhannu.
+webrtc-screen-system-menu =
+    .label = Rydych yn rhannu ffenestr neu sgrin. Cliciwch i reoli rhannu.
+
+## Tooltips used by the legacy global sharing indicator
+
+webrtc-indicator-sharing-camera-and-microphone =
+    .tooltiptext = Mae eich camera a'ch meicroffon yn cael eu rhannu. Cliciwch i reoli'r rhannu.
+webrtc-indicator-sharing-camera =
+    .tooltiptext = Mae eich camera'n cael ei rannu. Cliciwch i reoli'r rhannu.
+webrtc-indicator-sharing-microphone =
+    .tooltiptext = Mae eich meicroffon yn cael ei rannu. Cliciwch i reoli'r rhannu.
+webrtc-indicator-sharing-application =
+    .tooltiptext = Mae rhaglen yn ei rannu. Cliciwch i reoli'r rhannu.
+webrtc-indicator-sharing-screen =
+    .tooltiptext = Mae eich sgrin yn cael ei rannu. Cliciwch i reoli'r rhannu.
+webrtc-indicator-sharing-window =
+    .tooltiptext = Mae ffenestr yn cael ei rannu. Cliciwch i reoli'r rhannu.
+webrtc-indicator-sharing-browser =
+    .tooltiptext = Mae tab yn cael ei rannu. Cliciwch i reoli'r rhannu.
+
+## These strings are only used on Mac for menus attached to icons
+## near the clock on the mac menubar.
+## Variables:
+##   $streamTitle (String): the title of the tab using the share.
+##   $tabCount (Number): the title of the tab using the share.
+
+webrtc-indicator-menuitem-control-sharing =
+    .label = Rhannu Rheoli
+webrtc-indicator-menuitem-control-sharing-on =
+    .label = Rheoli Rhannu gyda "{ $streamTitle }"
+webrtc-indicator-menuitem-sharing-camera-with =
+    .label = Rhannu camera gyda "{ $streamTitle }"
+webrtc-indicator-menuitem-sharing-camera-with-n-tabs =
+    .label =
+        { $tabCount ->
+            [zero] Peidio rhannu Camera gyda thabiau
+            [one] Rhannu Camera gyda { $tabCount } tab
+            [two] Rhannu Camera gyda { $tabCount } dab
+            [few] Rhannu Camera gyda { $tabCount } thab
+            [many] Rhannu Camera gyda { $tabCount } thab
+           *[other] Rhannu Camera gyda { $tabCount } tab
+        }
+webrtc-indicator-menuitem-sharing-microphone-with =
+    .label = Rhannu Meicroffon gyda "{ $streamTitle }"
+webrtc-indicator-menuitem-sharing-microphone-with-n-tabs =
+    .label =
+        { $tabCount ->
+            [zero] Peidio rhannu Meicroffon gyda thabiau
+            [one] Rhannu Meicroffon gydag { $tabCount } tab
+            [two] Rhannu Meicroffon gyda { $tabCount } dab
+            [few] Rhannu Meicroffon gyda { $tabCount } thab
+            [many] Rhannu Meicroffon gyda { $tabCount } thab
+           *[other] Rhannu Meicroffon gyda { $tabCount } tab
+        }
+webrtc-indicator-menuitem-sharing-application-with =
+    .label = Rhannu Rhaglen gyda "{ $streamTitle }"
+webrtc-indicator-menuitem-sharing-application-with-n-tabs =
+    .label =
+        { $tabCount ->
+            [zero] Peidio rhannu Rhaglen gyda thabiau
+            [one] Rhannu Rhaglen gyda { $tabCount } tab
+            [two] Rhannu Rhaglen gyda { $tabCount } dab
+            [few] Rhannu Rhaglen gyda { $tabCount } thab
+            [many] Rhannu Rhaglen gyda { $tabCount } thab
+           *[other] Rhannu Rhaglen gyda { $tabCount } tab
+        }
+webrtc-indicator-menuitem-sharing-screen-with =
+    .label = Rhannu Sgrin gyda "{ $streamTitle }"
+webrtc-indicator-menuitem-sharing-screen-with-n-tabs =
+    .label =
+        { $tabCount ->
+            [zero] Peidio rhannu'r Sgrin gyda thabiau
+            [one] Rhannu'r Sgrin gyda { $tabCount } tab
+            [two] Rhannu'r Sgrin gyda { $tabCount } dab
+            [few] Rhannu'r Sgrin gyda { $tabCount } thab
+            [many] Rhannu'r Sgrin gyda { $tabCount } thab
+           *[other] Rhannu'r Sgrin gyda { $tabCount } tab
+        }
+webrtc-indicator-menuitem-sharing-window-with =
+    .label = Rhannu Ffenestr gyda "{ $streamTitle }"
+webrtc-indicator-menuitem-sharing-window-with-n-tabs =
+    .label =
+        { $tabCount ->
+            [zero] Peidio rhannu Ffenestr gyda thabiau
+            [one] Rhannu Ffenestr gydag { $tabCount } tab
+            [two] Rhannu Ffenestr gyda { $tabCount } dab
+            [few] Rhannu Ffenestr gyda { $tabCount } thab
+            [many] Rhannu Ffenestr gyda { $tabCount } thab
+           *[other] Rhannu Ffenestr gyda { $tabCount } tab
+        }
+webrtc-indicator-menuitem-sharing-browser-with =
+    .label = Rhannu Tab gyda "{ $streamTitle }"
+# This message is shown when the contents of a tab is shared during a WebRTC
+# session, which currently is only possible with Loop/Hello.
+webrtc-indicator-menuitem-sharing-browser-with-n-tabs =
+    .label =
+        { $tabCount ->
+            [zero] Peidio rhannu Tab gyda thabiau
+            [one] Rhannu Tab gydag { $tabCount } tab
+            [two] Rhannu Tab gyda { $tabCount } dab
+            [few] Rhannu Tab gyda { $tabCount } thab
+            [many] Rhannu Tab gyda { $tabCount } thab
+           *[other] Rhannu Tab gyda { $tabCount } tab
+        }
+
+## Variables:
+##   $origin (String): the website origin (e.g. www.mozilla.org).
+
+webrtc-allow-share-audio-capture = Caniatáu i { $origin } wrando ar sain y tab hwn?
+webrtc-allow-share-camera = Caniatáu i { $origin } ddefnyddio’ch camera?
+webrtc-allow-share-microphone = Caniatáu i { $origin } ddefnyddio’ch meicroffon?
+webrtc-allow-share-screen = Caniatáu i { $origin } weld eich sgrin?
+# "Speakers" is used in a general sense that might include headphones or
+# another audio output connection.
+webrtc-allow-share-speaker = Caniatáu i { $origin } ddefnyddio seinyddion eraill?
+webrtc-allow-share-camera-and-microphone = Caniatáu i { $origin } ddefnyddio'ch camera a'ch meicroffon?
+webrtc-allow-share-camera-and-audio-capture = Caniatáu i { $origin } ddefnyddio'ch camera a gwrando ar sain y tab hwn?
+webrtc-allow-share-screen-and-microphone = Caniatáu i { $origin } ddefnyddio'ch meicroffon a gweld eich sgrin?
+webrtc-allow-share-screen-and-audio-capture = Caniatáu i { $origin } wrando ar sain y tab hwn a gweld eich sgrin?
+
+## Variables:
+##   $origin (String): the first party origin.
+##   $thirdParty (String): the third party origin.
+
+webrtc-allow-share-audio-capture-unsafe-delegation = Caniatáu i { $origin } roi caniatâd i { $thirdParty } wrando ar sain y tab hwn?
+webrtc-allow-share-camera-unsafe-delegation = Caniatáu i { $origin } roi mynediad i { $thirdParty } at eich camera?
+webrtc-allow-share-microphone-unsafe-delegations = Caniatáu i { $origin } roi mynediad i { $thirdParty } i'ch meicroffon?
+webrtc-allow-share-microphone-unsafe-delegation = Caniatáu i { $origin } roi mynediad i { $thirdParty } i'ch meicroffon?
+webrtc-allow-share-screen-unsafe-delegation = Caniatáu i { $origin } roi caniatâd i { $thirdParty } weld eich sgrin?
+# "Speakers" is used in a general sense that might include headphones or
+# another audio output connection.
+webrtc-allow-share-speaker-unsafe-delegation = Caniatáu i { $origin } roi mynediad  i { $thirdParty } i seinyddion eraill?
+webrtc-allow-share-camera-and-microphone-unsafe-delegation = Caniatáu i { $origin } roi mynediad i { $thirdParty } i'ch camera a'ch meicroffon?
+webrtc-allow-share-camera-and-audio-capture-unsafe-delegation = Caniatáu i { $origin } roi mynediad i { $thirdParty } at eich camera a gwrando ar sain y tab hwn?
+webrtc-allow-share-screen-and-microphone-unsafe-delegation = Caniatáu i { $origin } roi mynediad i { $thirdParty } i'ch meicroffon a gweld eich sgrin?
+webrtc-allow-share-screen-and-audio-capture-unsafe-delegation = Caniatáu i { $origin } roi caniatâd i { $thirdParty } wrando ar sain y tab hwn a gweld eich sgrin?
+
+##
+
+webrtc-share-screen-warning = Rhannwch dim ond sgriniau â gwefannau rydych chi'n ymddiried ynddyn nhw. Gall rhannu ganiatáu i wefannau twyllodrus bori fel taw chi sydd wrthi a dwyn eich data preifat.
+webrtc-share-browser-warning = Rhannwch { -brand-short-name } dim ond gyda gwefannau rydych yn ymddiried ynddyn nhw. Gall rhannu ganiatáu i wefannau twyllodrus bori fel taw chi sydd wrthi a dwyn eich data preifat.
+webrtc-share-screen-learn-more = Dysgu Rhagor
+webrtc-pick-window-or-screen = Dewiswch Ffenestr neu Sgrin
+webrtc-share-entire-screen = Sgrin gyfan
+webrtc-share-pipe-wire-portal = Defnyddio gosodiadau'r system weithredu
+# Variables:
+#   $monitorIndex (String): screen number (digits 1, 2, etc).
+webrtc-share-monitor = Sgrin { $monitorIndex }
+# Variables:
+#   $windowCount (Number): the number of windows currently displayed by the application.
+#   $appName (String): the name of the application.
+webrtc-share-application =
+    { $windowCount ->
+        [zero] { $appName } (Dim ffenestri)
+        [one] { $appName } ({ $windowCount } ffenestr)
+        [two] { $appName } ({ $windowCount } ffenestr)
+        [few] { $appName } ({ $windowCount } ffenestr)
+        [many] { $appName } ({ $windowCount } ffenestr)
+       *[other] { $appName } ({ $windowCount } ffenestr)
+    }
+
+## These buttons are the possible answers to the various prompts in the "webrtc-allow-share-*" strings.
+
+webrtc-action-allow =
+    .label = Caniatáu
+    .accesskey = C
+webrtc-action-block =
+    .label = Rhwystro
+    .accesskey = R
+webrtc-action-always-block =
+    .label = Rhwystro bob tro
+    .accesskey = b
+webrtc-action-not-now =
+    .label = Nid nawr
+    .accesskey = N
+
+##
+
+webrtc-remember-allow-checkbox = Cofio'r penderfyniad yma
+webrtc-mute-notifications-checkbox = Tewi hysbysiadau gwefan tra'n rhannu
+webrtc-reason-for-no-permanent-allow-screen = Nid yw { -brand-short-name } yn caniatáu mynediad parhaus i'ch sgrin.
+webrtc-reason-for-no-permanent-allow-audio = Nid yw { -brand-short-name } yn gallu caniatáu mynediad parhaol i sain eich tab heb ofyn pa dab i'w rannu.
+webrtc-reason-for-no-permanent-allow-insecure = Nid yw eich cysylltiad a'r wefan hon y ddiogel. Er mwyn eich diogelu, dim ond ar gyfer y sesiwn yma y bydd { -brand-short-name } yn caniatáu mynediad.
diff --git a/l10n-cy/browser/chrome/browser/accounts.properties b/l10n-cy/browser/chrome/browser/accounts.properties
new file mode 100644
index 0000000000..a331492d55
--- /dev/null
+++ b/l10n-cy/browser/chrome/browser/accounts.properties
@@ -0,0 +1,112 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# LOCALIZATION NOTE (reconnectDescription) - %S = Email address of user's Firefox Account
+reconnectDescription = Ailgysylltu %S
+
+# LOCALIZATION NOTE (verifyDescription) - %S = Email address of user's Firefox Account
+verifyDescription = Dilysu %S
+
+# These strings are shown in a desktop notification after the
+# user requests we resend a verification email.
+verificationSentTitle = Dilysiad wedi'i anfon
+# LOCALIZATION NOTE (verificationSentBody) - %S = Email address of user's Firefox Account
+verificationSentBody = Mae dolen dilysu wedi'i anfon at %S.
+verificationNotSentTitle = Methu Anfon y Dilysiad
+verificationNotSentBody = Nid ydym yn gallu anfon e-bost dilysu ar hy o bryd, ceisiwch eto'n hwyrach.
+
+# LOCALIZATION NOTE (deviceConnDisconnTitle) - the title shown in a notification
+# when either this device or another device has connected to, or disconnected
+# from, a Firefox Account.
+deviceConnDisconnTitle = Cyfrif Firefox
+
+# LOCALIZATION NOTE (otherDeviceConnectedBody, otherDeviceConnectedBody.noDeviceName)
+# These strings are used in a notification shown when a new device joins the
+# Firefox account.
+# %S is the name of the new device; otherDeviceConnectedBody.noDeviceName is shown
+# instead of otherDeviceConnectedBody when the name is not known.
+otherDeviceConnectedBody = Mae'r cyfrifiadur hwn bellach wedi'i gysylltu i %S.
+otherDeviceConnectedBody.noDeviceName = Mae'r cyfrifiadur hwn bellach wedi'i gysylltu i ddyfais newydd.
+
+# LOCALIZATION NOTE (thisDeviceConnectedBody) - used in a notification shown
+# after a Firefox Account is connected to the current device.
+thisDeviceConnectedBody = Rydych wedi mewngofnodi'n llwyddiannus
+
+# LOCALIZATION NOTE (thisDeviceDisconnectedBody) - used in a notification shown
+# after the Firefox Account was disconnected remotely.
+thisDeviceDisconnectedBody = Mae'r cyfrifiadur hwn wedi'i ddatgysylltu.
+
+# LOCALIZATION NOTE (sendToAllDevices.menuitem)
+# Displayed in the Send Tab/Page/Link to Device context menu when right clicking a tab, a page or a link.
+sendToAllDevices.menuitem = Anfon i Bob Dyfais
+
+# LOCALIZATION NOTE (manageDevices.menuitem)
+# Displayed in the Send Tab/Page/Link to Device context menu when right clicking a tab, a page or a link.
+manageDevices.menuitem = Rheoli Dyfeisiadau…
+
+# LOCALIZATION NOTE (sendTabToDevice.unconfigured, sendTabToDevice.unconfigured.label2)
+# Displayed in the Send Tabs context menu when right clicking a tab, a page or a link
+# and the Sync account is unconfigured. Redirects to a marketing page.
+sendTabToDevice.unconfigured.label2 = Heb Fewngofnodi
+sendTabToDevice.unconfigured = Dysgu am Anfon Tabiau…
+
+# LOCALIZATION NOTE (sendTabToDevice.signintofxa)
+# Displayed in the Send Tabs context menu and the page action panel when FxA is not
+# configured. Allows users to immediately sign into FxA via the preferences.
+# %S is replaced by brandProductName.
+sendTabToDevice.signintofxa = Mewngofnodi i %S…
+
+# LOCALIZATION NOTE (sendTabToDevice.singledevice, sendTabToDevice.connectdevice,
+# sendTabToDevice.singledevice.status)
+# Displayed in the Send Tabs context menu when right clicking a tab, a page or a link
+# and the Sync account has only 1 device. The sendTabToDevice.singledevice link
+# redirects to a marketing page, the sendTabToDevice.connectdevice redirects
+# to an FxAccounts page that tells to you to connect another device.
+sendTabToDevice.singledevice.status = Dim Dyfais wedi ei Gysylltu
+sendTabToDevice.singledevice = Dysgu am Anfon Tabiau…
+sendTabToDevice.connectdevice = Cysylltu Dyfais Arall…
+
+# LOCALIZATION NOTE (sendTabToDevice.verify, sendTabToDevice.verify.status)
+# Displayed in the Send Tabs context menu when right clicking a tab, a page or a link
+# and the Sync account is unverified. Redirects to the Sync preferences page.
+sendTabToDevice.verify.status = Cyfrif Heb ei Wirio
+sendTabToDevice.verify = Gwiriwch eich Cyfrif…
+
+# LOCALIZATION NOTE (tabArrivingNotification.title, tabArrivingNotificationWithDevice.title,
+# multipleTabsArrivingNotification.title, unnamedTabsArrivingNotification2.body,
+# unnamedTabsArrivingNotificationMultiple2.body, unnamedTabsArrivingNotificationNoDevice.body,
+# singleTabArrivingWithTruncatedURL.body)
+# These strings are used in a notification shown when we're opening tab(s) another device sent us to display.
+
+# LOCALIZATION NOTE (tabArrivingNotification.title, tabArrivingNotificationWithDevice.title)
+# The body for these is the URL of the tab received
+tabArrivingNotification.title = Tab wedi'i Dderbyn
+# LOCALIZATION NOTE (tabArrivingNotificationWithDevice.title) %S is the device name
+tabArrivingNotificationWithDevice.title = Tab gan %S
+
+multipleTabsArrivingNotification.title = Tab wedi'i Dderbyn
+# LOCALIZATION NOTE (unnamedTabsArrivingNotification2.body):
+# Semi-colon list of plural forms.
+# See: http://developer.mozilla.org/en/docs/Localization_and_Plurals
+# #1 is the number of tabs received and #2 is the device name.
+unnamedTabsArrivingNotification2.body = Nid oes tabiau wedi cyrraedd #2;Mae #1 tab wedi cyrraedd o #2;Mae #1 dab wedi cyrraedd o #2;Mae #1 thab wedi cyrraedd o #2;Mae #1 tab wedi cyrraedd o #2;Mae #1 tab wedi cyrraedd o #2
+# LOCALIZATION NOTE (unnamedTabsArrivingNotificationMultiple2.body):
+# Semi-colon list of plural forms.
+# See: http://developer.mozilla.org/en/docs/Localization_and_Plurals
+# #1 is the number of tabs received.
+unnamedTabsArrivingNotificationMultiple2.body = Nid oes tabiau wedi cyrraedd o'ch ddyfeisiau cysylltiedig;Mae #1 tab wedi cyrraedd o'ch ddyfeisiau cysylltiedig;Mae #1 dab wedi cyrraedd o'ch ddyfeisiau cysylltiedig;Mae #1 thab wedi cyrraedd o'ch ddyfeisiau cysylltiedig;Mae #1 tab wedi cyrraedd o'ch ddyfeisiau cysylltiedig;Mae #1 tab wedi cyrraedd o'ch ddyfeisiau cysylltiedig
+
+# LOCALIZATION NOTE (unnamedTabsArrivingNotificationNoDevice.body):
+# Semi-colon list of plural forms.
+# See: http://developer.mozilla.org/en/docs/Localization_and_Plurals
+# #1 is the number of tabs received
+# This version is used when we don't know any device names.
+unnamedTabsArrivingNotificationNoDevice.body = Nid oes tabiau wedi cyrraedd;Mae #1 tab wedi cyrraedd;Mae #1 dab wedi cyrraedd;Mae #1 thab wedi cyrraedd;Mae #1 tab wedi cyrraedd;Mae #1 tab wedi cyrraedd
+
+# LOCALIZATION NOTE (singleTabArrivingWithTruncatedURL.body):
+# Used when a tab from a remote device arrives but the URL must be truncated.
+# Should display the URL with an indication that it's benen truncated.
+# %S is the portion of the URL that remains after truncation.
+singleTabArrivingWithTruncatedURL.body = %S…
+
diff --git a/l10n-cy/browser/chrome/browser/browser.properties b/l10n-cy/browser/chrome/browser/browser.properties
new file mode 100644
index 0000000000..a82227e8c9
--- /dev/null
+++ b/l10n-cy/browser/chrome/browser/browser.properties
@@ -0,0 +1,1064 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+nv_timeout=Daeth yr amser i ben
+openFile=Agor Ffeil
+
+droponhometitle=Gosod Tudalen Cartref
+droponhomemsg=Ydych chi am i'r ddogfen fod yn dudalen cartref newydd i chi?
+droponhomemsgMultiple=Hoffech chi i'r dogfennau hyn fod yn dudalennau cartref newydd i chi?
+
+# context menu strings
+
+# LOCALIZATION NOTE (contextMenuSearch): %1$S is the search engine,
+# %2$S is the selection string.
+contextMenuSearch=Chwilio %1$S am "%2$S"
+contextMenuSearch.accesskey=C
+contextMenuPrivateSearch=Chwilio mewn Ffenestr Breifat
+contextMenuPrivateSearch.accesskey=h
+# LOCALIZATION NOTE (contextMenuPrivateSearchOtherEngine): %S is the search
+# engine name as set for Private Browsing mode. This label is only used when
+# this engine is different from the default engine name used in normal mode.
+contextMenuPrivateSearchOtherEngine=Chwilio gyda %S mewn Ffenestr Breifat
+contextMenuPrivateSearchOtherEngine.accesskey=h
+
+# bookmark dialog strings
+
+bookmarkAllTabsDefault=[Enw Ffolder]
+
+xpinstallPromptMessage=Rhwystrodd %S y wefan rhag gofyn i chi osod meddalwedd ar eich cyfrifiadur.
+# LOCALIZATION NOTE (xpinstallPromptMessage.header)
+# The string contains the hostname of the site the add-on is being installed from.
+xpinstallPromptMessage.header=Caniatáu i %S osod ategyn?
+xpinstallPromptMessage.message=Rydych yn ceisio gosod ychwanegyn o %S. Gwnewch yn siŵr eich bod yn ymddiried yn y wefan hon cyn parhau.
+xpinstallPromptMessage.header.unknown=Caniatáu i wefan anhysbys osod ategyn?
+xpinstallPromptMessage.message.unknown=Rydych yn ceisio gosod ychwanegyn o wefan anhysbys. Gwnewch yn siŵr eich bod yn ymddiried yn y wefan hon cyn parhau.
+xpinstallPromptMessage.learnMore=Dysgwch ragor am osod ategion yn ddiogel
+xpinstallPromptMessage.dontAllow=Peidio â Chaniatáu
+xpinstallPromptMessage.dontAllow.accesskey=P
+xpinstallPromptMessage.neverAllow=Byth Caniatáu
+xpinstallPromptMessage.neverAllow.accesskey=B
+# LOCALIZATION NOTE (xpinstallPromptMessage.neverAllowAndReport)
+# Long text in this context make the dropdown menu extend awkwardly to the left, avoid
+# a localization that's significantly longer than the English version.
+xpinstallPromptMessage.neverAllowAndReport=Adrodd am Wefan Amheus
+xpinstallPromptMessage.neverAllowAndReport.accesskey=A
+# LOCALIZATION NOTE (sitePermissionInstallFirstPrompt.header)
+# This message is shown when a SitePermissionsAddon install is triggered, i.e. when the
+# website calls sensitive APIs (e.g. navigator.requestMIDIAccess).
+sitePermissionInstallFirstPrompt.header=Mae'r wefan hon yn gofyn am fynediad i'ch dyfeisiau. Mae modd galluogi mynediad dyfais trwy osod ychwanegyn.
+# LOCALIZATION NOTE (sitePermissionInstallFirstPrompt.message)
+# This message is shown when a SitePermissionsAddon install is triggered, i.e. when the
+# website calls sensitive APIs (e.g. navigator.requestMIDIAccess).
+sitePermissionInstallFirstPrompt.message=Mae modd defnyddio'r ychwanegyn hwn i ddwyn eich data neu ymosod ar eich cyfrifiadur. Ewch ymlaen dim ond os ydych yn ymddiried yn y wefan hon.
+
+# Accessibility Note:
+# Be sure you do not choose an accesskey that is used elsewhere in the active context (e.g. main menu bar, submenu of the warning popup button)
+# See https://website-archive.mozilla.org/www.mozilla.org/access/access/keyboard/ for details
+xpinstallPromptMessage.install=Ymlaen i'r Gosod
+xpinstallPromptMessage.install.accesskey=G
+
+xpinstallDisabledMessageLocked=Mae gosod meddalwedd wedi ei analluogi gan eich gweinyddwr system.
+xpinstallDisabledMessage=Mae gosod meddalwedd wedi ei analluogi. Cliciwch Galluogi a cheisio eto.
+xpinstallDisabledButton=Galluogi
+xpinstallDisabledButton.accesskey=a
+
+# LOCALIZATION NOTE (addonInstallBlockedByPolicy)
+# This message is shown when the installation of an add-on is blocked by
+# enterprise policy. %1$S is replaced by the name of the add-on.
+# %2$S is replaced by the ID of add-on. %3$S is a custom message that
+# the administration can add to the message.
+addonInstallBlockedByPolicy=Mae %1$S (%2$S) wedi ei analluogi gan eich gweinyddwr system.%3$S
+# LOCALIZATION NOTE (addonDomainBlockedByPolicy)
+# This message is shown when the installation of add-ons from a domain
+# is blocked by enterprise policy.
+addonDomainBlockedByPolicy=Rhwystrodd eich gweinyddwr systemau y wefan hon rhag gofyn i chi osod meddalwedd ar eich cyfrifiadur.
+addonInstallFullScreenBlocked=Nid yw gosod ychwanegiad yn cael ei ganiatáu wrth fynd i'r modd sgrin lawn neu cyn hynny.
+
+# LOCALIZATION NOTE (webextPerms.header,webextPerms.headerWithPerms,webextPerms.headerUnsigned,webextPerms.headerUnsignedWithPerms)
+# This string is used as a header in the webextension permissions dialog,
+# %S is replaced with the localized name of the extension being installed.
+# See https://bug1308309.bmoattachments.org/attachment.cgi?id=8814612
+# for an example of the full dialog.
+# Note, this string will be used as raw markup. Avoid characters like <, >, &
+webextPerms.header=Ychwanegu %S?
+webextPerms.headerWithPerms=Ychwanegu %S? Bydd gan yr estyniad hwn ganiatâd i:
+webextPerms.headerUnsigned=Ychwanegu %S? Nid yw'r estyniad hwn wedi'i wirio. Gall estyniadau maleisus ddwyn eich manylion preifat neu gyfaddawdu eich cyfrifiadur. Ychwanegwch ef dim ond os ydych chi'n ymddiried yn y ffynhonnell.
+webextPerms.headerUnsignedWithPerms=Ychwanegu %S? Nid yw'r estyniad hwn wedi'i wirio. Gall estyniadau maleisus ddwyn eich manylion preifat neu gyfaddawdu eich cyfrifiadur. Ychwanegwch ef dim ond os ydych chi'n ymddiried yn y ffynhonnell. Bydd gan yr estyniad hwn ganiatâd i:
+
+webextPerms.learnMore2=Dysgu rhagor
+webextPerms.add.label=Ychwanegu
+webextPerms.add.accessKey=Y
+webextPerms.cancel.label=Diddymu
+webextPerms.cancel.accessKey=D
+
+# LOCALIZATION NOTE (webextPerms.sideloadMenuItem)
+# %1$S will be replaced with the localized name of the sideloaded add-on.
+# %2$S will be replace with the name of the application (e.g., Firefox, Nightly)
+webextPerms.sideloadMenuItem=Mae %1$S wedi ei ychwanegu at %2$S
+
+# LOCALIZATION NOTE (webextPerms.sideloadHeader)
+# This string is used as a header in the webextension permissions dialog
+# when the extension is side-loaded.
+# %S is replaced with the localized name of the extension being installed.
+# Note, this string will be used as raw markup. Avoid characters like <, >, &
+webextPerms.sideloadHeader=Mae %S wedi ei ychwanegu
+webextPerms.sideloadText2=Mae rhaglen arall ar eich cyfrifiadur wedi gosod ychwanegyn y gall effeithio ar eich porwr. Darllenwch geisiadau caniatâd yr ychwanegyn a dewis i Alluogi neu Ddiddymu (ei adael wedi ei analluogi).
+webextPerms.sideloadTextNoPerms=Mae rhaglen arall ar eich cyfrifiadur wedi gosod ychwanegyn y gall effeithio ar eich porwr. Darllenwch geisiadau caniatâd yr ychwanegyn a dewis i Alluogi neu Ddiddymu (i'w adael wedi ei analluogi).
+
+webextPerms.sideloadEnable.label=Galluogi
+webextPerms.sideloadEnable.accessKey=G
+webextPerms.sideloadCancel.label=Diddymu
+webextPerms.sideloadCancel.accessKey=D
+
+# LOCALIZATION NOTE (webextPerms.updateMenuItem)
+# %S will be replaced with the localized name of the extension which
+# has been updated.
+webextPerms.updateMenuItem=Mae %S angen caniatâd newydd
+
+# LOCALIZATION NOTE (webextPerms.updateText)
+# %S is replaced with the localized name of the updated extension.
+# Note, this string will be used as raw markup. Avoid characters like <, >, &
+webextPerms.updateText2=Mae %S wedi'i ddiweddaru. Rhaid i chi gymeradwyo caniatâd newydd cyn y bydd y fersiwn wedi'i ddiweddaru'n cael ei osod. Bydd dewis “Diddymu” yn cynnal eich fersiwn estyniad cyfredol. Bydd gan yr estyniad hwn ganiatâd i:
+
+webextPerms.updateAccept.label=Diweddaru
+webextPerms.updateAccept.accessKey=D
+
+# LOCALIZATION NOTE (webextPerms.optionalPermsHeader)
+# %S is replace with the localized name of the extension requested new
+# permissions.
+# Note, this string will be used as raw markup. Avoid characters like <, >, &
+webextPerms.optionalPermsHeader=Mae %S yn gofyn am ganiatâd ychwanegol.
+webextPerms.optionalPermsListIntro=Mae eisiau:
+webextPerms.optionalPermsAllow.label=Caniatáu
+webextPerms.optionalPermsAllow.accessKey=C
+webextPerms.optionalPermsDeny.label=Gwrthod
+webextPerms.optionalPermsDeny.accessKey=G
+
+webextPerms.description.bookmarks=Darllen a newid nodau tudalen
+webextPerms.description.browserSettings=Darllen a newid gosodiadau'r porwr
+webextPerms.description.browsingData=Clirio'r hanes pori diweddar, cwcis a data cysylltiedig
+webextPerms.description.clipboardRead=Estyn data o'r clipfwrdd
+webextPerms.description.clipboardWrite=Mewnbynnu data i'r clipfwrdd
+webextPerms.description.declarativeNetRequest=Rhwystro cynnwys ar unrhyw dudalen
+webextPerms.description.devtools=Estyn offer datblygwyr i gael mynediad at eich data mewn tabiau agored
+webextPerms.description.downloads=Llwytho i lawr, darllen ffeiliau a newid hanes llwytho i lawr y porwr
+webextPerms.description.downloads.open=Agor ffeiliau a llwythwyd i lawr i'ch cyfrifiadur
+webextPerms.description.find=Darllen testun yr holl dabiau sydd ar agor
+webextPerms.description.geolocation=Mynediad i'ch lleoliad
+webextPerms.description.history=Mynediad at eich hanes pori
+webextPerms.description.management=Monitro'r defnydd o estyniadau a rheoli themâu
+# LOCALIZATION NOTE (webextPerms.description.nativeMessaging)
+# %S will be replaced with the name of the application
+webextPerms.description.nativeMessaging=Cyfnewid negeseuon gyda rhaglenni ar wahân i %S
+webextPerms.description.notifications=Dangos hysbysiadau i chi
+webextPerms.description.pkcs11=Darparu gwasanaethau dilysiad cryptograffig
+webextPerms.description.privacy=Darllen a newid gosodiadau preifatrwydd
+webextPerms.description.proxy=Rheoli gosodiadau dirprwy'r porwr
+webextPerms.description.sessions=Mynediad at y tabiau caewyd yn ddiweddar
+webextPerms.description.tabs=Mynediad at dabiau'r porwyr
+webextPerms.description.tabHide=Cuddio a dangos tabiau'r porwr
+webextPerms.description.topSites=Mynediad at eich hanes pori
+webextPerms.description.webNavigation=Cael mynediad at weithgaredd wrth lywio
+
+webextPerms.hostDescription.allUrls=Cael mynediad at eich data ar gyfer pob gwefan
+
+# LOCALIZATION NOTE (webextPerms.hostDescription.wildcard)
+# %S will be replaced by the DNS domain for which a webextension
+# is requesting access (e.g., mozilla.org)
+webextPerms.hostDescription.wildcard=Cael mynediad at eich data ym mhob gwefan ym mharth %S
+
+# LOCALIZATION NOTE (webextPerms.hostDescription.tooManyWildcards):
+# Semi-colon list of plural forms.
+# See: http://developer.mozilla.org/en/docs/Localization_and_Plurals
+# #1 will be replaced by an integer indicating the number of additional
+# domains for which this webextension is requesting permission.
+webextPerms.hostDescription.tooManyWildcards=Peidio cael mynediad at eich data mewn parthau eraill;Cael mynediad at eich data mewn #1 parth arall;Cael mynediad at eich data mewn #1 barth arall;Cael mynediad at eich data mewn #1 parth arall;Cael mynediad at eich data mewn #1 parth arall;Cael mynediad at eich data mewn #1 parth arall
+
+# LOCALIZATION NOTE (webextPerms.hostDescription.oneSite)
+# %S will be replaced by the DNS host name for which a webextension
+# is requesting access (e.g., www.mozilla.org)
+webextPerms.hostDescription.oneSite=Cael mynediad at eich data yn %S
+
+# LOCALIZATION NOTE (webextPerms.hostDescription.tooManySites)
+# Semi-colon list of plural forms.
+# See: http://developer.mozilla.org/en/docs/Localization_and_Plurals
+# #1 will be replaced by an integer indicating the number of additional
+# hosts for which this webextension is requesting permission.
+webextPerms.hostDescription.tooManySites=Peidio cael mynediad at eich data mewn gwefannau eraill;Cael mynediad at eich data mewn #1 gwefan arall;Cael mynediad at eich data mewn #1 wefan arall;Cael mynediad at eich data mewn #1 gwefan arall;Cael mynediad at eich data mewn #1 gwefan arall;Cael mynediad at eich data mewn #1 gwefan arall
+
+# LOCALIZATION NOTE (webextSitePerms.headerWithPerms,webextSitePerms.headerUnsignedWithPerms)
+# This string is used as a header in the webextension permissions dialog,
+# %1$S is replaced with the localized name of the extension being installed.
+# %2$S will be replaced by the DNS host name for which a webextension enables permissions
+# Note, this string will be used as raw markup. Avoid characters like <, >, &
+webextSitePerms.headerWithPerms=Ychwanegu %1$S? Mae'r estyniad hwn yn rhoi'r galluoedd canlynol i %2$S:
+webextSitePerms.headerUnsignedWithPerms=Ychwanegu %1$S? Nid yw'r estyniad hwn wedi'i wirio. Gall estyniadau maleisus ddwyn eich manylion preifat neu gyfaddawdu eich cyfrifiadur. Ychwanegwch ef dim ond os ydych chi'n ymddiried yn y ffynhonnell. Mae'r estyniad hwn yn rhoi'r galluoedd canlynol i %2$S:
+
+# LOCALIZATION NOTE (webextSitePerms.headerWithGatedPerms.midi)
+# This string is used as a header in the webextension permissions dialog for synthetic add-ons.
+# The part of the string describing what privileges the extension gives should be consistent
+# with the value of webextSitePerms.description.{sitePermission}.
+# %S is the hostname of the site the add-on is being installed from.
+# Note, this string will be used as raw markup. Avoid characters like <, >, &
+webextSitePerms.headerWithGatedPerms.midi=Mae'r ychwanegyn hwn yn rhoi mynediad i %S i'ch dyfeisiau MIDI.
+
+# LOCALIZATION NOTE (webextSitePerms.headerWithGatedPerms.midi-sysex)
+# This string is used as a header in the webextension permissions dialog for synthetic add-ons.
+# The part of the string describing what privileges the extension gives should be consistent
+# with the value of webextSitePerms.description.{sitePermission}.
+# %S is the hostname of the site the add-on is being installed from.
+# Note, this string will be used as raw markup. Avoid characters like <, >, &
+webextSitePerms.headerWithGatedPerms.midi-sysex=Mae'r ychwanegyn hwn yn rhoi mynediad i %S i'ch dyfeisiau MIDI (gyda chefnogaeth SysEx).
+
+# LOCALIZATION NOTE (webextSitePerms.descriptionGatedPerms)
+# This string is used as description in the webextension permissions dialog for synthetic add-ons.
+# %S will be replaced by the DNS host name for which a webextension enables permissions
+# Note, this string will be used as raw markup. Avoid characters like <, >, &
+webextSitePerms.descriptionGatedPerms=Gall y mynediad hwn fod yn beryglus, ac mae'n caniatáu i'r wefan weithredu fel meddalwedd sydd wedi'i osod ar eich cyfrifiadur.
+
+# These should remain in sync with permissions.NAME.label in sitePermissions.properties
+webextSitePerms.description.midi=Mynediad at ddyfeisiau MIDI
+webextSitePerms.description.midi-sysex=Mynediad at ddyfeisiau MIDI sydd â Chefnogaeth SysEx
+
+# LOCALIZATION NOTE (webext.defaultSearch.description)
+# %1$S is replaced with the localized named of the extension that is asking to change the default search engine.
+# %2$S is replaced with the name of the current search engine
+# %3$S is replaced with the name of the new search engine
+webext.defaultSearch.description=Mae %1$S eisiau newid eich peiriant chwilio rhagosodedig o %2$S i %3$S. Ydy hynny'n iawn?
+webext.defaultSearchYes.label=Iawn
+webext.defaultSearchYes.accessKey=I
+webext.defaultSearchNo.label=Na
+webext.defaultSearchNo.accessKey=N
+
+# LOCALIZATION NOTE (webext.remove.confirmation.message)
+# %1$S is the name of the extension which is about to be removed.
+# %2$S is brandShorterName
+webext.remove.confirmation.message=Tynnu %1$S o %2$S?
+webext.remove.confirmation.button=Tynnu
+
+# LOCALIZATION NOTE (addonPostInstall.message3)
+# %S is replaced with the localized named of the extension that was
+# just installed.
+addonPostInstall.message3=Ychwanegwyd %S
+
+# LOCALIZATION NOTE (addonDownloadingAndVerifying):
+# Semicolon-separated list of plural forms. See:
+# http://developer.mozilla.org/en/docs/Localization_and_Plurals
+# Also see https://bugzilla.mozilla.org/show_bug.cgi?id=570012 for mockups
+addonDownloadingAndVerifying=Llwytho i lawr a dilysu #1 ychwanegion…;Llwytho i lawr a dilysu #1 ychwanegyn…;Llwytho i lawr a dilysu #1 ychwanegyn…;Llwytho i lawr a dilysu #1 ychwanegyn…;Llwytho i lawr a dilysu #1 ychwanegyn…;Llwytho i lawr a dilysu #1 ychwanegyn…
+addonDownloadVerifying=Dilysu
+
+addonInstall.unsigned=(Heb eu gwirio)
+addonInstall.cancelButton.label=Diddymu
+addonInstall.cancelButton.accesskey=D
+addonInstall.acceptButton2.label=Ychwanegu
+addonInstall.acceptButton2.accesskey=Y
+
+# LOCALIZATION NOTE (addonConfirmInstallMessage,addonConfirmInstallUnsigned):
+# Semicolon-separated list of plural forms. See:
+# http://developer.mozilla.org/en/docs/Localization_and_Plurals
+# #1 is brandShortName
+# #2 is the number of add-ons being installed
+addonConfirmInstall.message=Hoffai'r wefan hon osod ychwanegyn yn #1:;Hoffai'r wefan hon osod #2 ychwanegyn yn #1:;Hoffai'r wefan hon osod #2 ychwanegyn yn #1:;Hoffai'r wefan hon osod #2 ychwanegyn yn #1:;Hoffai'r wefan hon osod #2 ychwanegyn yn #1:;Hoffai'r wefan hon osod #2 ychwanegyn yn #1:
+addonConfirmInstallUnsigned.message=Rhybudd: Hoffai'r wefan hon osod ychwanegyn heb ei wirio yn #1. Mentrwch ar eich risg eich hun.;Rhybudd: Hoffai'r wefan hon osod #2 ychwanegyn heb eu gwirio yn #1. Mentrwch ar eich risg eich hun.
+
+# LOCALIZATION NOTE (addonConfirmInstallSomeUnsigned.message):
+# Semicolon-separated list of plural forms. See:
+# http://developer.mozilla.org/en/docs/Localization_and_Plurals
+# #1 is brandShortName
+# #2 is the total number of add-ons being installed (at least 2)
+addonConfirmInstallSomeUnsigned.message=Rhybudd: Hoffai'r wefan hon osod #2 ychwanegion yn #1, mae rhai ohonynt heb eu gwirio. Gwnewch hyn ar eich menter eich hun.;Rhybudd: Hoffai'r wefan hon osod #2 ychwanegyn yn #1, mae rhai ohonynt heb eu gwirio. Gwnewch hyn ar eich menter eich hun.;Rhybudd: Hoffai'r wefan hon osod #2 ychwanegyn yn #1, mae rhai ohonynt heb eu gwirio. Gwnewch hyn ar eich menter eich hun.;Rhybudd: Hoffai'r wefan hon osod #2 ychwanegyn yn #1, mae rhai ohonynt heb eu gwirio. Gwnewch hyn ar eich menter eich hun.;Rhybudd: Hoffai'r wefan hon osod #2 ychwanegyn yn #1, mae rhai ohonynt heb eu gwirio. Gwnewch hyn ar eich menter eich hun.;Rhybudd: Hoffai'r wefan hon osod #2 ychwanegyn yn #1, mae rhai ohonynt heb eu gwirio. Gwnewch hyn ar eich menter eich hun.
+
+# LOCALIZATION NOTE (addonInstalled):
+# %S is the name of the add-on
+addonInstalled=Mae %S wedi'i osod yn llwyddiannus.
+# LOCALIZATION NOTE (addonsGenericInstalled):
+# Semicolon-separated list of plural forms. See:
+# http://developer.mozilla.org/en/docs/Localization_and_Plurals
+# #1 number of add-ons
+addonsGenericInstalled=Nid oes ychwanegion wedi eu gosod.;Mae #1 ychwanegyn wedi ei osod yn llwyddiannus.;Mae #1 ychwanegyn wedi eu gosod yn llwyddiannus.;Mae #1 ychwanegyn wedi eu gosod yn llwyddiannus.;Mae #1 ychwanegyn wedi eu gosod yn llwyddiannus.;Mae #1 ychwanegyn wedi eu gosod yn llwyddiannus.
+
+# LOCALIZATION NOTE (addonInstallError-1, addonInstallError-2, addonInstallError-3, addonInstallError-4, addonInstallError-5, addonInstallError-8, addonLocalInstallError-1, addonLocalInstallError-2, addonLocalInstallError-3, addonLocalInstallError-4, addonLocalInstallError-5):
+# %1$S is the application name, %2$S is the add-on name
+addonInstallError-1=Nid oedd modd llwytho'r ychwanegyn i lawr oherwydd methiant y cysylltiad.
+addonInstallError-2=Nid oedd modd gosod yr ychwanegyn am nad yw'n cydweddu â'r ychwanegyn roedd %1$S yn ei ddisgwyl.
+addonInstallError-3=Nid oedd modd llwytho'r ychwanegyn i lawr o'r wefan hon oherwydd ei fod yn ymddangos yn llwgr.
+addonInstallError-4=Nid oedd modd gosod %2$S gan nad oedd %1$S yn gallu newid y linell angenrheidiol.
+addonInstallError-5=Mae %1$S wedi atal y wefan rhag gosod ychwanegyn sydd heb ei wirio.
+addonInstallError-8=Nid oes modd gosod yr ychwanegyn %2$S o'r lleoliad hwn.
+addonLocalInstallError-1=Nid oedd modd gosod yr ychwanegyn oherwydd gwall system.
+addonLocalInstallError-2=Nid oedd modd gosod yr ychwanegyn am nad yw'n cydweddu â'r ychwanegyn %1$S disgwyliwyd.
+addonLocalInstallError-3=Nid oedd modd gosod yr ychwanegyn am ei fod yn edrych yn llwgr.
+addonLocalInstallError-4=Nid oedd modd gosod %2$S gan nad oedd %1$S yn gallu newid y linell angenrheidiol.
+addonLocalInstallError-5=Nid oedd modd gosod yr ychwanegyn am nad yw wedi ei wirio.
+
+# LOCALIZATION NOTE (addonInstallErrorIncompatible):
+# %1$S is the application name, %2$S is the application version, %3$S is the add-on name
+addonInstallErrorIncompatible=Nid oedd modd gosod %3$S am nad yw'n cydweddu â %1$S %2$S.
+
+# LOCALIZATION NOTE (addonInstallErrorBlocklisted): %S is add-on name
+addonInstallErrorBlocklisted=Nid oedd modd gosod %S am fod risg uchel iddo achosi problemau sefydlogrwydd a diogelwch.
+
+unsignedAddonsDisabled.message=Mae un neu fwy o ychwanegion nad oedd modd eu gwirio wedi eu hanalluogi.
+unsignedAddonsDisabled.learnMore.label=Dysgu Rhagor
+unsignedAddonsDisabled.learnMore.accesskey=D
+
+# LOCALIZATION NOTE (popupWarning.message): Semicolon-separated list of plural forms.
+# See: http://developer.mozilla.org/en/docs/Localization_and_Plurals
+# #1 is brandShortName and #2 is the number of pop-ups blocked.
+popupWarning.message=Nid yw gwefan #1 wedi rhwystro rhag agor llamlenni.;Rhwystrodd #1 y wefan rhag agor #2 llamlen.;Rhwystrodd #1 y wefan rhag agor #2 llamlen.;Rhwystrodd #1 y wefan rhag agor #2 llamlen.;Rhwystrodd #1 y wefan rhag agor #2 llamlen.;Rhwystrodd #1 y wefan rhag agor #2 llamlen.
+# LOCALIZATION NOTE (popupWarning.exceeded.message): Semicolon-separated list of plural forms.
+# See: http://developer.mozilla.org/en/docs/Localization_and_Plurals
+# The singular form is left empty for English, since the number of blocked pop-ups is always greater than 1.
+# #1 is brandShortName and #2 is the number of pop-ups blocked.
+popupWarning.exceeded.message=;Rhwystrodd #1 y wefan hon rhag agor mwy na #2 llamlen.;Rhwystrodd #1 y wefan hon rhag agor mwy na #2 llamlen.;Rhwystrodd #1 y wefan hon rhag agor mwy na #2 llamlen.;Rhwystrodd #1 y wefan hon rhag agor mwy na #2 llamlen.;Rhwystrodd #1 y wefan hon rhag agor mwy na #2 llamlen.
+popupWarningButton=Opsiynau
+popupWarningButton.accesskey=D
+popupWarningButtonUnix=Dewisiadau
+popupWarningButtonUnix.accesskey=D
+popupShowPopupPrefix=Dangos '%S'
+
+# LOCALIZATION NOTE (geolocationLastAccessIndicatorText): %S is the relative time of the most recent geolocation access (e.g. 5 min. ago)
+geolocationLastAccessIndicatorText=Mynediad diwethaf %S
+
+# LOCALIZATION NOTE (openProtocolHandlerPermissionEntryLabel): %S is the scheme of the protocol the site may open an application for. For example: mailto
+openProtocolHandlerPermissionEntryLabel=Dolenni %S://
+
+crashedpluginsMessage.title=Mae'r ategyn %S wedi chwalu.
+crashedpluginsMessage.reloadButton.label=Ail lwytho tudalen
+crashedpluginsMessage.reloadButton.accesskey=A
+crashedpluginsMessage.submitButton.label=Cyflwyno adroddiad chwalu
+crashedpluginsMessage.submitButton.accesskey=C
+crashedpluginsMessage.learnMore=Dysgu Rhagor…
+
+# Keyword fixup messages
+# LOCALIZATION NOTE (keywordURIFixup.message): Used when the user tries to visit
+# a local host page, by the time the DNS request recognizes it, we have already
+# loaded a search page for the given word.  An infobar then asks to the user
+# whether he rather wanted to visit the host.  %S is the recognized host.
+keywordURIFixup.message=Oeddech chi'n bwriadu mynd i %S?
+keywordURIFixup.goTo=Oeddwn, cymrwch fi i %S
+keywordURIFixup.goTo.accesskey=O
+
+pluginInfo.unknownPlugin=Anhysbys
+
+# Flash activation doorhanger UI
+flashActivate.message=Hoffech chi adael i Adobe Flash redeg ar y wefan hon? Caniatewch Adobe Flash i redeg ar wefannau rydych yn ymddiried ynddyn nhw.
+flashActivate.outdated.message=Ydych chi eisiau rhedeg hen fersiwn o Adobe Flash ar y wefan hon? Gall hen fersiwn effeithio ar berfformiad a diogelwch eich porwr.
+flashActivate.noAllow=Peidio â Chaniatáu
+flashActivate.allow=Caniatáu
+flashActivate.noAllow.accesskey=P
+flashActivate.allow.accesskey=C
+
+# in-page UI
+# LOCALIZATION NOTE (PluginClickToActivate2): Two changes were done to the
+# previous version of the string. The first is that we changed the wording from
+# "Activate" to "Run", because it's shorter and feels less technical in English.
+# Feel free to keep using the previous wording in your language if it's already
+# the best one.
+# The second change is that we removed the period at the end of the phrase, because
+# it's not natural in our UI, and the underline was removed from this, so it doesn't
+# look like a link anymore. We suggest that everyone removes that period too.
+PluginClickToActivate2=Rhedeg %S
+PluginVulnerableUpdatable=Mae'r ategyn yma'n fregus a dylai gael ei ddiweddaru.
+PluginVulnerableNoUpdate=Mae diogelwch yr ategyn yma'n fregus.
+
+# Sanitize
+# LOCALIZATION NOTE (update.downloadAndInstallButton.label): %S is replaced by the
+# version of the update: "Update to 28.0".
+update.downloadAndInstallButton.label=Diweddaru %S
+update.downloadAndInstallButton.accesskey=D
+
+menuOpenAllInTabs.label=Agor pob Tab
+
+# History menu
+# LOCALIZATION NOTE (menuUndoCloseWindowLabel): Semicolon-separated list of plural forms.
+# see bug 394759
+# See: http://developer.mozilla.org/en/docs/Localization_and_Plurals
+# #1 Window Title, #2 Number of tabs
+menuUndoCloseWindowLabel=#1 (a dim tabiau eraill);#1 (a #2 tab arall);#1 (a #2 dab arall);#1 (a #2 thab arall);#1 (a #2 tab arall);#1 (a #2 tab arall)
+menuUndoCloseWindowSingleTabLabel=#1
+
+# Unified Back-/Forward Popup
+tabHistory.current=Aros ar y dudalen hon
+
+# Unified Back-/Forward Popup
+tabHistory.reloadCurrent=Ail lwytho'r dudalen hon
+tabHistory.goBack=Nôl i'r dudalen hon
+tabHistory.goForward=Mynd ymlaen i'r dudalen hon
+
+# URL Bar
+pasteAndGo.label=Gludo a Mynd
+# LOCALIZATION NOTE (reloadButton.tooltip):
+# %S is the keyboard shortcut for reloading the current page
+reloadButton.tooltip=Ail lwytho'r dudalen gyfredol (%S)
+# LOCALIZATION NOTE (stopButton.tooltip):
+# %S is the keyboard shortcut for stopping loading the page
+stopButton.tooltip=Peidio llwytho'r dudalen hon (%S)
+# LOCALIZATION NOTE (urlbar-zoom-button.tooltip):
+# %S is the keyboard shortcut for resetting the zoom level to 100%
+urlbar-zoom-button.tooltip=Ailosod lefel chwyddo (%S)
+# LOCALIZATION NOTE (reader-mode-button.tooltip):
+# %S is the keyboard shortcut for entering/exiting reader view
+reader-mode-button.tooltip=Toglo golwg darllenydd (%S)
+
+# LOCALIZATION NOTE(zoom-button.label): %S is the current page zoom level,
+# %% will be displayed as a single % character (% is commonly used to define
+# format specifiers, so it needs to be escaped).
+zoom-button.label = %S%%
+
+# Block autorefresh
+refreshBlocked.goButton=Caniatáu
+refreshBlocked.goButton.accesskey=C
+refreshBlocked.refreshLabel=Rhwystrodd %S y dudalen hon rhag ailagor yn awtomatig.
+refreshBlocked.redirectLabel=Rhwystrodd %S y dudalen hon rhag ailgyfeirio i dudalen arall.
+
+# General bookmarks button
+# LOCALIZATION NOTE (bookmarksMenuButton.tooltip):
+# %S is the keyboard shortcut for "Show All Bookmarks"
+bookmarksMenuButton.tooltip=Dangos eich nodau tudalen (%S)
+
+# Downloads button tooltip
+# LOCALIZATION NOTE (downloads.tooltip):
+# %S is the keyboard shortcut for "Downloads"
+downloads.tooltip=Dangos cynnydd y llwytho i lawr cyfredol (%S)
+
+# New Window button tooltip
+# LOCALIZATION NOTE (newWindowButton.tooltip):
+# %S is the keyboard shortcut for "New Window"
+newWindowButton.tooltip=Agor ffenestr newydd (%S)
+
+# New Tab button tooltip
+# LOCALIZATION NOTE (newTabButton.tooltip):
+# %S is the keyboard shortcut for "New Tab"
+newTabButton.tooltip=Agor tab newydd (%S)
+newTabContainer.tooltip=Agorwch dab newydd (%S)\nPwyso a'i ddal i agor tab cynhwysydd newydd
+newTabAlwaysContainer.tooltip=Dewiswch gynhwysydd i agor tab newydd
+
+# Offline web applications
+offlineApps.available3=Caniatáu i %S gadw data ar eich cyfrifiadur?
+offlineApps.allow.label=Caniatáu
+offlineApps.allow.accesskey=C
+offlineApps.block.label=Rhwystro
+offlineApps.block.accesskey=R
+
+# Canvas permission prompt
+# LOCALIZATION NOTE (canvas.siteprompt2): %S is hostname
+canvas.siteprompt2=Caniatáu i %S ddefnyddio'ch data delwedd cynfas HTML5?
+canvas.siteprompt2.warning=Gall hyn gael ei ddefnyddio i adnabod unigrywedd eich cyfrifiadur.
+canvas.block=Rhwystro
+canvas.block.accesskey=R
+canvas.allow2=Caniatáu
+canvas.allow2.accesskey=C
+canvas.remember2=Cofio'r penderfyniad yma
+
+# WebAuthn prompts
+# LOCALIZATION NOTE (webauthn.registerPrompt2): %S is hostname
+webauthn.registerPrompt2=Mae %S eisiau cofrestru cyfrif gyda un o'ch allweddi diogelwch. Gallwch gysylltu ac awdurdodi un nawr neu ddileu.
+# LOCALIZATION NOTE (webauthn.CTAP2registerPrompt): %S is hostname
+webauthn.CTAP2registerPrompt=Mae %S am gofrestru cyfrif gydag un o'ch allweddi diogelwch. Gallwch gysylltu un nawr neu ddiddymu.
+# LOCALIZATION NOTE (webauthn.registerTouchDevice): %S is hostname
+webauthn.registerTouchDevice=Mae %S eisiau cofrestru cyfrif gyda'ch allwedd ddiogelwch. Gallwch awdurdodi nawr neu ddiddymu.
+# LOCALIZATION NOTE (webauthn.registerDirectPrompt3):
+# %S is hostname.
+# The website is asking for extended information about your
+# hardware authenticator that shouldn't be generally necessary. Permitting
+# this is safe if you only use one account at this website. If you have
+# multiple accounts at this website, and you use the same hardware
+# authenticator, then the website could link those accounts together.
+# And this is true even if you use a different profile / browser (or even Tor
+# Browser). To avoid this, you should use different hardware authenticators
+# for different accounts on this website.
+webauthn.registerDirectPrompt3=Mae %S yn gofyn am wybodaeth estynedig am eich allwedd ddiogelwch, a allai effeithio ar eich preifatrwydd.
+# LOCALIZATION NOTE (webauthn.registerDirectPromptHint):
+# %S is brandShortName
+webauthn.registerDirectPromptHint=Gall %S guddio'ch enw ar eich rhan, ond gallai'r wefan wrthod yr allwedd hon. Os gwrthodwyd, gallwch geisio eto.
+# LOCALIZATION NOTE (webauthn.CTAP2signPrompt): %S is hostname
+webauthn.CTAP2signPrompt=Mae %S am eich dilysu gan ddefnyddio allwedd ddiogelwch gofrestredig. Gallwch gysylltu un nawr neu ddiddymu.
+# LOCALIZATION NOTE (webauthn.signTouchDevice): %S is hostname
+webauthn.signTouchDevice=Mae %S eisiau eich dilysu gan ddefnyddio'ch allwedd ddiogelwch. Gallwch awdurdodi nawr neu ddiddymu.
+# LOCALIZATION NOTE (webauthn.signPrompt2): %S is hostname
+webauthn.signPrompt2=Mae %S eisiau eich dilysu gan ddefnyddio allwedd diogelwch cofrestredig. Gallwch gysylltu a dilysu un nawr, neu ddiddymu.
+# LOCALIZATION NOTE (webauthn.selectSignResultPrompt): %S is hostname
+webauthn.selectSignResultPrompt=Wedi canfod cyfrifon lluosog ar gyfer %S. Dewiswch pa un i'w ddefnyddio neu ei ddiddymu.
+# LOCALIZATION NOTE (webauthn.selectDevicePrompt): %S is hostname
+webauthn.selectDevicePrompt=Wedi canfod dyfeisiau lluosog ar gyfer %S. Dewiswch un, os gwelwch yn dda.
+# LOCALIZATION NOTE (webauthn.deviceBlockedPrompt): %S is hostname
+webauthn.deviceBlockedPrompt=Methodd dilysu defnyddiwr ar %S. Does dim ceisiadau ar ôl ac mae'ch dyfais wedi'i chloi, oherwydd darparwyd y PIN anghywir yn rhy aml. Mae angen ailosodiad ar y ddyfais.
+# LOCALIZATION NOTE (webauthn.pinAuthBlockedPrompt): %S is hostname
+webauthn.pinAuthBlockedPrompt=Methodd dilysu defnyddiwr ar %S. Bu gormod o geisiadau aflwyddiannus ac mae dilysu PIN wedi'i rwystro dros dro. Mae angen cylchred pŵer ar eich dyfais (dad-blygio ac ail-osod).
+webauthn.cancel=Diddymu
+webauthn.cancel.accesskey=d
+webauthn.proceed=Ymlaen
+webauthn.proceed.accesskey=Y
+webauthn.anonymize=Gwneud yn anhysbys
+
+# Spoof Accept-Language prompt
+privacy.spoof_english=O bosib gall newid eich gosodiad i'r iaith Saesneg eich gwneud yn fwy anodd i'ch adnabod a gwella eich preifatrwydd. Hoffech chi wneud cais am fersiynau Saesneg o dudalennau gwe?
+
+# LOCALIZATION NOTE (identity.identified.verifier, identity.identified.state_and_country, identity.ev.contentOwner2):
+# %S is the hostname of the site that is being displayed.
+identity.identified.verifier=Dilyswyd gan: %S
+identity.identified.verified_by_you=Rydych wedi ychwanegu eithriad diogelwch ar gyfer y wefan hon.
+identity.identified.state_and_country=%S, %S
+identity.ev.contentOwner2=Tystysgrif wedi'i ryddhau i: %S
+
+# LOCALIZATION NOTE (identity.notSecure.label):
+# Keep this string as short as possible, this is displayed in the URL bar
+# use a synonym for "safe" or "private" if "secure" is too long.
+identity.notSecure.label=Dim yn Ddiogel
+identity.notSecure.tooltip=Nid yw'r cysylltiad yn ddiogel
+
+identity.extension.label=Estyniad (%S)
+identity.extension.tooltip=Llwythwyd gan estyniad: %S
+
+# LOCALIZATION NOTE (contentBlocking.trackersView.blocked.label):
+#   This label is shown next to a tracker in the trackers subview.
+#   It forms the end of the (imaginary) sentence "www.example.com [was] Blocked"
+contentBlocking.trackersView.blocked.label=Rhwystrwyd
+
+contentBlocking.trackersView.empty.label=Dim wedi eu canfod ar y wefan hon
+
+# LOCALIZATION NOTE (contentBlocking.cookies.blockingTrackers.label, contentBlocking.cookies.blocking3rdParty.label,
+#   contentBlocking.cookies.blockingUnvisited.label,contentBlocking.cookies.blockingAll.label):
+contentBlocking.cookies.blockingTrackers3.label=Cwcis Tracio Traws-Gwefan
+contentBlocking.cookies.blocking3rdParty2.label=Cwcis Trydydd Parti
+contentBlocking.cookies.blockingUnvisited2.label=Cwcis Gwefan Heb Ymweliad
+contentBlocking.cookies.blockingAll2.label=Pob Cwci
+
+contentBlocking.cookiesView.firstParty.label=O'r Wefan Hon
+# LOCALIZATION NOTE (contentBlocking.cookiesView.firstParty.empty.label):
+#  This references the header from contentBlocking.cookiesView.firstParty.label:
+#  "[Cookies] From This Site: None detected on this site".
+contentBlocking.cookiesView.firstParty.empty.label=Dim wedi eu canfod ar y wefan hon
+
+contentBlocking.cookiesView.trackers2.label=Cwcis Tracio Traws-Gwefan
+# LOCALIZATION NOTE (contentBlocking.cookiesView.trackers.empty.label):
+#  This references the header from contentBlocking.cookiesView.trackers.label:
+#  "Tracking Cookies: None detected on this site".
+contentBlocking.cookiesView.trackers.empty.label=Dim wedi eu canfod ar y wefan hon
+
+contentBlocking.cookiesView.thirdParty.label=Cwcis Trydydd Parti
+# LOCALIZATION NOTE (contentBlocking.cookiesView.thirdParty.empty.label):
+#  This references the header from contentBlocking.cookiesView.thirdParty.label:
+#  "Third-Party Cookies: None detected on this site".
+contentBlocking.cookiesView.thirdParty.empty.label=Dim wedi eu canfod ar y wefan hon
+
+# LOCALIZATION NOTE (contentBlocking.cookiesView.allowed.label):
+#   This label is shown next to a cookie origin in the cookies subview.
+#   It forms the end of the (imaginary) sentence "www.example.com [was] Allowed"
+contentBlocking.cookiesView.allowed.label=Caniatawyd
+# LOCALIZATION NOTE (contentBlocking.cookiesView.blocked.label):
+#   This label is shown next to a cookie origin in the cookies subview.
+#   It forms the end of the (imaginary) sentence "www.example.com [was] Blocked"
+contentBlocking.cookiesView.blocked.label=Rhwystrwyd
+# LOCALIZATION NOTE (contentBlocking.cookiesView.removeButton.tooltip): %S is the domain of the site.
+contentBlocking.cookiesView.removeButton.tooltip=Clirio eithriad cwci heblaw %S
+
+# LOCALIZATION NOTE (contentBlocking.fingerprintersView.blocked.label):
+#   This label is shown next to a fingerprinter in the fingerprinters subview.
+#   It forms the end of the (imaginary) sentence "www.example.com [was] Blocked"
+contentBlocking.fingerprintersView.blocked.label=Rhwystrwyd
+
+# LOCALIZATION NOTE (contentBlocking.cryptominersView.blocked.label):
+#   This label is shown next to a cryptominer in the cryptominers subview.
+#   It forms the end of the (imaginary) sentence "www.example.com [was] Blocked"
+contentBlocking.cryptominersView.blocked.label=Rhwystrwyd
+
+trackingProtection.icon.activeTooltip2=Rhwystro tracwyr cyfryngau cymdeithasol, cwcis tracio ar draws-gwefannau, a bysbrintwyr.
+trackingProtection.icon.disabledTooltip2=Mae Diogelwch Uwch Rhag Tracio I FFWRDD ar y wefan hon.
+# LOCALIZATION NOTE (trackingProtection.icon.noTrackersDetectedTooltip): %S is brandShortName.
+trackingProtection.icon.noTrackersDetectedTooltip=Dim tracwyr hysbys i %S wedi eu canfod ar y dudalen hon.
+
+# LOCALIZATION NOTE (protections.header):
+# Header of the Protections Panel. %S is replaced with the site's hostname.
+protections.header=Diogelwch ar %S
+
+# LOCALIZATION NOTE (protections.disableAriaLabel):
+# Text that gets spoken by a screen reader if the button will disable protections.
+# %s is the site's hostname.
+protections.disableAriaLabel=Analluogi diogelu ar gyfer %S
+
+# LOCALIZATION NOTE (protections.enableAriaLabel):
+# Text that gets spoken by a screen reader if the button will enable protections.
+# %s is the site's hostname.
+protections.enableAriaLabel=Galluogi diogelu ar gyfer %S
+
+# Blocking and Not Blocking sub-views in the Protections Panel
+protections.blocking.fingerprinters.title=Bysbrintwyr wedi'u rhwystro
+protections.blocking.cryptominers.title=Cryptogloddwyr wedi'u Rhwystro
+protections.blocking.cookies.trackers.title=Cwcis Tracio Traws-Gwefan wedi'u Rhwystro
+protections.blocking.cookies.3rdParty.title=Cwcis Trydydd Parti wedi'u Rhwystro
+protections.blocking.cookies.all.title=Pob Cwci wedi eu Rhwystro
+protections.blocking.cookies.unvisited.title=Cwcis Gwefan Heb Ymweliad wedi'u Rhwystro
+protections.blocking.trackingContent.title=Cynnwys Tracio wedi'u Rhwystro
+protections.blocking.socialMediaTrackers.title=Tracwyr Cyfryngau Cymdeithasol wedi'u Rhwystro
+protections.notBlocking.fingerprinters.title=Ddim yn Rhwystro Bysbrintwyr
+protections.notBlocking.cryptominers.title=Ddim yn Rhwystro Cryptogloddwyr
+protections.notBlocking.cookies.3rdParty.title=Ddim Yn Rhwystro Cwcis Trydydd Parti
+protections.notBlocking.cookies.all.title=Ddim yn Rhwystro Cwcis
+protections.notBlocking.crossSiteTrackingCookies.title=Ddim yn Rhwystro Cwcis Tracio Traws Gwefan
+protections.notBlocking.trackingContent.title=Ddim yn Rhwystro Cynnwys Tracio
+protections.notBlocking.socialMediaTrackers.title=Ddim yn Rhwystro Tracwyr Cyfryngau Cymdeithasol
+
+# Footer section in the Protections Panel
+# LOCALIZATION NOTE (protections.footer.blockedTrackerCounter.description,
+# protections.footer.blockedTrackerCounter.tooltip):
+#   This text indicates the total number of trackers blocked on all sites. In
+#   its tooltip, we show the date when we started counting this number.
+# LOCALIZATION NOTE (protections.footer.blockedTrackerCounter.description):
+#   Semicolon-separated list of plural forms.
+#   See: http://developer.mozilla.org/en/docs/Localization_and_Plurals
+#   Replacement for #1 is a locale-string converted positive integer.
+protections.footer.blockedTrackerCounter.description=1 Wedi'u Rhwystro;#1 Wedi'i Rwystro;#1 Wedi'u Rhwystro;#1 Wedi'u Rhwystro;#1 Wedi'u Rhwystro;#1 Wedi'u Rhwystro
+# LOCALIZATION NOTE (protections.footer.blockedTrackerCounter.tooltip):
+#   %S is the date on which we started counting (e.g., July 17, 2019).
+protections.footer.blockedTrackerCounter.tooltip=Ers %S
+
+# Milestones section in the Protections Panel
+# LOCALIZATION NOTE (protections.milestone.description):
+#   Semicolon-separated list of plural forms.
+#   See: http://developer.mozilla.org/en/docs/Localization_and_Plurals
+#   #1 is replaced with brandShortName.
+#   #2 is replaced with the (locale-formatted) number of trackers blocked
+#   #3 is replaced by a locale-formatted date with short month and numeric year.
+#   In English this looks like "Firefox blocked over 10,000 trackers since Oct 2019"
+protections.milestone.description=Mae #1 wedi rhwystro #2 traciwr ers #3;Mae #1 wedi rhwystro #2 traciwr ers #3;Mae #1 wedi rhwystro #2 draciwr ers #3;Mae #1 wedi rhwystro #2 traciwr ers #3;Mae #1 wedi rhwystro #2 traciwr ers #3;Mae #1 wedi rhwystro #2 traciwr ers #3
+
+# Application menu
+
+# LOCALIZATION NOTE(zoomReduce-button.tooltip): %S is the keyboard shortcut.
+zoomReduce-button.tooltip = Chwyddo allan (%S)
+# LOCALIZATION NOTE(zoomReset-button.tooltip): %S is the keyboard shortcut.
+zoomReset-button.tooltip = Ailosod lefel chwyddo (%S)
+# LOCALIZATION NOTE(zoomEnlarge-button.tooltip): %S is the keyboard shortcut.
+zoomEnlarge-button.tooltip = Chwyddo i mewn (%S)
+
+# LOCALIZATION NOTE (cut-button.tooltip): %S is the keyboard shortcut.
+cut-button.tooltip = Torri (%S)
+# LOCALIZATION NOTE (copy-button.tooltip): %S is the keyboard shortcut.
+copy-button.tooltip = Copïo (%S)
+# LOCALIZATION NOTE (paste-button.tooltip): %S is the keyboard shortcut.
+paste-button.tooltip = Gludo (%S)
+
+# Geolocation UI
+
+geolocation.allow=Caniatáu
+geolocation.allow.accesskey=C
+geolocation.block=Rhwystro
+geolocation.block.accesskey=R
+geolocation.shareWithSite4=Caniatáu i %S gael mynediad i'ch lleoliad?
+geolocation.shareWithFile4=Caniatáu i'r ffeil leol hon gael mynediad i'ch lleoliad?
+# LOCALIZATION NOTE(geolocation.shareWithSiteUnsafeDelegation2):
+# %1$S is the first party origin, %2$S is the third party origin.
+geolocation.shareWithSiteUnsafeDelegation2=Caniatáu i %1$S roi caniatâd i %2$S gael mynediad i'ch lleoliad?
+geolocation.remember=Cofio'r penderfyniad yma
+
+# Virtual Reality Device UI
+xr.allow2=Caniatáu
+xr.allow2.accesskey=C
+xr.block=Rhwystro
+xr.block.accesskey=R
+xr.shareWithSite4=Caniatáu i %S gael mynediad at ddyfeisiau rhithrealaeth? Gall hyn ddatgelu gwybodaeth sensitif.
+xr.shareWithFile4=Caniatáu i %S gael mynediad at ddyfeisiau rhithrealaeth? Gall hyn ddatgelu gwybodaeth sensitif.
+xr.remember=Cofio'r penderfyniad yma
+
+# Persistent storage UI
+persistentStorage.allow=Caniatáu
+persistentStorage.allow.accesskey=C
+persistentStorage.block.label=Rhwystro
+persistentStorage.block.accesskey=R
+persistentStorage.allowWithSite2=Caniatáu i %S storio data mewn storfa barhaus?
+
+# Web notifications UI
+# LOCALIZATION NOTE (alwaysBlock, block)
+# The two button strings will never be shown at the same time, so
+# it's okay for them to have the same access key
+webNotifications.allow2=Caniatáu
+webNotifications.allow2.accesskey=C
+webNotifications.notNow=Nid Nawr
+webNotifications.notNow.accesskey=n
+webNotifications.never=Byth Caniatáu
+webNotifications.never.accesskey=b
+webNotifications.alwaysBlock=Rhwystro Bob Tro
+webNotifications.alwaysBlock.accesskey=R
+webNotifications.block=Rhwystro
+webNotifications.block.accesskey=R
+webNotifications.receiveFromSite3=Caniatáu i %S anfon hysbysiadau?
+
+# Phishing/Malware Notification Bar.
+# LOCALIZATION NOTE (notADeceptiveSite, notAnAttack)
+# The two button strings will never be shown at the same time, so
+# it's okay for them to have the same access key
+safebrowsing.getMeOutOfHereButton.label=Allan o fan hyn!
+safebrowsing.getMeOutOfHereButton.accessKey=A
+safebrowsing.deceptiveSite=Gwefan Twyllodrus!
+safebrowsing.notADeceptiveSiteButton.label=Nid yw hon yn wefan twyllodrus…
+safebrowsing.notADeceptiveSiteButton.accessKey=t
+safebrowsing.reportedAttackSite=Gwefan Ymosod Hysbys!
+safebrowsing.notAnAttackButton.label=Nid gwefan ymosodiad yw hwn…
+safebrowsing.notAnAttackButton.accessKey=y
+safebrowsing.reportedUnwantedSite=Gwefan Meddalwedd Digroeso Hysbys!
+safebrowsing.reportedHarmfulSite=Gwefan Niweidiol Hysbys!
+
+# Ctrl-Tab
+# LOCALIZATION NOTE (ctrlTab.listAllTabs.label): #1 represents the number
+# of tabs in the current browser window. It will always be 2 at least.
+# See: http://developer.mozilla.org/en/docs/Localization_and_Plurals
+ctrlTab.listAllTabs.label=Rhestru Dim Tabiau;Rhestru pob un o'r #1 Tab;Rhestru Pob un o'r #1 Dab;Rhestru Pob un o'r #1 Thab;Rhestru Pob un o'r #1 Tab;Rhestru Pob un o'r #1 Tab
+
+# LOCALIZATION NOTE (addKeywordTitleAutoFill): %S will be replaced by the page's title
+# Used as the bookmark name when saving a keyword for a search field.
+addKeywordTitleAutoFill=Chwilio %S
+
+# troubleshootModeRestart
+# LOCALIZATION NOTE (troubleshootModeRestartPromptTitle): %S is the name of the product (e.g., Firefox)
+troubleshootModeRestartPromptTitle=Ailgychwyn %S yn y Modd Datrys Problemau?
+troubleshootModeRestartPromptMessage=Bydd eich ychwanegion a'ch gosodiadau cyfaddas yn cael eu hanalluogi dros dro.
+troubleshootModeRestartButton=Ailgychwyn
+
+# LOCALIZATION NOTE (browser.menu.showCharacterEncoding): Set to the string
+# "true" (spelled and capitalized exactly that way) to show the "Text
+# Encoding" menu in the main Firefox button on Windows. Any other value will
+# hide it. Regardless of the value of this setting, the "Text Encoding"
+# menu will always be accessible via the "Browser Tools" menu.
+# This is not a string to translate; it just controls whether the menu shows
+# up in the Firefox button. If users frequently use the "Text Encoding"
+# menu, set this to "true". Otherwise, you can leave it as "false".
+browser.menu.showCharacterEncoding=false
+
+# Process hang reporter
+# LOCALIZATION NOTE (processHang.selected_tab.label): %1$S is the name of the product (e.g., Firefox)
+processHang.selected_tab.label = Mae'r dudalen hon yn arafu %1$S. I gyflymu'ch porwr, stopiwch y dudalen hon.
+# LOCALIZATION NOTE (processHang.nonspecific_tab.label): %1$S is the name of the product (e.g., Firefox)
+processHang.nonspecific_tab.label = Mae tudalen gwe'n arafu %1$S. I gyflymu'ch porwr, stopiwch y dudalen honno.
+# LOCALIZATION NOTE (processHang.specific_tab.label): %1$S is the title of the tab.
+# %2$S is the name of the product (e.g., Firefox)
+processHang.specific_tab.label = Mae “%1$S” yn arafu %2$S. I gyflymu'ch porwr, stopiwch y dudalen honno.
+# LOCALIZATION NOTE (processHang.add-on.label2): %1$S is the name of the
+# extension. %2$S is the name of the product (e.g., Firefox)
+processHang.add-on.label2 = Mae “%1$S” yn arafu %2$S. I gyflymu'ch porwr, stopiwch yr estyniad hwnnw.
+processHang.add-on.learn-more.text = Dysgu rhagor
+processHang.button_stop2.label = Atal
+processHang.button_stop2.accessKey = A
+processHang.button_debug.label = Sgript Dadfygio
+processHang.button_debug.accessKey = S
+
+# LOCALIZATION NOTE (fullscreenButton.tooltip): %S is the keyboard shortcut for full screen
+fullscreenButton.tooltip=Dangos y ffenestr yn y sgrin lawn (%S)
+
+# These are visible when opening the popup inside the bookmarks sidebar
+sidebar.moveToLeft=Symud y Bar Ochr i'r Chwith
+sidebar.moveToRight=Symud y Bar Ochr i'r Dde
+
+# LOCALIZATION NOTE (getUserMedia.shareCamera3.message,
+#                    getUserMedia.shareMicrophone3.message,
+#                    getUserMedia.shareScreen4.message,
+#                    getUserMedia.shareCameraAndMicrophone3.message,
+#                    getUserMedia.shareCameraAndAudioCapture3.message,
+#                    getUserMedia.shareScreenAndMicrophone4.message,
+#                    getUserMedia.shareScreenAndAudioCapture4.message,
+#                    getUserMedia.shareAudioCapture3.message):
+# %S is the website origin (e.g. www.mozilla.org)
+getUserMedia.shareCamera3.message = Caniatáu i %S ddefnyddio’ch camera?
+getUserMedia.shareMicrophone3.message = Caniatáu i %S ddefnyddio’ch meicroffon?
+getUserMedia.shareScreen4.message = Caniatáu i %S weld eich sgrin?
+getUserMedia.shareCameraAndMicrophone3.message = Caniatáu i %S ddefnyddio'ch camera a'ch meicroffon?
+getUserMedia.shareCameraAndAudioCapture3.message = Caniatáu i %S ddefnyddio'ch camera a gwrando ar sain y tab hwn?
+getUserMedia.shareScreenAndMicrophone4.message = Caniatáu i %S ddefnyddio'ch meicroffon a gweld eich sgrin?
+getUserMedia.shareScreenAndAudioCapture4.message = Caniatáu i %S wrando ar sain y tab hwn a gweld eich sgrin?
+getUserMedia.shareAudioCapture3.message = Caniatáu i %S wrando ar sain y tab hwn?
+# LOCALIZATION NOTE (selectAudioOutput.shareSpeaker.message):
+# "Speakers" is used in a general sense that might include headphones or
+# another audio output connection.
+# %S is the website origin (e.g. www.mozilla.org)
+selectAudioOutput.shareSpeaker.message = Caniatáu i %S ddefnyddio seinyddion eraill?
+
+# LOCALIZATION NOTE (getUserMedia.shareCameraUnsafeDelegation2.message,
+#                    getUserMedia.shareMicrophoneUnsafeDelegation2.message,
+#                    getUserMedia.shareScreenUnsafeDelegation2.message,
+#                    getUserMedia.shareCameraAndMicrophoneUnsafeDelegation2.message,
+#                    getUserMedia.shareCameraAndAudioCaptureUnsafeDelegation2.message,
+#                    getUserMedia.shareScreenAndMicrophoneUnsafeDelegation2.message,
+#                    getUserMedia.shareScreenAndAudioCaptureUnsafeDelegation2.message,
+# %1$S is the first party origin.
+# %2$S is the third party origin.
+getUserMedia.shareCameraUnsafeDelegation2.message = Caniatáu i %1$S roi mynediad i %2$S at eich camera?
+getUserMedia.shareMicrophoneUnsafeDelegations2.message = Caniatáu i %1$S roi mynediad i %2$S i'ch meicroffon?
+getUserMedia.shareScreenUnsafeDelegation2.message = Caniatáu i %1$S roi caniatâd i %2$S weld eich sgrin?
+getUserMedia.shareCameraAndMicrophoneUnsafeDelegation2.message = Caniatáu i %1$S roi mynediad i %2$S i'ch camera a'ch meicroffon?
+getUserMedia.shareCameraAndAudioCaptureUnsafeDelegation2.message = Caniatáu i %1$S roi mynediad i %2$S at eich camera a gwrando ar sain y tab hwn?
+getUserMedia.shareScreenAndMicrophoneUnsafeDelegation2.message = Caniatáu i %1$S roi mynediad i %2$S i'ch meicroffon a gweld eich sgrin?
+getUserMedia.shareScreenAndAudioCaptureUnsafeDelegation2.message = Caniatáu i %1$S roi caniatâd i %2$S wrando ar sain y tab hwn a gweld eich sgrin?
+# LOCALIZATION NOTE ():
+# "Speakers" is used in a general sense that might include headphones or
+# another audio output connection.
+# %1$S is the first party origin.
+# %2$S is the third party origin.
+selectAudioOutput.shareSpeakerUnsafeDelegation.message = Caniatáu i %1$S roi mynediad  i %2$S i seinyddion eraill?
+
+# LOCALIZATION NOTE (getUserMedia.shareScreenWarning.message): NB: inserted via innerHTML, so please don't use <, > or & in this string.
+getUserMedia.shareScreenWarning2.message = Rhannwch dim ond sgriniau â gwefannau rydych chi'n ymddiried ynddyn nhw. Gall rhannu ganiatáu i wefannau twyllodrus bori fel taw chi sydd wrthi a dwyn eich data preifat.
+# LOCALIZATION NOTE (getUserMedia.shareFirefoxWarning.message): NB: inserted via innerHTML, so please don't use <, > or & in this string.
+# %S is brandShortName (eg. Firefox)
+getUserMedia.shareFirefoxWarning2.message = Rhannwch %S dim ond gyda gwefannau rydych yn ymddiried ynddyn nhw. Gall rhannu ganiatáu i wefannau twyllodrus bori fel taw chi sydd wrthi a dwyn eich data preifat.
+# LOCALIZATION NOTE(getUserMedia.shareScreen.learnMoreLabel): NB: inserted via innerHTML, so please don't use <, > or & in this string.
+getUserMedia.shareScreen.learnMoreLabel = Dysgu Rhagor
+getUserMedia.selectWindowOrScreen2.label = Ffenestr neu sgrin:
+getUserMedia.selectWindowOrScreen2.accesskey = F
+getUserMedia.pickWindowOrScreen.label = Dewiswch Ffenestr neu Sgrin
+getUserMedia.shareEntireScreen.label = Sgrin gyfan
+getUserMedia.sharePipeWirePortal.label = Defnyddio gosodiadau'r system weithredu
+# LOCALIZATION NOTE (getUserMedia.shareMonitor.label):
+# %S is screen number (digits 1, 2, etc)
+# Example: Screen 1, Screen 2,..
+getUserMedia.shareMonitor.label = Sgrin %S
+# LOCALIZATION NOTE (getUserMedia.shareApplicationWindowCount.label):
+# Semicolon-separated list of plural forms.
+# See: http://developer.mozilla.org/en/docs/Localization_and_Plurals
+# Replacement for #1 is the name of the application.
+# Replacement for #2 is the number of windows currently displayed by the application.
+getUserMedia.shareApplicationWindowCount.label=#1 (Dim ffenestri);#1 (#2 ffenestr);#1 (#2 ffenestr);#1 (#2 ffenestr);#1 (#2 ffenestr);#1 (#2 ffenestr)
+# LOCALIZATION NOTE (getUserMedia.allow.label,
+#                    getUserMedia.block.label):
+# These two buttons are the possible answers to the various prompts in the
+# "getUserMedia.share{device}.message" strings.
+getUserMedia.allow.label = Caniatáu
+getUserMedia.allow.accesskey = C
+getUserMedia.block.label = Rhwystro
+getUserMedia.block.accesskey = R
+getUserMedia.remember=Cofio'r penderfyniad yma
+# LOCALIZATION NOTE (getUserMedia.reasonForNoPermanentAllow.screen3,
+#                    getUserMedia.reasonForNoPermanentAllow.audio,
+#                    getUserMedia.reasonForNoPermanentAllow.insecure):
+# %S is brandShortName
+getUserMedia.reasonForNoPermanentAllow.screen3=Nid yw %S yn caniatáu mynediad parhaus i'ch sgrin.
+getUserMedia.reasonForNoPermanentAllow.audio=Nid yw %S yn gallu caniatáu mynediad parhaol i sain eich tab heb ofyn pa dab i'w rannu.
+getUserMedia.reasonForNoPermanentAllow.insecure=Nid yw eich cysylltiad a'r wefan hon y ddiogel. Er mwyn eich diogelu, dim ond ar gyfer y sesiwn yma y bydd %S yn caniatáu mynediad.
+
+getUserMedia.sharingMenu.label = Tabiau dyfeisiau sy'n rhannu
+getUserMedia.sharingMenu.accesskey = d
+# LOCALIZATION NOTE (getUserMedia.sharingMenuCamera
+#                    getUserMedia.sharingMenuMicrophone,
+#                    getUserMedia.sharingMenuAudioCapture,
+#                    getUserMedia.sharingMenuApplication,
+#                    getUserMedia.sharingMenuScreen,
+#                    getUserMedia.sharingMenuWindow,
+#                    getUserMedia.sharingMenuBrowser,
+#                    getUserMedia.sharingMenuCameraMicrophone,
+#                    getUserMedia.sharingMenuCameraMicrophoneApplication,
+#                    getUserMedia.sharingMenuCameraMicrophoneScreen,
+#                    getUserMedia.sharingMenuCameraMicrophoneWindow,
+#                    getUserMedia.sharingMenuCameraMicrophoneBrowser,
+#                    getUserMedia.sharingMenuCameraAudioCapture,
+#                    getUserMedia.sharingMenuCameraAudioCaptureApplication,
+#                    getUserMedia.sharingMenuCameraAudioCaptureScreen,
+#                    getUserMedia.sharingMenuCameraAudioCaptureWindow,
+#                    getUserMedia.sharingMenuCameraAudioCaptureBrowser,
+#                    getUserMedia.sharingMenuCameraApplication,
+#                    getUserMedia.sharingMenuCameraScreen,
+#                    getUserMedia.sharingMenuCameraWindow,
+#                    getUserMedia.sharingMenuCameraBrowser,
+#                    getUserMedia.sharingMenuMicrophoneApplication,
+#                    getUserMedia.sharingMenuMicrophoneScreen,
+#                    getUserMedia.sharingMenuMicrophoneWindow,
+#                    getUserMedia.sharingMenuMicrophoneBrowser,
+#                    getUserMedia.sharingMenuAudioCaptureApplication,
+#                    getUserMedia.sharingMenuAudioCaptureScreen,
+#                    getUserMedia.sharingMenuAudioCaptureWindow,
+#                    getUserMedia.sharingMenuAudioCaptureBrowser):
+# %S is the website origin (e.g. www.mozilla.org)
+getUserMedia.sharingMenuCamera = %S (camera)
+getUserMedia.sharingMenuMicrophone = %S (meicroffon)
+getUserMedia.sharingMenuAudioCapture = %S (tab sain)
+getUserMedia.sharingMenuApplication = %S (rhaglen)
+getUserMedia.sharingMenuScreen = %S (sgrin)
+getUserMedia.sharingMenuWindow = %S (ffenestr)
+getUserMedia.sharingMenuBrowser = %S (tab)
+getUserMedia.sharingMenuCameraMicrophone = %S (camera a meicroffon)
+getUserMedia.sharingMenuCameraMicrophoneApplication = %S (camera, meicroffon a rhaglen)
+getUserMedia.sharingMenuCameraMicrophoneScreen = %S (camera, meicroffon a sgrin)
+getUserMedia.sharingMenuCameraMicrophoneWindow = %S (camera, meicroffon a ffenestr)
+getUserMedia.sharingMenuCameraMicrophoneBrowser = %S (camera, meicroffon a thab)
+getUserMedia.sharingMenuCameraAudioCapture = %S (camera a thab sain)
+getUserMedia.sharingMenuCameraAudioCaptureApplication = %S (camera, tab sain a rhaglen)
+getUserMedia.sharingMenuCameraAudioCaptureScreen = %S (camera, tab sain a sgrin)
+getUserMedia.sharingMenuCameraAudioCaptureWindow = %S (camera, tab sain a ffenestr)
+getUserMedia.sharingMenuCameraAudioCaptureBrowser = %S (camera, tab sain a thab)
+getUserMedia.sharingMenuCameraApplication = %S (camera a rhaglen)
+getUserMedia.sharingMenuCameraScreen = %S (camera a sgrin)
+getUserMedia.sharingMenuCameraWindow = %S (camera a ffenestr)
+getUserMedia.sharingMenuCameraBrowser = %S (camera a thab)
+getUserMedia.sharingMenuMicrophoneApplication = %S (meicroffon a rhaglen)
+getUserMedia.sharingMenuMicrophoneScreen = %S (meicroffon a sgrin)
+getUserMedia.sharingMenuMicrophoneWindow = %S (meicroffon a ffenestr)
+getUserMedia.sharingMenuMicrophoneBrowser = %S (meicroffon a thab)
+getUserMedia.sharingMenuAudioCaptureApplication = %S (tab sain a rhaglen)
+getUserMedia.sharingMenuAudioCaptureScreen = %S (tab sain a sgrin)
+getUserMedia.sharingMenuAudioCaptureWindow = %S (tab sain a ffenestr)
+getUserMedia.sharingMenuAudioCaptureBrowser = %S (tab sain a thab)
+# LOCALIZATION NOTE(getUserMedia.sharingMenuUnknownHost): this is used for the website
+# origin for the sharing menu if no readable origin could be deduced from the URL.
+getUserMedia.sharingMenuUnknownHost = Tarddiad anhysbys
+
+# LOCALIZATION NOTE(emeNotifications.drmContentDisabled.message): NB: inserted via innerHTML, so please don't use <, > or & in this string. %S will be the 'learn more' link
+emeNotifications.drmContentDisabled.message2 = Rhaid galluogi DRM i chwarae'r sain neu'r fideo sydd ar y dudalen hon. %S
+emeNotifications.drmContentDisabled.button.label = Galluogi DRM
+emeNotifications.drmContentDisabled.button.accesskey = G
+
+# LOCALIZATION NOTE(emeNotifications.drmContentCDMInstalling.message): NB: inserted via innerHTML, so please don't use <, > or & in this string. %S is brandShortName
+emeNotifications.drmContentCDMInstalling.message = Mae %S yn gosod cydrannau sydd eu hangen i chwarae'r sain a'r fideo ar y dudalen hon. Ceisiwch eto'n hwyrach ymlaen.
+
+emeNotifications.unknownDRMSoftware = Anhysbys
+
+# LOCALIZATION NOTE (customizeMode.tabTitle): %S is brandShortName
+customizeMode.tabTitle = Cyfaddasu %S
+
+e10s.accessibilityNotice.acceptButton.label = Iawn
+e10s.accessibilityNotice.acceptButton.accesskey = I
+
+# LOCALIZATION NOTE (e10s.accessibilityNotice.jawsMessage): %S is brandShortName
+e10s.accessibilityNotice.jawsMessage = Mae dangos cynnwys tabiau wedi ei analluogi oherwydd anghydnawsedd rhwng %S â'ch meddalwedd hygyrchedd. Diweddarwch eich darllenydd sgrin neu newidiwch i Firefox Extended Support Release.
+
+# LOCALIZATION NOTE (userContextPersonal.label,
+#                    userContextWork.label,
+#                    userContextShopping.label,
+#                    userContextBanking.label,
+#                    userContextNone.label):
+# These strings specify the four predefined contexts included in support of the
+# Contextual Identity / Containers project. Each context is meant to represent
+# the context that the user is in when interacting with the site. Different
+# contexts will store cookies and other information from those sites in
+# different, isolated locations. You can enable the feature by typing
+# about:config in the URL bar and changing privacy.userContext.enabled to true.
+# Once enabled, you can open a new tab in a specific context by clicking
+# File > New Container Tab > (1 of 4 contexts). Once opened, you will see these
+# strings on the right-hand side of the URL bar.
+userContextPersonal.label = Personol
+userContextWork.label = Gwaith
+userContextBanking.label = Bancio
+userContextShopping.label = Siopa
+userContextNone.label = Dim Cynhwysydd
+
+userContextPersonal.accesskey = P
+userContextWork.accesskey = G
+userContextBanking.accesskey = B
+userContextShopping.accesskey = S
+userContextNone.accesskey = D
+
+userContext.aboutPage.label = Rheoli cynwysyddion
+userContext.aboutPage.accesskey = y
+
+muteTab.label = Tewi Tab
+muteTab.accesskey = T
+unmuteTab.label = Tab Dad-dewi
+unmuteTab.accesskey = D
+
+muteSelectedTabs2.label = Tewi Tabiau
+# LOCALIZATION NOTE (muteSelectedTabs2.accesskey): The accesskey should
+# match the accesskey for muteTab.accesskey
+muteSelectedTabs2.accesskey = T
+unmuteSelectedTabs2.label = Dad-dewi Tabiau
+# LOCALIZATION NOTE (unmuteSelectedTabs2.accesskey): The accesskey should
+# match the accesskey for unmuteTab.accesskey
+unmuteSelectedTabs2.accesskey = t
+
+# LOCALIZATION NOTE (sendTabsToDevice.label):
+# Semi-colon list of plural forms.
+# See: https://developer.mozilla.org/en/docs/Localization_and_Plurals
+# #1 is the number of tabs sent to the device.
+sendTabsToDevice.label = Anfon Tab i Ddyfais;Anfon #1 Tab i Ddyfais;Anfon #1 Dab i Ddyfais;Anfon #1 Thab i Ddyfais;Anfon #1 Tab i Ddyfais;Anfon #1 Thab i Ddyfais
+sendTabsToDevice.accesskey = n
+
+# LOCALIZATION NOTE (pendingCrashReports2.label): Semi-colon list of plural forms
+# See: http://developer.mozilla.org/en/docs/Localization_and_Plurals
+# #1 is the number of pending crash reports
+pendingCrashReports2.label = Nid oes gennych adroddiad chwalu sydd heb ei gyflwyno;Mae gennych #1 adroddiad chwalu sydd heb ei gyflwyno;Mae gennych #1 adroddiad chwalu sydd heb eu cyflwyno;Mae gennych #1 adroddiad chwalu sydd heb eu cyflwyno;Mae gennych #1 adroddiad chwalu sydd heb eu cyflwyno;Mae gennych #1 adroddiad chwalu sydd heb eu cyflwyno
+pendingCrashReports.viewAll = Gweld
+pendingCrashReports.send = Anfon
+pendingCrashReports.alwaysSend = Anfon Bob Tro
+
+decoder.noCodecs.button = Sut mae gwneud
+decoder.noCodecs.accesskey = D
+decoder.noCodecsLinux.message = I chwarae fideo, efallai y bydd angen gosod y codecsau fideo angenrheidiol.
+decoder.noHWAcceleration.message = I wella ansawdd y fideo, efallai y bydd angen gosod y Microsoft Media Feature Pack.
+decoder.noPulseAudio.message = I chwarae sain, efallai y bydd angen gosod y feddalwedd PulseAudio angenrheidiol.
+decoder.unsupportedLibavcodec.message = Gall libavcodec fod yn fregus neu heb ei gynnal a dylai gael ei ddiweddaru ar gyfer chwarae fideo.
+
+decoder.decodeError.message = Digwyddodd gwall wrth ddadgodio adnodd cyfrwng.
+decoder.decodeError.button = Adrodd ar Fater Gwefan
+decoder.decodeError.accesskey = A
+decoder.decodeWarning.message = Digwyddodd gwall adferadwy wrth ddadgodio adnodd cyfrwng.
+
+# LOCALIZATION NOTE (captivePortal.infoMessage3):
+# Shown in a notification bar when we detect a captive portal is blocking network access
+# and requires the user to log in before browsing.
+captivePortal.infoMessage3 = Rhaid i chi fewngofnodi i'r rhwydwaith hwn cyn i chi gael mynediad i'r Rhyngrwyd.
+# LOCALIZATION NOTE (captivePortal.showLoginPage2):
+# The label for a button shown in the info bar in all tabs except the login page tab.
+# The button shows the portal login page tab when clicked.
+captivePortal.showLoginPage2 = Agor Tudalen Mewngofnodi i'r Rhwydwaith
+
+# LOCALIZATION NOTE (permissions.header):
+# %S is the hostname of the site that is being displayed.
+permissions.header = Caniatâd ar gyfer: %S
+permissions.remove.tooltip = Clirio'r caniatâd a gofyn eto
+
+permissions.fullscreen.promptCanceled = Diddymu ceisiadau am ganiatâd: peidiwch cyhoeddi ceisiadau am ganiatâd cyn mynd i mewn i sgrin lawn DOM.
+permissions.fullscreen.fullScreenCanceled = Sgrin lawn DOM wedi'u Gadael: peidiwch cyhoeddi ceisiadau am ganiatâd tra ar sgrin lawn DOM.
+
+# LOCALIZATION NOTE (aboutDialog.architecture.*):
+# The sixtyFourBit and thirtyTwoBit strings describe the architecture of the
+# current Firefox build: 32-bit or 64-bit. These strings are used in parentheses
+# between the Firefox version and the "What's new" link in the About dialog,
+# e.g.: "48.0.2 (32-bit) <What's new>" or "51.0a1 (2016-09-05) (64-bit)".
+aboutDialog.architecture.sixtyFourBit = 64 did
+aboutDialog.architecture.thirtyTwoBit = 32 did
+
+midi.allow.label = Caniatáu
+midi.allow.accesskey = C
+midi.block.label = Rhwystro
+midi.block.accesskey = B
+midi.remember=Cofio'r penderfyniad yma
+midi.shareWithFile = Caniatáu i'r ffeil leol hon gael mynediad i'ch dyfais MIDI?
+# LOCALIZATION NOTE (midi.shareWithSite): %S is the name of the site URL (https://...) requesting MIDI access
+midi.shareWithSite = Caniatáu i %S gael mynediad at eich dyfeisiau MIDI?
+midi.shareSysexWithFile = Caniatáu i'r ffeil leol hon gael mynediad at eich dyfeisiau MIDI ac anfon/derbyn negeseuon SysEx?
+# LOCALIZATION NOTE (midi.shareSysexWithSite): %S is the name of the site URL (https://...) requesting MIDI access
+midi.shareSysexWithSite = Caniatáu i %S gael mynediad at eich dyfeisiau MIDI ac anfon/derbyn negeseuon SysEx?
+
+# LOCALIZATION NOTE (panel.back):
+# This is used by screen readers to label the "back" button in various browser
+# popup panels, including the sliding subviews of the main menu.
+panel.back = Nôl
+
+storageAccess1.Allow.label = Caniatáu
+storageAccess1.Allow.accesskey = C
+storageAccess1.DontAllow.label = Rhwystro
+storageAccess1.DontAllow.accesskey = R
+# LOCALIZATION NOTE (storageAccess4.message, storageAccess1.hintText):
+# %1$S is the name of the site URL (www.site1.example) trying to track the user's activity.
+# %2$S is the name of the site URL (www.site2.example) that the user is visiting.  This is the same domain name displayed in the address bar.
+storageAccess4.message = Caniatáu i %1$S ddefnyddio ei gwcis ar %2$S?
+storageAccess1.hintText = Efallai y byddwch am rwystro mynediad os nad yw'n glir pam mae angen y data hwn ar %1$S.
+
+
+
+confirmationHint.sendToDevice.label = Anfonwyd!
+confirmationHint.copyURL.label = Copïwyd i'r clipfwrdd!
+confirmationHint.pageBookmarked2.label = Wedi'i gadw i nodau tudalen
+confirmationHint.pinTab.label = Piniwyd!
+confirmationHint.pinTab.description = Rhowch glic de i'r tab i'w ddabinio.
+confirmationHint.passwordSaved.label = Cyfrinair wedi'i gadw!
+confirmationHint.loginRemoved.label = Mewngofnodi wedi'i dynnu!
+confirmationHint.breakageReport.label = Anfonwyd yr adroddiad. Diolch!
+
+# LOCALIZATION NOTE (gnomeSearchProviderSearch):
+# Used for search by Gnome Shell activity screen, %S is a searched string.
+gnomeSearchProviderSearch=Chwiliwch ar y we am %S
+
+# LOCALIZATION NOTE (gnomeSearchProviderSearchWeb):
+# Used for search by Gnome Shell activity screen, %S is a searched string.
+gnomeSearchProviderSearchWeb=Chwiliwch ar y we am “%S”
diff --git a/l10n-cy/browser/chrome/browser/customizableui/customizableWidgets.properties b/l10n-cy/browser/chrome/browser/customizableui/customizableWidgets.properties
new file mode 100644
index 0000000000..8fd580479e
--- /dev/null
+++ b/l10n-cy/browser/chrome/browser/customizableui/customizableWidgets.properties
@@ -0,0 +1,54 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+history-panelmenu.label = Hanes
+# LOCALIZATION NOTE(history-panelmenu.tooltiptext2): %S is the keyboard shortcut
+history-panelmenu.tooltiptext2 = Dangos eich hanes (%S)
+
+find-button.label = Canfod
+# LOCALIZATION NOTE(find-button.tooltiptext3): %S is the keyboard shortcut.
+find-button.tooltiptext3 = Canfod ar y dudalen (%S)
+
+developer-button.label = Datblygwr
+# LOCALIZATION NOTE(developer-button.tooltiptext): %S is the keyboard shortcut
+developer-button.tooltiptext2 = Agor offer datblygwyr Gwe (%S)
+
+sidebar-button.label = Barrau Ochr
+sidebar-button.tooltiptext2 = Dangos barau ochr
+
+zoom-controls.label = Offer Chwyddo
+zoom-controls.tooltiptext2 = Offer chwyddo
+
+zoom-out-button.label = Chwyddo allan
+# LOCALIZATION NOTE(zoom-out-button.tooltiptext2): %S is the keyboard shortcut.
+zoom-out-button.tooltiptext2 = Chwyddo allan (%S)
+
+# LOCALIZATION NOTE(zoom-reset-button.tooltiptext2): %S is the keyboard shortcut.
+zoom-reset-button.tooltiptext2 = Ailosod lefel chwyddo (%S)
+
+zoom-in-button.label = Chwyddo mewn
+# LOCALIZATION NOTE(zoom-in-button.tooltiptext2): %S is the keyboard shortcut.
+zoom-in-button.tooltiptext2 = Chwyddo i mewn (%S)
+
+edit-controls.label = Rheolyddion Golygu
+edit-controls.tooltiptext2 = Rheolyddion golygu
+
+cut-button.label = Torri
+# LOCALIZATION NOTE(cut-button.tooltiptext2): %S is the keyboard shortcut.
+cut-button.tooltiptext2 = Torri (%S)
+
+copy-button.label = Copïo
+# LOCALIZATION NOTE(copy-button.tooltiptext2): %S is the keyboard shortcut.
+copy-button.tooltiptext2 = Copïo (%S)
+
+paste-button.label = Gludo
+# LOCALIZATION NOTE(paste-button.tooltiptext2): %S is the keyboard shortcut.
+paste-button.tooltiptext2 = Gludo (%S)
+
+panic-button.label = Anghofio
+panic-button.tooltiptext = Anghofio am beth hanes pori
+
+toolbarspring.label = Bwlch Hyblyg
+toolbarseparator.label = Gwahanydd
+toolbarspacer.label = Bwlch
diff --git a/l10n-cy/browser/chrome/browser/downloads/downloads.properties b/l10n-cy/browser/chrome/browser/downloads/downloads.properties
new file mode 100644
index 0000000000..c253e7345f
--- /dev/null
+++ b/l10n-cy/browser/chrome/browser/downloads/downloads.properties
@@ -0,0 +1,83 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this file,
+# You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# LOCALIZATION NOTE (stateStarting):
+# Indicates that the download is starting.
+stateStarting=Cychwyn…
+# LOCALIZATION NOTE (stateFailed):
+# Indicates that the download failed because of an error.
+stateFailed=Methiant
+# LOCALIZATION NOTE (statePaused):
+# Indicates that the download was paused by the user.
+statePaused=Oedi
+# LOCALIZATION NOTE (stateCanceled):
+# Indicates that the download was canceled by the user.
+stateCanceled=Diddymwyd
+# LOCALIZATION NOTE (stateCompleted):
+# Indicates that the download was completed.
+stateCompleted=Cwblhawyd
+# LOCALIZATION NOTE (stateBlockedParentalControls):
+# Indicates that the download was blocked by the Parental Controls feature of
+# Windows.  "Parental Controls" should be consistently named and capitalized
+# with the display of this feature in Windows.  The following article can
+# provide a reference for the translation of "Parental Controls" in various
+# languages:
+# http://windows.microsoft.com/en-US/windows-vista/Set-up-Parental-Controls
+stateBlockedParentalControls=Rhwystrwyd gan Rheolaeth Rhiant
+# LOCALIZATION NOTE (blockedMalware, blockedPotentiallyUnwanted,
+#                    blockedUncommon2):
+# These strings are shown in the panel for some types of blocked downloads. You
+# may need to adjust "downloads.width" in "downloads.dtd" if this turns out to
+# be longer than the other existing status strings.
+blockedMalware=Mae'r ffeil ynn cynnwys firws neu ddrwgwar.
+blockedPotentiallyUnwanted=Gall y ffeil hon niweidio eich cyfrifiadur.
+blockedPotentiallyInsecure=Ffeil heb ei llwytho i lawr: Perygl diogelwch posib.
+blockedUncommon2=Nid yw'r ffeil hon yn cael ei llwytho i lawr yn aml.
+
+# LOCALIZATION NOTE (fileMovedOrMissing):
+# Displayed when a complete download which is not at the original folder.
+fileMovedOrMissing=Ffeil wedi ei symud neu ar goll
+
+# LOCALIZATION NOTE (fileDeleted):
+# Displayed when a downloaded file has been deleted by Firefox, e.g. by the
+# "Delete File" context menu item.
+fileDeleted=Ffeil wedi'i dileu
+
+# LOCALIZATION NOTE (unblockHeaderUnblock, unblockHeaderOpen,
+#                    unblockTypeMalware, unblockTypePotentiallyUnwanted2,
+#                    unblockTypeUncommon2, unblockTip2, unblockButtonOpen,
+#                    unblockButtonUnblock, unblockButtonConfirmBlock, unblockInsecure2):
+# These strings are displayed in the dialog shown when the user asks a blocked
+# download to be unblocked.  The severity of the threat is expressed in
+# descending order by the unblockType strings, it is higher for files detected
+# as malware and lower for uncommon downloads.
+unblockHeaderUnblock=Ydych chi'n siŵr eich bod eisiau caniatáu'r llwytho i lawr?
+unblockHeaderOpen=Ydych chi'n siŵr eich bod eisiau agor y ffeil hon?
+unblockTypeMalware=Mae'r ffeil yn cynnwys firws neu ddrwgwar arall fydd yn gwneud drwg i'ch cyfrifiadur.
+unblockTypePotentiallyUnwanted2=Gall y ffeil hon, sydd wedi ei ffugio i edrych fel rhaglen cynorthwyol, wneud newidiadau annisgwyl i'ch rhaglenni a'ch gosodiadau.
+unblockTypeUncommon2=Nid yw'r ffeil hon yn cael ei llwytho i lawr yn aml ac nad yw'n ddiogel ei hagor. Gall fod yn cynnwys firws neu wneud newidiadau annisgwyl i' ch rhaglenni a'ch gosodiadau.
+unblockInsecure=Mae'r ffeil yn defnyddio cysylltiad anniogel. Efallai y bydd yn llwgr neu wedi cael ymyrraeth yn ystod y broses llwytho i lawr.
+unblockInsecure2=Cafodd y llwyth ei gynnig dros HTTP er bod y ddogfen gyfredol wedi'i chyflwyno dros gysylltiad HTTPS diogel. Os ewch ymlaen, efallai y bydd y llwyth yn cael ei lygru neu ymyrryd ag ef yn ystod y broses llwytho i lawr.
+unblockTip2=Gallwch chwilio am ffynhonnell llwytho i lawr arall neu geisio llwytho'r ffeil i lawr rhywbryd eto.
+unblockButtonOpen=Agor
+unblockButtonUnblock=Caniatáu'r llwytho i lawr
+unblockButtonConfirmBlock=Tynnu ffeil
+
+# LOCALIZATION NOTE (sizeWithUnits):
+# %1$S is replaced with the size number, and %2$S with the measurement unit.
+sizeWithUnits=%1$S %2$S
+sizeUnknown=Maint anhysbys
+
+# LOCALIZATION NOTE (statusSeparator, statusSeparatorBeforeNumber):
+# These strings define templates for the separation of different elements in the
+# status line of a download item.  As a separator, by default we use the Unicode
+# character U+2014 'EM DASH' (long dash).  Examples of status lines include
+# "Canceled - 222.net", "1.1 MB - website2.com", or "Paused -  1.1 MB".  Note
+# that we use a wider space after the separator when it is followed by a number,
+# just to avoid visually confusing it with with a minus sign with some fonts.
+# If you use a different separator, this might not be necessary.  However, there
+# is usually no need to change the separator or the order of the substitutions,
+# even for right-to-left languages, unless the defaults are not suitable.
+statusSeparator=%1$S %2$S
+statusSeparatorBeforeNumber=%1$S —  %2$S
diff --git a/l10n-cy/browser/chrome/browser/feeds/subscribe.properties b/l10n-cy/browser/chrome/browser/feeds/subscribe.properties
new file mode 100644
index 0000000000..dc9b3fc4dd
--- /dev/null
+++ b/l10n-cy/browser/chrome/browser/feeds/subscribe.properties
@@ -0,0 +1,10 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# LOCALIZATION NOTE (addProtocolHandlerMessage):
+# Message displayed when adding a protocol handler:
+# %1$S is the application's domain, %2$S is the type of protocol
+addProtocolHandlerMessage=Ychwanegu “%1$S” fel rhaglen ar gyfer dolenni %2$S?
+addProtocolHandlerAddButton=Ychwanegu Rhaglen
+addProtocolHandlerAddButtonAccesskey=Y
diff --git a/l10n-cy/browser/chrome/browser/places/bookmarkProperties.properties b/l10n-cy/browser/chrome/browser/places/bookmarkProperties.properties
new file mode 100644
index 0000000000..2de178e991
--- /dev/null
+++ b/l10n-cy/browser/chrome/browser/places/bookmarkProperties.properties
@@ -0,0 +1,24 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+dialogAcceptLabelAddItem=Ychwanegu
+dialogAcceptLabelSaveItem=Cadw
+dialogAcceptLabelAddMulti=Ychwanegu Nodau Tudalen
+dialogAcceptLabelEdit=Cadw
+dialogTitleAddBookmark=Nod Tudalen Newydd
+dialogTitleAddFolder=Ffolder Newydd
+dialogTitleAddMulti=Nodau Tudalen Newydd
+dialogTitleEdit=Priodweddau "%S"
+
+dialogTitleAddNewBookmark2=Ychwanegu nod tudalen
+dialogTitleEditBookmark=Golygu “%S”
+dialogTitleEditBookmark2=Golygu nod tudalen
+dialogTitleAddBookmarksFolder=Ychwanegu ffolder nodau tudalen
+dialogTitleAddBookmarkFolder=Ychwanegu ffolder nodau tudalen
+dialogTitleEditBookmarksFolder=Golygu ffolder nodau tudalen
+dialogTitleEditBookmarkFolder=Golygu ffolder nodau tudalen
+
+bookmarkAllTabsDefault=[Enw Ffolder]
+newFolderDefault=Ffolder Newydd
+newBookmarkDefault=Nod Tudalen Newydd
diff --git a/l10n-cy/browser/chrome/browser/places/places.properties b/l10n-cy/browser/chrome/browser/places/places.properties
new file mode 100644
index 0000000000..78baa1d449
--- /dev/null
+++ b/l10n-cy/browser/chrome/browser/places/places.properties
@@ -0,0 +1,79 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+load-js-data-url-error=Am resymau diogelwch, ni fydd modd gosod javascript na urlau data o'r ffenestr hanes na bar ochr.
+noTitle=(dim teitl)
+
+bookmarksMenuEmptyFolder=(Gwag)
+
+bookmarksBackupTitle=Enw ffeil nodau tudalen wrth gefn
+
+bookmarksRestoreAlertTitle=Adfer i'r Nodau Tudalen
+bookmarksRestoreAlert=Bydd hwn yn newid eich holl nodau tudalen presennol drwy'r copïo wrth gefn. Iawn?
+bookmarksRestoreTitle=Dewis nodau tudalen wrth gefn
+bookmarksRestoreFilterName=JSON
+
+bookmarksRestoreFormatError=Math ffeil nad yw'n cael ei chynnal.
+bookmarksRestoreParseError=Methu prosesu'r ffeil wrth gefn.
+
+# LOCALIZATION NOTE (view.sortBy.1.name.label): sortBy properties are versioned.
+# When any of these changes, all of the properties must be bumped, and the
+# change must be annotated here.  Both label and accesskey must be updated.
+# - version 1: changed view.sortBy.1.date.
+view.sortBy.1.name.label=Trefnu yn ôl Enw
+view.sortBy.1.name.accesskey=E
+view.sortBy.1.url.label=Trefnu yn ôl Lleoliad
+view.sortBy.1.url.accesskey=L
+view.sortBy.1.date.label=Trefnu yn ôl yr Ymweliad Diweddaraf
+view.sortBy.1.date.accesskey=Y
+view.sortBy.1.visitCount.label=Trefnu yn ôl Cyfrif Ymweliadau
+view.sortBy.1.visitCount.accesskey=C
+view.sortBy.1.dateAdded.label=Trefnu yn ôl Ychwanegwyd
+view.sortBy.1.dateAdded.accesskey=Y
+view.sortBy.1.lastModified.label=Trefnu yn ôl Newid Diwethaf
+view.sortBy.1.lastModified.accesskey=N
+view.sortBy.1.tags.label=Trefnu yn ôl Tagiau
+view.sortBy.1.tags.accesskey=T
+
+searchBookmarks=Chwilio'r Nodau Tudalen
+searchHistory=Hanes Chwilio
+searchDownloads=Chwilio'r Llwytho i Lawr
+
+SelectImport=Mewnforio Ffeil Nodau Tudalen
+EnterExport=Allforio Ffeil Nodau Tudalen
+
+detailsPane.noItems=Dim eitemau
+# LOCALIZATION NOTE (detailsPane.itemsCountLabel): Semicolon-separated list of plural forms.
+# See: http://developer.mozilla.org/en/docs/Localization_and_Plurals
+# #1 number of items
+# example: 111 items
+detailsPane.itemsCountLabel=Dim eitemau;#1eitem;#1eitem;#1eitem;#1eitem;#1eitem
+
+# LOCALIZATION NOTE (lockPrompt.text)
+# %S will be replaced with the application name.
+lockPrompt.text=Ni fydd y system nodau tudalen a hanes yn weithredol gan fod un o ffeiliau %S yn cael ei defnyddio gan raglen arall. Mae rhai meddalwedd diogelwch yn gallu achosi'r broblem yma.
+
+# LOCALIZATION NOTE (cmd.deleteSinglePage.accesskey,
+# cmd.deleteMultiplePages.accesskey): these accesskeys can use the same
+# character, since they're never displayed at the same time
+cmd.deleteSinglePage.label=Dileu Tudalen
+cmd.deleteSinglePage.accesskey=D
+cmd.deleteMultiplePages.label=Dileu Tudalennau
+cmd.deleteMultiplePages.accesskey=D
+
+# LOCALIZATION NOTE (cmd.bookmarkSinglePage.accesskey,
+# cmd.bookmarkMultiplePages.accesskey): these accesskeys can use the same
+# character, since they're never displayed at the same time
+cmd.bookmarkSinglePage.label=Gosod Nod i Dudalen
+cmd.bookmarkSinglePage.accesskey=G
+cmd.bookmarkMultiplePages.label=Gosod Nodau i Dudalennau
+cmd.bookmarkMultiplePages.accesskey=N
+
+# LOCALIZATION NOTE (cmd.bookmarkSinglePage.accesskey,
+# cmd.bookmarkMultiplePages.accesskey): these accesskeys can use the same
+# character, since they're never displayed at the same time
+cmd.bookmarkSinglePage2.label=Gosod Nod i Dudalen…
+cmd.bookmarkSinglePage2.accesskey=N
+cmd.bookmarkMultiplePages2.label=Gosod Nod i Dudalennau…
+cmd.bookmarkMultiplePages2.accesskey=N
diff --git a/l10n-cy/browser/chrome/browser/safebrowsing/safebrowsing.properties b/l10n-cy/browser/chrome/browser/safebrowsing/safebrowsing.properties
new file mode 100644
index 0000000000..da985334dd
--- /dev/null
+++ b/l10n-cy/browser/chrome/browser/safebrowsing/safebrowsing.properties
@@ -0,0 +1,6 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+errorReportFalseDeceptiveTitle=Nid yw hon yn wefan twyllodrus
+errorReportFalseDeceptiveMessage=Nid yw'n bosib adrodd ar y gwall hwn ar hyn o bryd.
diff --git a/l10n-cy/browser/chrome/browser/search.properties b/l10n-cy/browser/chrome/browser/search.properties
new file mode 100644
index 0000000000..f597449fb7
--- /dev/null
+++ b/l10n-cy/browser/chrome/browser/search.properties
@@ -0,0 +1,33 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+searchtip=Chwilio gan ddefnyddio %S
+
+# LOCALIZATION NOTE (searchHeader): this is displayed at the top of the panel
+# showing search suggestions.
+# %S is replaced with the name of the current default search engine.
+searchHeader=Chwilio gyda %S
+
+# LOCALIZATION NOTE (cmd_pasteAndSearch): "Search" is a verb, this is the
+# search bar equivalent to the url bar's "Paste & Go"
+cmd_pasteAndSearch=Gludo a Chwilio
+
+cmd_clearHistory=Clirio Hanes Chwilio
+cmd_clearHistory_accesskey=H
+
+# LOCALIZATION NOTE (searchForSomethingWith2):
+# This string is used to build the header above the list of one-click
+# search providers:  "Search for <user-typed string> with:"
+searchForSomethingWith2=Chwilio am %S gyda:
+
+# LOCALIZATION NOTE (searchWithHeader):
+# The wording of this string should be as close as possible to
+# searchForSomethingWith2. This string will be used when the user
+# has not typed anything.
+searchWithHeader=Chwilio gyda:
+
+# LOCALIZATION NOTE (searchSettings):
+# This is the label for the button that opens Search preferences.
+searchSettings=Gosodiadau Chwilio
+
diff --git a/l10n-cy/browser/chrome/browser/shellservice.properties b/l10n-cy/browser/chrome/browser/shellservice.properties
new file mode 100644
index 0000000000..259a20aeae
--- /dev/null
+++ b/l10n-cy/browser/chrome/browser/shellservice.properties
@@ -0,0 +1,16 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# LOCALIZATION NOTE (setDefaultBrowserTitle, setDefaultBrowserMessage, setDefaultBrowserDontAsk, setDefaultBrowserAlertConfirm.label, setDefaultBrowserAlertNotNow.label):
+# These strings are used as an alternative to the ones above, in a modal dialog.
+# %S will be replaced by brandShortName
+setDefaultBrowserTitle=Porwr Rhagosodedig
+setDefaultBrowserMessage=Nid %S yw eich porwr rhagosodedig. Hoffech chi ei osod fel eich porwr arferol?
+setDefaultBrowserDontAsk=Gwiriwch bob tro wrth gychwyn %S.
+setDefaultBrowserAlertConfirm.label=Defnyddio %S fel fy mhorwr rhagosodedig
+setDefaultBrowserAlertNotNow.label=Nid nawr
+
+desktopBackgroundLeafNameWin=Desktop Background.bmp
+DesktopBackgroundDownloading=Cadw Darlun…
+DesktopBackgroundSet=Gosod Cefndir Bwrdd Gwaith
diff --git a/l10n-cy/browser/chrome/browser/siteData.properties b/l10n-cy/browser/chrome/browser/siteData.properties
new file mode 100644
index 0000000000..c1fb96ebad
--- /dev/null
+++ b/l10n-cy/browser/chrome/browser/siteData.properties
@@ -0,0 +1,8 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+clearSiteDataPromptTitle=Clirio'r holl gwcis a data gwefan
+# LOCALIZATION NOTE (clearSiteDataPromptText): %S = brandShortName
+clearSiteDataPromptText=Bydd dewis ‘Clirio Nawr’ yn clirio'r holl gwcis a data gwefan wedi ei storio gan %S. Gall hyn eich allgofnodi o wefannau a thynnu cynnwys all-lein.
+clearSiteDataNow=Clirio Nawr
diff --git a/l10n-cy/browser/chrome/browser/sitePermissions.properties b/l10n-cy/browser/chrome/browser/sitePermissions.properties
new file mode 100644
index 0000000000..0d28d3db42
--- /dev/null
+++ b/l10n-cy/browser/chrome/browser/sitePermissions.properties
@@ -0,0 +1,55 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# LOCALIZATION NOTE (state.current.allowed,
+#                    state.current.allowedForSession,
+#                    state.current.allowedTemporarily,
+#                    state.current.blockedTemporarily,
+#                    state.current.blocked,
+#                    state.current.hide):
+# This label is used to display active permission states in the site
+# identity popup (which does not have a lot of screen space).
+state.current.allowed = Caniatáu
+state.current.allowedForSession = Caniatáu ar gyfer y Sesiwn
+state.current.allowedTemporarily = Caniatáu Dros Dro
+state.current.blockedTemporarily = Rhwystro Dros Dro
+state.current.blocked = Wedi ei Rwystro
+state.current.prompt = Gofyn Bob Tro
+
+# LOCALIZATION NOTE (state.multichoice.alwaysAsk,
+#                    state.multichoice.allow,
+#                    state.multichoice.allowForSession,
+#                    state.multichoice.block):
+# Used to label permission state checkboxes in the page info dialog.
+state.multichoice.alwaysAsk = Gofyn Bob Tro
+state.multichoice.allow = Caniatáu
+state.multichoice.allowForSession = Caniatáu ar gyfer y Sesiwn
+state.multichoice.block = Rhwystro
+
+state.multichoice.autoplayblock = Rhwystro Sain
+state.multichoice.autoplayblockall = Rhwystro Sain a Fideo
+state.multichoice.autoplayallow = Caniatáu Sain a Fideo
+
+permission.autoplay.label = Awtochwarae
+permission.cookie.label = Gosod Cwcis
+permission.desktop-notification3.label = Anfon Hysbysiadau
+permission.camera.label = Defnyddio'r Camera
+permission.microphone.label = Defnyddio'r Meicroffon
+permission.screen.label = Rhannu'r Sgrin
+# LOCALIZATION NOTE (permission.speaker.label):
+# Short form for (permission to) "Choose and change audio output devices".
+permission.speaker.label = Dewiswch seinyddion
+permission.install.label = Gosod Ychwanegion
+permission.popup.label = Agor Llamlenni
+permission.geo.label = Mynediad i'ch Lleoliad
+permission.xr.label = Cael Mynediad at Ddyfeisiau Rhithrealaeth
+permission.shortcuts.label = Gwrthwneud Llwybrau Byr Bysellfwrdd
+permission.focus-tab-by-prompt.label = Newid i'r Tab hwn
+permission.persistent-storage.label = Cadw Data mewn Storfa Barhaus
+permission.canvas.label = Tynnu Data Canvas
+permission.midi.label = Mynediad at ddyfeisiau MIDI
+permission.midi-sysex.label = Mynediad at ddyfeisiau MIDI sydd â Chefnogaeth SysEx
+# LOCALIZATION NOTE (permission.open-protocol-handler.label):
+# Open as a verb. "This site may open applications".
+permission.open-protocol-handler.label = Agor rhaglenni
diff --git a/l10n-cy/browser/chrome/browser/syncSetup.properties b/l10n-cy/browser/chrome/browser/syncSetup.properties
new file mode 100644
index 0000000000..9674785b75
--- /dev/null
+++ b/l10n-cy/browser/chrome/browser/syncSetup.properties
@@ -0,0 +1,14 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# Several other strings are used (via Weave.Status.login), but they come from
+#  /services/sync
+
+# Firefox Accounts based setup.
+continue.label = Ymlaen
+
+relinkVerify.title = Rhybudd Cyfuno
+relinkVerify.heading = Ydych chi'n siŵr eich bod am fewngofnodi i Sync?
+# LOCALIZATION NOTE (relinkVerify.description): Email address of a user previously signed into sync.
+relinkVerify.description = Roedd defnyddiwr gwahanol ar y cyfrifiadur yma wedi ei fewngofnodi i Sync. Bydd mewngofnodi yn uno nodau tudalen, cyfrineiriau a gosodiadau eraill gyda %S
diff --git a/l10n-cy/browser/chrome/browser/tabbrowser.properties b/l10n-cy/browser/chrome/browser/tabbrowser.properties
new file mode 100644
index 0000000000..bf4af10f41
--- /dev/null
+++ b/l10n-cy/browser/chrome/browser/tabbrowser.properties
@@ -0,0 +1,106 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+tabs.emptyTabTitle=Tab Newydd
+tabs.emptyPrivateTabTitle=Pori Preifat
+tabs.emptyPrivateTabTitle2=Tab Preifat Newydd
+tabs.closeTab=Cau Tab
+tabs.close=Cau
+
+# This section applies when closing a window with more than one tab open,
+# or when quitting when only one window is open.
+# LOCALIZATION NOTE (tabs.closeTabsTitle):
+# Semicolon-separated list of plural forms. See:
+# http://developer.mozilla.org/en/docs/Localization_and_Plurals
+# The singular form is not considered since this string is used only for
+# multiple tabs.
+tabs.closeTabsTitle=Cau #1 tabiau?;Cau #1 tab?;Cau #1 tab?;Cau #1 tab?;Cau #1 tab?;Cau #1 tab?
+tabs.closeTabsConfirmCheckbox=Cadarnhau cyn cau tabiau lluosog
+tabs.closeButtonMultiple=Cau tabiau
+
+# This section applies when quitting using the menu and multiple windows are open.
+# LOCALIZATION NOTE (tabs.closeTitleTabs):
+# Semicolon-separated list of plural forms. See:
+# http://developer.mozilla.org/en/docs/Localization_and_Plurals
+# The forms for 0 or 1 items are not considered since this string is used only for
+# multiple windows. The %S replacement form will be replaced with the contents
+tabs.closeWindowsTitle=Cau #1 ffenestri?;Cau #1 ffenestr?;Cau #1 ffenestr?;Cau #1 ffenestr?;Cau #1 ffenestr?;Cau #1 ffenestr?
+tabs.closeWindowsButton=Cau a gadael
+# Same as tabs.closeWindowsButton, but on Windows
+tabs.closeWindowsButtonWin=Cau a gadael
+
+# LOCALIZATION NOTE (tabs.closeTabsWithKeyTitle and closeTabsWithKeyButton):
+# This section applies when quitting using the keyboard shortcut (Ctrl/Cmd+Q)
+# Windows does not show a prompt on quit when using the keyboard shortcut by
+# default.
+# %S is replaced with brandShorterName
+tabs.closeTabsWithKeyTitle=Cau ffenestr a gadael %S?
+# %S is replaced with brandShorterName
+tabs.closeTabsWithKeyButton=Gadael %S
+
+# LOCALIZATION NOTE (tabs.closeTabsWithKeyConfirmCheckbox):
+# %S is replaced with the text of the keyboard shortcut for quitting.
+tabs.closeTabsWithKeyConfirmCheckbox=Cadarnhau cyn gadael gyda %S
+
+# LOCALIZATION NOTE (tabs.closeTabs.tooltip):
+# Semicolon-separated list of plural forms. See:
+# http://developer.mozilla.org/en/docs/Localization_and_Plurals
+# #1 is the number of tabs that will be closed. This is ignored for the
+# single tab case in English, but can be used by other locales as necessary.
+tabs.closeTabs.tooltip=Cau tab;Cau #1 tab;Cau #1 dab;Cau #1 tab;Cau #1 tab;Cau #1 tab
+
+# LOCALIZATION NOTE (tabs.muteAudio2.tooltip):
+# Semicolon-separated list of plural forms. See:
+# http://developer.mozilla.org/en/docs/Localization_and_Plurals
+# %S is the keyboard shortcut for "Mute tab".
+# #1 is the number of tabs that will be muted. This is ignored for the
+# single tab case in English, but can be used by other locales as necessary.
+tabs.muteAudio2.tooltip=Tewi tab (%S);Tewi #1 tab (%S);Tewi #1 tab (%S);Tewi #1 tab (%S);Tewi #1 tab (%S);Tewi #1 tab (%S)
+
+# LOCALIZATION NOTE (tabs.unmuteAudio2.tooltip):
+# Semicolon-separated list of plural forms. See:
+# http://developer.mozilla.org/en/docs/Localization_and_Plurals
+# %S is the keyboard shortcut for "Unmute tab".
+# #1 is the number of tabs that will be unmuted. This is ignored for the
+# single tab case in English, but can be used by other locales as necessary.
+tabs.unmuteAudio2.tooltip=Dad-dewi tab (%S);Dad-dewi #1 tab (%S);Dad-dewi #1 tab (%S);Dad-dewi #1 tab (%S);Dad-dewi #1 tab (%S);Dad-dewi #1 tab (%S)
+
+# LOCALIZATION NOTE (tabs.muteAudio2.background.tooltip):
+# Semicolon-separated list of plural forms. See:
+# http://developer.mozilla.org/en/docs/Localization_and_Plurals
+# #1 is the number of tabs that will be muted. This is ignored for the
+# single tab case in English, but can be used by other locales as necessary.
+tabs.muteAudio2.background.tooltip=Tewi tab;Tewi #1 tab;Tewi #1 tab;Tewi #1 tab;Tewi #1 tab;Tewi #1 tab
+
+# LOCALIZATION NOTE (tabs.unmuteAudio2.background.tooltip):
+# Semicolon-separated list of plural forms. See:
+# http://developer.mozilla.org/en/docs/Localization_and_Plurals
+# #1 is the number of tabs that will be unmuted. This is ignored for the
+# single tab case in English, but can be used by other locales as necessary.
+tabs.unmuteAudio2.background.tooltip=Dad-dewi tab;Dad-dewi #1 tab;Dad-dewi #1 tab;Dad-dewi #1 tab;Dad-dewi #1 tab;Dad-dewi #1 tab
+
+# LOCALIZATION NOTE (tabs.unblockAudio2.tooltip):
+# Semicolon-separated list of plural forms. See:
+# http://developer.mozilla.org/en/docs/Localization_and_Plurals
+# #1 is the number of tabs that will have their audio unblocked. This is ignored for the
+# single tab case in English, but can be used by other locales as necessary.
+tabs.unblockAudio2.tooltip=Chwarae tab;Chwarae #1 tab;Chwarae #1 tab;Chwarae #1 tab;Chwarae #1 tab;Chwarae #1 tab
+
+# LOCALIZATION NOTE (tabs.containers.tooltip):
+# Displayed as a tooltip on container tabs
+# %1$S is the title of the current tab
+# %2$S is the name of the current container
+tabs.containers.tooltip=%1$S - %2$S
+
+# LOCALIZATION NOTE (tabs.openWarningTitle, tabs.openWarningMultipleBranded, tabs.openButtonMultiple, tabs.openWarningPromptMeBranded):
+# These items are moved from chrome/browser/places/places.properties
+# Now they are not specific to bookmark.
+tabs.openWarningTitle=Cadarnhau ar agor
+tabs.openWarningMultipleBranded=Rydych ar fin agor %S tab.  Gall hyn arafu %S tra fo'r tudalennau'n llwytho.  Ydych chi'n siŵr eich bod am barhau?
+tabs.openButtonMultiple=Agor tabiau
+tabs.openWarningPromptMeBranded=Rhybuddio y gall agor tabiau niferus arafu %S
+
+browsewithcaret.checkMsg=Peidio dangos y blwch deialog yma eto.
+browsewithcaret.checkWindowTitle=Pori Caret
+browsewithcaret.checkLabel=Mae pwyso F7 yn cychwyn a diffodd Pori Caret. Mae'r nodwedd hon yn gosod cyrchwr symudol ar dudalennau gwe, gan ganiatáu i chi ddewis testun gyda'r bysellfwrdd. Hoffech chi gychwyn Pori Caret?
diff --git a/l10n-cy/browser/chrome/browser/taskbar.properties b/l10n-cy/browser/chrome/browser/taskbar.properties
new file mode 100644
index 0000000000..6070acce07
--- /dev/null
+++ b/l10n-cy/browser/chrome/browser/taskbar.properties
@@ -0,0 +1,12 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+taskbar.tasks.newTab.label=Agor tab newydd
+taskbar.tasks.newTab.description=Agor tab porwr newydd.
+taskbar.tasks.newWindow.label=Agor ffenestr newydd
+taskbar.tasks.newWindow.description=Agor ffenestr porwr newydd.
+taskbar.tasks.newPrivateWindow.label=Ffenestr breifat newydd
+taskbar.tasks.newPrivateWindow.description=Agor ffenestr newydd yn y modd preifat.
+taskbar.frequent.label=Aml
+taskbar.recent.label=Diweddar
diff --git a/l10n-cy/browser/chrome/browser/translation.dtd b/l10n-cy/browser/chrome/browser/translation.dtd
new file mode 100644
index 0000000000..df5e12f2dc
--- /dev/null
+++ b/l10n-cy/browser/chrome/browser/translation.dtd
@@ -0,0 +1,76 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<!-- LOCALIZATION NOTE (translation.thisPageIsIn.label,
+  -                     translation.translateThisPage.label):
+  -  These 2 strings are used to construct a sentence that contains a dropdown
+  -  showing the detected language of the current web page.
+  -  In en-US it looks like this:
+  -    This page is in [detected language] Translate this page?
+  -  "detected language" here is a language name coming from the
+  -  global/languageNames.properties file; for some locales it may not be in
+  -  the correct grammar case to keep the same structure of the original
+  -  sentence. -->
+
+<!-- This file is only used by the Firefox Translations extension,
+   - and should be removed once possible.
+   - See: https://bugzilla.mozilla.org/show_bug.cgi?id=1788595 -->
+
+<!ENTITY translation.thisPageIsIn.label         "Mae'r dudalen yn">
+<!ENTITY translation.translateThisPage.label    "Cyfieithu'r dudalen?">
+<!ENTITY translation.translate.button           "Cyfieithu">
+<!ENTITY translation.notNow.button              "Nid Nawr">
+
+<!ENTITY translation.translatingContent.label   "Cyfieithu cynnwys y dudalen…">
+<!-- LOCALIZATION NOTE (translation.translatedFrom.label,
+  -                     translation.translatedTo.label,
+  -                     translation.translatedToSuffix.label):
+  -  These 3 strings are used to construct a sentence that contains 2 dropdowns
+  -  showing the source and target language of a translated web page.
+  -  In en-US it looks like this:
+  -    This page has been translated from [from language] to [to language]
+  -  "from language" and "to language" here are language names coming from the
+  -  global/languageNames.properties file; for some locales they may not be in
+  -  the correct grammar case to keep the same structure of the original
+  -  sentence.
+  -
+  -  translation.translatedToSuffix.label (empty in en-US) is for locales that
+  -  need to display some text after the second drop down for the sentence to
+  -  be grammatically correct. -->
+
+<!ENTITY translation.translatedFrom.label       "Mae'r dudalen wedi ei chyfieithu o'r">
+<!ENTITY translation.translatedTo.label         "at">
+<!ENTITY translation.translatedToSuffix.label   "">
+
+<!ENTITY translation.showOriginal.button        "Dangos y Gwreiddiol">
+<!ENTITY translation.showTranslation.button     "Dangos y Cyfieithiad">
+
+<!ENTITY translation.errorTranslating.label     "Bu gwall wrth gyfieithu'r dudalen hon.">
+<!ENTITY translation.tryAgain.button            "Ceisio Eto">
+
+<!ENTITY translation.serviceUnavailable.label   "Nid yw cyfieithu ar gael ar hyn o bryd. Ceisiwch eto.">
+
+<!ENTITY translation.options.menu               "Dewisiadau">
+<!-- LOCALIZATION NOTE (translation.options.neverForSite.accesskey,
+  -                     translation.options.preferences.accesskey):
+  -  The accesskey values used here should not clash with the value used for
+  -  translation.options.neverForLanguage.accesskey in translation.properties
+  -->
+<!ENTITY translation.options.neverForSite.label "Peidio byth cyfieithu'r wefan hon">
+<!ENTITY translation.options.neverForSite.accesskey "b">
+<!ENTITY translation.options.preferences.label  "Dewisiadau cyfieithu">
+<!ENTITY translation.options.preferences.accesskey "D">
+<!-- LOCALIZATION NOTE (translation.options.attribution.beforeLogo,
+  -                     translation.options.attribution.afterLogo):
+  -  These 2 strings are displayed before and after a 'Microsoft Translator'
+  -  logo.
+  -->
+
+<!-- LOCALIZATION NOTE (translation.options.attribution.poweredByYandex,
+                        translation.options.attribution.beforeLogo,
+  -                     translation.options.attribution.afterLogo):
+  -  translation.options.attribution.poweredByYandex is displayed instead of
+  -  the other two strings when yandex translation engine is preferred by the
+  -  user.
+  -->
+
diff --git a/l10n-cy/browser/chrome/browser/translation.properties b/l10n-cy/browser/chrome/browser/translation.properties
new file mode 100644
index 0000000000..928a0994dc
--- /dev/null
+++ b/l10n-cy/browser/chrome/browser/translation.properties
@@ -0,0 +1,12 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# LOCALIZATION NOTE (translation.options.neverForLanguage.label):
+#  %S is a language name coming from the global/languageNames.properties file.
+translation.options.neverForLanguage.label=Peidio cyfieithu %S
+
+# LOCALIZATION NOTE (translation.options.neverForLanguage.accesskey):
+# The accesskey value used here should not clash with the values used for
+# translation.options.*.accesskey in translation.dtd
+translation.options.neverForLanguage.accesskey=P
diff --git a/l10n-cy/browser/chrome/browser/uiDensity.properties b/l10n-cy/browser/chrome/browser/uiDensity.properties
new file mode 100644
index 0000000000..07330a3771
--- /dev/null
+++ b/l10n-cy/browser/chrome/browser/uiDensity.properties
@@ -0,0 +1,5 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+uiDensity.menuitem-touch.acceltext=Galluogwyd y Modd Tabled
diff --git a/l10n-cy/browser/chrome/browser/webrtcIndicator.properties b/l10n-cy/browser/chrome/browser/webrtcIndicator.properties
new file mode 100644
index 0000000000..269e6411ab
--- /dev/null
+++ b/l10n-cy/browser/chrome/browser/webrtcIndicator.properties
@@ -0,0 +1,61 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# LOCALIZATION NOTE : FILE This file contains the webrtc global indicator strings
+
+# LOCALIZATION NOTE (webrtcIndicator.windowtitle): %S is the brand name (e.g. Firefox).
+# This string is used so that the window has a title in tools that enumerate/look for window
+# titles. It is not normally visible anywhere.
+webrtcIndicator.windowtitle = %S - Dangosydd Rhannu
+
+webrtcIndicator.sharingCameraAndMicrophone.tooltip = Mae eich camera a'ch meicroffon yn cael eu rhannu. Cliciwch i reoli'r rhannu.
+webrtcIndicator.sharingCamera.tooltip              = Mae eich camera'n cael ei rannu. Cliciwch i reoli'r rhannu.
+webrtcIndicator.sharingMicrophone.tooltip          = Mae eich meicroffon yn cael ei rannu. Cliciwch i reoli'r rhannu.
+webrtcIndicator.sharingApplication.tooltip = Mae rhaglen yn ei rannu. Cliciwch i reoli'r rhannu.
+webrtcIndicator.sharingScreen.tooltip = Mae eich sgrin yn cael ei rannu. Cliciwch i reoli'r rhannu.
+webrtcIndicator.sharingWindow.tooltip = Mae ffenestr yn cael ei rannu. Cliciwch i reoli'r rhannu.
+webrtcIndicator.sharingBrowser.tooltip = Mae tab yn cael ei rannu. Cliciwch i reoli'r rhannu.
+
+
+# LOCALIZATION NOTE : The following strings are only used on Mac for
+# menus attached to icons near the clock on the mac menubar.
+
+# LOCALIZATION NOTE (webrtcIndicator.sharing*With.menuitem):
+# %S is the title of the tab using the share.
+webrtcIndicator.sharingCameraWith.menuitem = Rhannu camera gyda "%S"
+webrtcIndicator.sharingMicrophoneWith.menuitem = Rhannu Meicroffon gyda "%S"
+webrtcIndicator.sharingApplicationWith.menuitem = Rhannu Rhaglen gyda "%S"
+webrtcIndicator.sharingScreenWith.menuitem = Rhannu Sgrin gyda "%S"
+webrtcIndicator.sharingWindowWith.menuitem = Rhannu Ffenestr gyda "%S"
+webrtcIndicator.sharingBrowserWith.menuitem = Rhannu Tab gyda "%S"
+webrtcIndicator.controlSharing.menuitem = Rhannu Rheoli
+# LOCALIZATION NOTE (webrtcIndicator.sharingCameraWithNTabs.menuitem):
+# Semicolon-separated list of plural forms. See:
+# http://developer.mozilla.org/en/docs/Localization_and_Plurals
+webrtcIndicator.sharingCameraWithNTabs.menuitem = Peidio rhannu Camera gyda thabiau;Rhannu Camera gyda #1 tab;Rhannu Camera gyda #1 dab;Rhannu Camera gyda #1 thab;Rhannu Camera gyda #1 thab;Rhannu Camera gyda #1 tab
+# LOCALIZATION NOTE (webrtcIndicator.sharingMicrophoneWithNTabs.menuitem):
+# Semicolon-separated list of plural forms. See:
+# http://developer.mozilla.org/en/docs/Localization_and_Plurals
+webrtcIndicator.sharingMicrophoneWithNTabs.menuitem = Peidio rhannu Meicroffon gyda thabiau;Rhannu Meicroffon gydag #1 tab;Rhannu Meicroffon gyda #1 dab;Rhannu Meicroffon gyda #1 thab;Rhannu Meicroffon gyda #1 thab;Rhannu Meicroffon gyda #1 tab
+# LOCALIZATION NOTE (webrtcIndicator.sharingApplicationWithNTabs.menuitem):
+# Semicolon-separated list of plural forms. See:
+# http://developer.mozilla.org/en/docs/Localization_and_Plurals
+webrtcIndicator.sharingApplicationWithNTabs.menuitem = Peidio rhannu Rhaglen gyda thabiau;Rhannu Rhaglen gyda #1 tab;Rhannu Rhaglen gyda #1 dab;Rhannu Rhaglen gyda #1 thab;Rhannu Rhaglen gyda #1 thab;Rhannu Rhaglen gyda #1 tab
+# LOCALIZATION NOTE (webrtcIndicator.sharingScreenWithNTabs.menuitem):
+# Semicolon-separated list of plural forms. See:
+# http://developer.mozilla.org/en/docs/Localization_and_Plurals
+webrtcIndicator.sharingScreenWithNTabs.menuitem = Peidio rhannu'r Sgrin gyda thabiau;Rhannu'r Sgrin gyda #1 tab;Rhannu'r Sgrin gyda #1 dab;Rhannu'r Sgrin gyda #1 thab;Rhannu'r Sgrin gyda #1 thab;Rhannu'r Sgrin gyda #1 tab
+# LOCALIZATION NOTE (webrtcIndicator.sharingWindowWithNTabs.menuitem):
+# Semicolon-separated list of plural forms. See:
+# http://developer.mozilla.org/en/docs/Localization_and_Plurals
+webrtcIndicator.sharingWindowWithNTabs.menuitem = Peidio rhannu Ffenestr gyda thabiau;Rhannu Ffenestr gydag #1 tab;Rhannu Ffenestr gyda #1 dab;Rhannu Ffenestr gyda #1 thab;Rhannu Ffenestr gyda #1 thab;Rhannu Ffenestr gyda #1 tab
+# LOCALIZATION NOTE (webrtcIndicator.sharingBrowserWithNTabs.menuitem):
+# Semicolon-separated list of plural forms. See:
+# http://developer.mozilla.org/en/docs/Localization_and_Plurals
+# This message is shown when the contents of a tab is shared during a WebRTC
+# session, which currently is only possible with Loop/Hello.
+webrtcIndicator.sharingBrowserWithNTabs.menuitem = Peidio rhannu Tab gyda thabiau;Rhannu Tab gydag #1 tab;Rhannu Tab gyda #1 dab;Rhannu Tab gyda #1 thab;Rhannu Tab gyda #1 thab;Rhannu Tab gyda #1 tab
+# LOCALIZATION NOTE (webrtcIndicator.controlSharingOn.menuitem):
+# %S is the title of the tab using the share.
+webrtcIndicator.controlSharingOn.menuitem = Rheoli Rhannu gyda "%S"
diff --git a/l10n-cy/browser/chrome/overrides/appstrings.properties b/l10n-cy/browser/chrome/overrides/appstrings.properties
new file mode 100644
index 0000000000..fbb3615c0d
--- /dev/null
+++ b/l10n-cy/browser/chrome/overrides/appstrings.properties
@@ -0,0 +1,44 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+malformedURI2=Gwiriwch fod yr URL yn gywir a cheisiwch eto.
+fileNotFound=Nid yw Firefox yn gallu canfod y ffeil yn %S.
+fileAccessDenied=Nid yw ffeil %S yn ddarllenadwy.
+dnsNotFound2=Nid oedd modd cysylltu â'r gweinydd yn %S.
+unknownProtocolFound=Nid yw Firefox yn gwybod sut i agor y cyfeiriad hwn, gan fod un o'r protocolau canlynol (%S) heb eu cysylltu ag unrhyw raglen neu nid yw'n cael ei ganiatáu yn y cyd-destun hwn.
+connectionFailure=Nid yw Firefox yn gallu cysylltu â'r gweinydd yn %S.
+netInterrupt=Cafodd cysylltiad â %S ei darfu wrth i'r dudalen lwytho.
+netTimeout=Mae'r gweinydd yn %S yn cymryd gormod o amser i ymateb.
+redirectLoop=Mae Firefox wedi canfod fod gweinydd yn ailgyfeirio'r cais am y cyfeiriad yma mewn ffordd na fydd yn cael ei gwblhau.
+## LOCALIZATION NOTE (confirmRepostPrompt): In this item, don’t translate "%S"
+confirmRepostPrompt=I ddangos y dudalen hon, rhaid i %S anfon gwybodaeth fydd yn ailadrodd unrhyw weithred (megis chwilio neu gadarnhau gorchymyn) gafodd ei chyflawni ynghynt.
+resendButton.label=Ail anfon
+unknownSocketType=Nid yw Firefox yn gwybod sut i gyfathrebu gyda'r gweinydd.
+netReset=Cafodd y cysylltiad i'r gweinydd ei ailosod wrth i'r dudalen lwytho.
+notCached=Nid yw'r ddogfen ar gael bellach.
+netOffline=Mae Firefox yn y modd all-lein ar hyn o bryd ac yn methu pori.
+isprinting=Nid oes modd i'r ddogfen newid wrth Argraffu neu yn Rhagolwg Argraffu.
+deniedPortAccess=Mae'r cyfeiriad yn defnyddio porth rhwydwaith sy'n cael ei ddefnyddio fel arfer i ddibenion heblaw pori'r We. Mae Firefox wedi gwrthod y cais er eich lles.
+proxyResolveFailure=Mae Firefox wedi ei ffurfweddu i ddefnyddio gweinydd dirprwy nad oes modd ei ganfod.
+proxyConnectFailure=Mae Firefox wedi ei ffurfweddu i ddefnyddio gweinydd dirprwy sy'n gwrthod cysylltiadau.
+contentEncodingError=Nid oes modd dangos y dudalen rydych yn ceisio ei darllen am ei bod yn defnyddio math o gywasgiad nad yw'n cael ei gynnal.
+unsafeContentType=Nid oes modd dangos y dudalen rydych yn ceisio ei darllen am ei bod yn cynnwys math o ffeil gall fod nad yw'n ddiogel ei hagor. Cysylltwch â pherchennog y wefan i'w hysbysu o'r broblem.
+externalProtocolTitle=Cais Protocol Allanol
+externalProtocolPrompt=Rhaid cychwyn rhaglen allanol i drin dolenni %1$S: .\n\n\nCais dolen:\n\n%2$S\n\nRhaglen: %3$S\n\n\nOs nad oeddech yn disgwyl y cais hwn gall fod yn ymgais i gymryd mantais o wendid yn y rhaglen honno. Diddymwch y cais oni bai eich bod yn siŵr nad yw'n faleisus.\n
+#LOCALIZATION NOTE (externalProtocolUnknown): The following string is shown if the application name can't be determined
+externalProtocolUnknown=<Anhysbys>
+externalProtocolChkMsg=Cofio'r dewis ar gyfer y pob dolen o'r math yma.
+externalProtocolLaunchBtn=Cychwyn rhaglen
+malwareBlocked=Mae'r wefan %S wedi ei hysbysu fel gwefan ymosod ac wedi cael ei rwystro yn seiliedig ar y dewisiadau diogelwch.
+harmfulBlocked=Mae'r wefan yn %S yn hysbys fel gwefan niweidiol ac wedi cael ei rhwystro ar sail eich dewisiadau diogelwch.
+unwantedBlocked=Mae'r wefan %S wedi ei hysbysu fel gwefan ymosod ac wedi cael ei rwystro yn seiliedig ar y dewisiadau diogelwch.
+deceptiveBlocked=Mae'r wefan %S wedi ei hysbysu fel gwefan twyllodrus ac wedi cael ei rwystro yn seiliedig ar y dewisiadau diogelwch.
+cspBlocked=Mae gan y dudalen bolisi diogelwch cynnwys sy'n ei hatal rhag cael ei llwytho yn y ffordd yma.
+xfoBlocked=Mae gan y dudalen hon bolisi X-Frame-Options sy'n ei hatal rhag cael ei lwytho yn y cyd-destun hwn.
+corruptedContentErrorv2=Mae'r wefan %S wedi profi trosedd protocol rhwydwaith nad oes modd ei drwsio.
+## LOCALIZATION NOTE (sslv3Used) - Do not translate "%S".
+sslv3Used=Nid yw Firefox yn gallu gwarantu diogelwch eich data ar %S gan ei fod yn defnyddio SSLv3, protocol diogelwch sydd wedi torri.
+inadequateSecurityError=Mae'r wefan wedi ceisio negydu lefel annigonol o ddiogelwch.
+blockedByPolicy=Mae eich sefydliad wedi rhwystro mynediad i'r dudalen hon neu'r wefan.
+networkProtocolError=Mae'r wefan Firefox wedi profi trosedd protocol rhwydwaith nad oes modd ei drwsio.
diff --git a/l10n-cy/browser/chrome/overrides/netError.dtd b/l10n-cy/browser/chrome/overrides/netError.dtd
new file mode 100644
index 0000000000..323ec44f58
--- /dev/null
+++ b/l10n-cy/browser/chrome/overrides/netError.dtd
@@ -0,0 +1,129 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+
+<!ENTITY % brandDTD SYSTEM "chrome://branding/locale/brand.dtd">
+%brandDTD;
+
+<!ENTITY loadError.label "Anhawster llwytho tudalen">
+<!ENTITY retry.label "Ceisiwch eto">
+<!ENTITY returnToPreviousPage.label "Ewch Nôl">
+<!ENTITY returnToPreviousPage1.label "Ewch Nôl (Argymell)">
+<!ENTITY advanced2.label "Uwch…">
+<!ENTITY viewCertificate.label "Darllen Tystysgrif">
+
+<!-- Specific error messages -->
+
+<!ENTITY connectionFailure.longDesc "&sharedLongDesc;">
+
+<!ENTITY deniedPortAccess.longDesc "">
+
+<!ENTITY dnsNotFound.pageTitle "Heb Ganfod Gweinydd">
+<!ENTITY dnsNotFound.longDesc1 "
+<strong>Os yw'r cyfeiriad yna'n gywir, dyma dri pheth i chi roi cynnig arnyn nhw</strong>
+<ul>
+  <li>Ceisiwch eto'n hwyrach.</li>
+  <li>Gwiriwch eich cysylltiad rhwydwaith.</li>
+  <li>Os ydych wedi eich cysylltu ond y tu nôl i fur cadarn, gwiriwch fod gan &brandShortName; ganiatâd i gael mynediad i'r We.</li>
+</ul>
+">
+
+<!ENTITY fileNotFound.longDesc "<ul> <li>Gwiriwch yr enw ffeil am brif lythrennu neu wallau teipio eraill.</li> <li>Gwiriwch i weld os yw'r ffeil wedi symud, ailenwi neu ei dileu.</li> </ul>">
+
+<!ENTITY fileAccessDenied.longDesc "<ul> <li>Gall ei fod wedi ei dynnu, symud neu fod caniatâd ffeiliau yn rhwystro mynediad.</li> </ul>">
+
+<!ENTITY generic.longDesc "<p>Nid yw &brandShortName; yn gallu llwytho'r dudalen am ryw reswm.</p>">
+
+<!ENTITY captivePortal.title "Mewngofnodi i'r rhwydwaith">
+<!ENTITY captivePortal.longDesc2 "<p>Rhaid i chi fewngofnodi i'r rhwydwaith hwn cyn i chi gael mynediad i'r Rhyngrwyd.</p>">
+
+<!ENTITY openPortalLoginPage.label2 "Agor Tudalen Mewngofnodi i'r Rhwydwaith">
+
+<!ENTITY malformedURI.pageTitle "URL annilys">
+
+<!ENTITY netInterrupt.longDesc "&sharedLongDesc;">
+
+<!ENTITY notCached.longDesc "<p>Nid yw'r ddogfen gofynnwyd amdani ar gael yn storfa dros dro &brandShortName;.</p><ul><li>Fel cam i sicrhau diogelwch nid yw &brandShortName; yn gofyn eto am ddogfennau sensitif.</li><li>Cliciwch Ceisio Eto i ofyn eto am y ddogfen o'r wefan.</li></ul>">
+
+<!ENTITY netOffline.longDesc2 "<ul> <li>Clicio &quot;Ceisio newid eto&quot; i newid i&apos;r modd ar-lein ac ail lwytho'r dudalen.</li> </ul>">
+
+<!ENTITY contentEncodingError.longDesc "<ul> <li>Cysylltwch â pherchnogion y wefan i'w hysbysu o'r anhawster.</li> </ul>">
+
+<!ENTITY unsafeContentType.longDesc "<ul> <li>Cysylltwch â pherchnogion y wefan i'w hysbysu o'r anhawster.</li> </ul>">
+
+<!ENTITY netReset.longDesc "&sharedLongDesc;">
+
+<!ENTITY netTimeout.longDesc "&sharedLongDesc;">
+
+<!ENTITY unknownProtocolFound.longDesc "<ul> <li>Efallai bydd angen i chi osod meddalwedd arall i agor y cyfeiriad yma.</li> </ul>">
+
+<!ENTITY proxyConnectFailure.longDesc "<ul> <li>Gwiriwch osodiadau'r dirprwy i wneud yn siŵr eu bod yn gywir.</li> <li>Cysylltwch â'ch gweinyddwr system i wneud yn siŵr fod y gweinydd dirprwyol yn gweithio.</li> </ul>">
+
+<!ENTITY proxyResolveFailure.longDesc "<ul> <li>Gwiriwch y gosodiadau dirprwyol i wneud yn siŵr eu bod yn gywir.</li> <li>Gwiriwch fod gan eich cyfrifiadur cyswllt a'r we sy'n gweithio.</li> <li>Os yw eich cyfrifiadur wedi ei ddiogelu gan fur cadarn neu ddirprwy, gwnewch yn siŵr fod gan &brandShortName; fynediad i'r we.</li> </ul>">
+
+<!ENTITY redirectLoop.longDesc "<ul> <li>Gall y broblem yma fod wedi ei hachosi drwy analluogi neu wrthod cwci.</li> </ul>">
+
+<!ENTITY unknownSocketType.longDesc "<ul> <li>Gwiriwch fod gan eich system Reolwr Diogelwch Personol wedi ei osod.</li> <li>Gall hyn fod oherwydd ffurfweddiad ansafonol ar y gweinydd.</li> </ul>">
+
+<!ENTITY nssFailure2.longDesc2 "<ul> <li>Nid oes modd dangos y dudalen rydych yn ceisio ei darllen am nad oes modd dilysu'r data rydych wedi ei dderbyn.</li> <li>Cysylltwch â pherchnogion y wefan i'w hysbysu o'r anhawster.</li> </ul>">
+
+<!-- Localization note (certerror.introPara2) - The text content of the span tag
+will be replaced at runtime with the name of the server to which the user
+was trying to connect. -->
+<!ENTITY certerror.introPara2 "Mae &brandShortName; wedi canfod bygythiad diogelwch posib ac nid yw wedi mynd i <span class='hostname'/>. Os ewch i'r gwefan yma, gall ymosodwyr geisio dwyn gwybodaeth fel eich cyfrineiriau, e-byst neu fanylion cardiau credyd.">
+<!ENTITY certerror.sts.introPara "Mae &brandShortName; wedi canfod bygythiad diogelwch posib ac nid yw wedi mynd i <span class='hostname'/> gan fod y wefan angen cysylltiad diogel.">
+
+<!ENTITY certerror.expiredCert.introPara "Mae &brandShortName; wedi canfod bygythiad diogelwch posib ac nid yw wedi mynd i <span class='hostname'/>. Un ai mae'r wefan wedi ei gam ffurfweddu neu mae cloc eich cyfrifiadur wedi ei osod i'r amser anghywir.">
+<!ENTITY certerror.expiredCert.secondPara2 "Mae'n debyg fod tystysgrif y wefan wedi dod i ben, sy'n atal &brandShortName; rhag cysylltu'n ddiogell. Os ewch chi i'r wefan hon gall ymosodwyr geisio dwy gwybodaeth fel eich cyfrineiriau, e-byst neu fanylion cerdyn credyd.">
+<!ENTITY certerror.expiredCert.sts.secondPara "Mae'n debyg fod tystysgrif y wefan wedi dod i ben, sy'n atal &brandShortName; rhag cysylltu'n ddiogell.">
+
+<!ENTITY certerror.whatCanYouDoAboutItTitle "Beth allwch chi wneud am hyn?">
+
+<!ENTITY certerror.unknownIssuer.whatCanYouDoAboutIt "<p>Mae hyn yn fater i'r wefan a does dim fedrwch chi wneud am y peth.</p>
+<p>Os ydych chi ar rwydwaith corfforaethol neu yn defnyddio meddalwedd gwrth-firws gallwch ofyn i'r timau cefnogi am gymorth. Gallwch hefyd hysbysu gweinyddwr y wefan am y broblem.</p>">
+
+<!ENTITY certerror.expiredCert.whatCanYouDoAboutIt2 "<p>Mae cloc eich cyfrifiadur wedi ei osod i <span id='wrongSystemTime_systemDate2'/>. Gwnewch yn siŵr fod y dyddiad, amser a chylch amser yn gywir yn eich gosodiadau system ac yna adnewyddu <span class='hostname'/>.</p>
+<p>Os yw eich cloc eisoes wedi ei osod i'r amser cywir, mwy na thebyg mae'r wefan wedi ei gam osod a does dim fedrwch chi ei wneud i ddatrys y broblem. Gallwch hysbysu gweinyddwr y wefan am y broblem.</p>">
+
+<!ENTITY certerror.badCertDomain.whatCanYouDoAboutIt "<p>Mae'n fater i'r wefan a does dim fedrwch chi wneud i ddatrys y mater. Gallwch hysbysu gweinyddwr y wefan am y broblem.</p>">
+
+<!ENTITY sharedLongDesc "<ul> <li>Efallai bod y wefan yn brysur neu nad yw ar gael dros dro. Ceisiwch eto ymhen ychydig.</li> <li>Os nad ydych yn gallu llwytho unrhyw dudalennau, gwiriwch gysylltiad rhwydwaith eich cyfrifiadur.</li> <li>Os yw eich cyfrifiadur neu rwydwaith wedi ei ddiogelu gan fur cadarn neu ddirprwy, gwnewch yn siŵr fod gan &brandShortName; hawl i fynediad i'r we.</li> </ul>">
+
+<!ENTITY cspBlocked.longDesc "<p>Mae &brandShortName; wedi rhwystro'r dudalen rhag llwytho yn y ffordd yma gan fod gan y dudalen bolisi diogelwch cynnwys sy'n atal hynny.</p>">
+
+<!ENTITY xfoBlocked.longDesc "<p>Mae &brandShortName; wedi atal y dudalen hon rhag llwytho yn y cyd-destun hwn oherwydd bod gan y dudalen bolisi X-Frame-Options sy'n ei gwrthod.</p>">
+
+<!ENTITY corruptedContentErrorv2.longDesc "<p>Nid oes modd dangos y dudalen rydych yn ceisio ei gweld yn sgil canfod gwall trosglwyddo data.</p><ul><li>Cysylltwch â pherchnogion y wefan i'w hysbysu o'r anhawster.</li></ul>">
+
+<!ENTITY securityOverride.exceptionButton1Label "Derbyn y Bygythiad a Pharhau">
+
+<!ENTITY errorReporting.automatic2 "Mae adroddiadau gwall fel hyn y cynorthwyo Mozilla i adnabod a rhwystro gwefannau maleisus">
+<!ENTITY errorReporting.learnMore "Dysgu rhagor…">
+
+<!-- LOCALIZATION NOTE (sslv3Used.longDesc2) - Do not translate
+     "SSL_ERROR_UNSUPPORTED_VERSION". -->
+<!ENTITY sslv3Used.longDesc2 "Gwybodaeth uwch: SSL_ERROR_UNSUPPORTED_VERSION">
+
+<!ENTITY certerror.pagetitle2  "Rhybudd: Risg Diogelwch Posibl o'ch Blaen">
+<!ENTITY certerror.sts.pagetitle  "Peidiwch cysylltu: Mater Diogelwch Posib">
+<!ENTITY certerror.whatShouldIDo.badStsCertExplanation1 "Mae gan <span class='hostname'></span> bolisi diogelwch o'r enw HTTP Strict Transport Security (HSTS), sy'n golygu mai dim ond yn ddiogel mae modd i &brandShortName; gysylltu. Nid oes modd gosod eithriad er mwyn ymweld â'r wefan.">
+<!ENTITY certerror.copyToClipboard.label "Copïo testun i'r clipfwrdd">
+
+<!-- LOCALIZATION NOTE (inadequateSecurityError.longDesc) - Do not translate
+     "NS_ERROR_NET_INADEQUATE_SECURITY". -->
+<!ENTITY inadequateSecurityError.longDesc "Mae <p><span class='hostname'></span> yn defnyddio technoleg diogelwch sy'n hen ac yn agored i ymosodiad. Gall yr ymosodwr weld manylion am hyn roeddech yn meddwl ei fod yn ddiogel. Mae angen i weinyddwr y wefan drwsio'r gweinydd yn gyntaf cyn bod modd i chi ymweld â' r wefan.</p><p>Cod gwall: NS_ERROR_NET_INADEQUATE_SECURITY</p>">
+
+<!ENTITY blockedByPolicy.title "Tudalen wedi'i Rhwystro">
+
+<!ENTITY certerror.mitm.longDesc "Mae <span class='hostname'></span> mwy na thebyg yn wefan diogel, ond nid oedd modd sefydlu cysylltiad diogel. Achoswyd hyn gan <span class='mitm-name'/>, sy'n un a'i feddalwedd ar eich cyfrifiadur neu rwydwaith.">
+<!ENTITY certerror.mitm.whatCanYouDoAboutIt1 "Os yw eich meddalwedd gwrth-firws yn cynnwys nodwedd sy'n sganio cysylltiadau wedi eu hamgryptio (“web scanning” neu “https scanning”), gallwch analluogu'r nodwedd honno. Os nad yw hynny'n gweithio, gallwch dynnu ac ailosod y feddalwedd gwrth-firws.">
+<!ENTITY certerror.mitm.whatCanYouDoAboutIt2 "Os ydych ar rwydwaith corfforaethol, cysylltwch a'ch adran TG.">
+<!ENTITY certerror.mitm.whatCanYouDoAboutIt3 "Os nad ydych yn gyfarwydd â <span class='mitm-name'/>, yna gall hyn fod yn ymosodiad ac ni ddylech barhau ar y wefan hon.">
+<!ENTITY certerror.mitm.sts.whatCanYouDoAboutIt3 "Os nad ydych yn gyfarwydd â <span class='mitm-name'/>, yna gall hyn fod yn ymosodiad ac nid oes dim y gallwch ei wneud i gael mynediad i'r wefan.">
+
+<!ENTITY clockSkewError.longDesc "Mae eich cyfrifiadur yn meddwl ei bod hi'n <span id='wrongSystemTime_systemDate1'/>, sy'n rhwystro &brandShortName; rhag cysylltu'n ddiogel. I fynd i <span class='hostname'></span>, diweddarwch gloc eich cyfrifiadur yng ngosodiadau eich system i'r dyddiad, amser a chylch amser cyfredol ac yna adnewyddu <span class='hostname'></span>.">
+
+<!ENTITY prefReset.longDesc "Mae'n edrych fel mai eich gosodiadau diogelwch rhwydwaith sy'n achosi hyn. Hoffech chi adfer y gosodiadau rhagosodedig?">
+<!ENTITY prefReset.label "Adfer y gosodiadau rhagosodedig">
+
+<!ENTITY networkProtocolError.longDesc "<p>Nid oes modd dangos y dudalen rydych yn ceisio'i gweld oherwydd cafwyd gwall yn y protocol rhwydwaith.</p><ul><li>Cysylltwch â pherchenogion y wefan i roi gwybod iddynt am y broblem hon.</li></ul>">
diff --git a/l10n-cy/browser/crashreporter/crashreporter-override.ini b/l10n-cy/browser/crashreporter/crashreporter-override.ini
new file mode 100644
index 0000000000..32bd685383
--- /dev/null
+++ b/l10n-cy/browser/crashreporter/crashreporter-override.ini
@@ -0,0 +1,8 @@
+; This Source Code Form is subject to the terms of the Mozilla Public
+; License, v. 2.0. If a copy of the MPL was not distributed with this
+; file, You can obtain one at http://mozilla.org/MPL/2.0/.
+; This file is in the UTF-8 encoding
+[Strings]
+; LOCALIZATION NOTE (CrashReporterProductErrorText2): The %s is replaced with a string containing detailed information.
+CrashReporterProductErrorText2=Profodd Firefox anhawster a chwalodd. Byddwn yn ceisio adfer eich tabiau a ffenestri pan fydd yn ailgychwyn.\n\nYn anffodus, nid yw'r adroddwr chwalfa'n gallu cyflwyno adroddiad chwalu.\n\nManylion: %s
+CrashReporterDescriptionText2=Profodd Firefox anhawster a chwalodd. Byddwn yn ceisio adfer eich tabiau a ffenestri pan fydd yn ailgychwyn.\n\nI'n cynorthwyo i ddadansoddi a chywiro'r broblem, anfonwch adroddiad chwalu atom.
diff --git a/l10n-cy/browser/defaultagent/defaultagent_localized.ini b/l10n-cy/browser/defaultagent/defaultagent_localized.ini
new file mode 100644
index 0000000000..166c7f72c5
--- /dev/null
+++ b/l10n-cy/browser/defaultagent/defaultagent_localized.ini
@@ -0,0 +1,12 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# This file is in the UTF-8 encoding
+[Strings]
+DefaultBrowserAgentTaskDescription=Mae tasgau Asiant Porwr Rhagosodedig yn gwirio pan fydd y rhagosodiad yn newid o %MOZ_APP_DISPLAYNAME% i borwr arall. Os bydd y newid yn digwydd o dan amgylchiadau amheus, bydd yn annog defnyddwyr i newid yn ôl i %MOZ_APP_DISPLAYNAME% ddim mwy na dwywaith. Mae'r dasg hon yn cael ei gosod yn awtomatig gan %MOZ_APP_DISPLAYNAME%, ac mae'n cael ei hailosod pan fydd %MOZ_APP_DISPLAYNAME% yn diweddaru. I analluogi'r dasg hon, diweddarwch y dewis "default-browser-agent.enabled" ar y dudalen about:config neu'r gosodiad polisi menter %MOZ_APP_DISPLAYNAME% "DisableDefaultBrowserAgent".
+
+DefaultBrowserNotificationTitle=Gwnewch %MOZ_APP_DISPLAYNAME% yn eich porwr rhagosodedig
+DefaultBrowserNotificationText=Nid %MOZ_APP_DISPLAYNAME% bellach yn eich porwr rhagosodedig. Ei wneud yn ragosodedig?
+DefaultBrowserNotificationYesButtonText=Iawn
+DefaultBrowserNotificationNoButtonText=Na
diff --git a/l10n-cy/browser/defines.inc b/l10n-cy/browser/defines.inc
new file mode 100644
index 0000000000..adeee3f2e2
--- /dev/null
+++ b/l10n-cy/browser/defines.inc
@@ -0,0 +1,14 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+#filter emptyLines
+
+#define MOZ_LANGPACK_CREATOR mozilla.org
+
+# If non-English locales wish to credit multiple contributors, uncomment this
+
+# variable definition and use the format specified.
+
+#define MOZ_LANGPACK_CONTRIBUTORS <em:contributor>Rhoslyn Prys</em:contributor> <em:contributor>David Chan</em:contributor> <em:contributor>Dewi B. Jones</em:contributor>
+
+#unfilter emptyLines
diff --git a/l10n-cy/browser/extensions/formautofill/formautofill.properties b/l10n-cy/browser/extensions/formautofill/formautofill.properties
new file mode 100644
index 0000000000..75807e3d6f
--- /dev/null
+++ b/l10n-cy/browser/extensions/formautofill/formautofill.properties
@@ -0,0 +1,231 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# LOCALIZATION NOTE (saveAddressesMessage): %S is brandShortName. This string is used on the doorhanger to
+# notify users that addresses are saved.
+saveAddressesMessage = Mae %S nawr yn cadw cyfeiriadau fel bod modd i chi lanw ffurflenni'n gynt.
+# LOCALIZATION NOTE (autofillOptionsLink, autofillOptionsLinkOSX): These strings are used in the doorhanger for
+# updating addresses. The link leads users to Form Autofill browser preferences.
+autofillOptionsLink = Opsiynau Awtolanw Ffurflenni
+autofillOptionsLinkOSX = Dewisiadau Awtolanw Ffurflenni
+# LOCALIZATION NOTE (changeAutofillOptions, changeAutofillOptionsOSX): These strings are used on the doorhanger
+# that notifies users that addresses are saved. The button leads users to Form Autofill browser preferences.
+changeAutofillOptions = Newid Opsiynau Awtolanw Ffurflenni
+changeAutofillOptionsOSX = Newid Dewisiadau Awtolanw Ffurflenni
+changeAutofillOptionsAccessKey = O
+# LOCALIZATION NOTE (addressesSyncCheckbox): If Sync is enabled, this checkbox is displayed on the doorhanger
+# shown when saving addresses.
+addressesSyncCheckbox = Rhannu cyfeiriadau gyda dyfeisiau sydd wedi eu cydweddu
+# LOCALIZATION NOTE (creditCardsSyncCheckbox): If Sync is enabled and credit card sync is available,
+# this checkbox is displayed on the doorhanger shown when saving credit card.
+creditCardsSyncCheckbox = Rhannu cardiau credyd gyda dyfeisiau wedi eu cydweddu
+# LOCALIZATION NOTE (updateAddressMessage, updateAddressDescriptionLabel, createAddressLabel, updateAddressLabel):
+# Used on the doorhanger when an address change is detected.
+updateAddressMessage = Hoffech chi ddiweddaru eich cyfeiriad gyda'r wybodaeth newydd hwn?
+updateAddressDescriptionLabel = Cyfeiriad i'w ddiweddaru:
+createAddressLabel = Creu Cyfeiriad Newydd
+createAddressAccessKey = C
+updateAddressLabel = Diweddaru Cyfeiriad
+updateAddressAccessKey = D
+# LOCALIZATION NOTE (saveCreditCardMessage, saveCreditCardDescriptionLabel, saveCreditCardLabel, cancelCreditCardLabel, neverSaveCreditCardLabel):
+# Used on the doorhanger when users submit payment with credit card.
+# LOCALIZATION NOTE (saveCreditCardMessage): %S is brandShortName.
+saveCreditCardMessage = Hoffech chi i %S gadw'r cerdyn credyd hwn? (Ni fydd y cod diogelwch y cael ei gadw)
+saveCreditCardDescriptionLabel = Cerdyn credyd i'w gadw:
+saveCreditCardLabel = Cadw Cerdyn Credyd
+saveCreditCardAccessKey = e
+cancelCreditCardLabel = Peidio â Chadw
+cancelCreditCardAccessKey = D
+neverSaveCreditCardLabel = Peidio Byth a Chadw Cerdyn Credyd
+neverSaveCreditCardAccessKey = P
+# LOCALIZATION NOTE (updateCreditCardMessage, updateCreditCardDescriptionLabel, createCreditCardLabel, updateCreditCardLabel):
+# Used on the doorhanger when an credit card change is detected.
+updateCreditCardMessage = Hoffech chi ddiweddaru eich cerdyn credyd gyda'r manylion newydd?
+updateCreditCardDescriptionLabel = Cerdyn credyd i'e ddiweddaru:
+createCreditCardLabel = Creu Cerdyn Credyd Newydd
+createCreditCardAccessKey = C
+updateCreditCardLabel = Diweddaru Cerdyn Credyd
+updateCreditCardAccessKey = D
+# LOCALIZATION NOTE (openAutofillMessagePanel): Tooltip label for Form Autofill doorhanger icon on address bar.
+openAutofillMessagePanel = Agor panel neges Awtolanw Ffurflenni
+
+# LOCALIZATION NOTE (autocompleteFooterOption2):
+# Used as a label for the button, displayed at the bottom of the dropdown suggestion, to open Form Autofill browser preferences.
+autocompleteFooterOption2 = Dewisiadau Awtolanw Ffurflenni
+# LOCALIZATION NOTE (autocompleteFooterOptionOSX2):
+# Used as a label for the button, displayed at the bottom of the dropdown suggestion, to open Form Autofill browser preferences.
+autocompleteFooterOptionOSX2 = Dewisiadau Awtolanw Ffurflenni
+# LOCALIZATION NOTE (autocompleteFooterOptionShort2):
+# Used as a label for the button, displayed at the bottom of the dropdown suggestion, to open Form Autofill browser preferences.
+# The short version is used for inputs below a certain width (e.g. 150px).
+autocompleteFooterOptionShort2 = Opsiynau Awtolanw Ffurflenni
+# LOCALIZATION NOTE (autocompleteFooterOptionOSXShort2):
+# Used as a label for the button, displayed at the bottom of the dropdown suggestion, to open Form Autofill browser preferences.
+# The short version is used for inputs below a certain width (e.g. 150px).
+autocompleteFooterOptionOSXShort2 = Dewisiadau Awtolanw Ffurflenni
+# LOCALIZATION NOTE (category.address, category.name, category.organization2, category.tel, category.email):
+# Used in autofill drop down suggestion to indicate what other categories Form Autofill will attempt to fill.
+category.address = cyfeiriad
+category.name = enw
+category.organization2 = corff
+category.tel = ffôn
+category.email = e-bost
+# LOCALIZATION NOTE (fieldNameSeparator): This is used as a separator between categories.
+fieldNameSeparator = ,\u0020
+# LOCALIZATION NOTE (phishingWarningMessage, phishingWarningMessage2): The warning
+# text that is displayed for informing users what categories are about to be filled.
+# "%S" will be replaced with a list generated from the pre-defined categories.
+# The text would be e.g. Also autofills organization, phone, email.
+phishingWarningMessage = Hefyd yn awtolanw %S
+phishingWarningMessage2 = Awtolanw %S
+# LOCALIZATION NOTE (insecureFieldWarningDescription): %S is brandShortName. This string is used in drop down
+# suggestion when users try to autofill credit card on an insecure website (without https).
+insecureFieldWarningDescription = Mae %S wedi canfod gwefan anniogel. Mae Awtolanw Ffurflenni wedi ei analluogi dos dro
+# LOCALIZATION NOTE (clearFormBtnLabel2): Label for the button in the dropdown menu that used to clear the populated
+# form.
+clearFormBtnLabel2 = Gwagio'r Ffurflen Awtolanw
+
+autofillHeader = Ffurflenni ac Awtolanw
+# LOCALIZATION NOTE (autofillAddressesCheckbox): Label for the checkbox that enables autofilling addresses.
+autofillAddressesCheckbox = Awtolanw cyfeiriadau
+# LOCALIZATION NOTE (learnMoreLabel): Label for the link that leads users to the Form Autofill SUMO page.
+learnMoreLabel = Dysgu rhagor
+# LOCALIZATION NOTE (savedAddressesBtnLabel): Label for the button that opens a dialog that shows the
+# list of saved addresses.
+savedAddressesBtnLabel = Cyfeiriadau wedi eu Cadw…
+# LOCALIZATION NOTE (autofillCreditCardsCheckbox): Label for the checkbox that enables autofilling credit cards.
+autofillCreditCardsCheckbox = Awtolanw cardiau credyd
+# LOCALIZATION NOTE (savedCreditCardsBtnLabel): Label for the button that opens a dialog that shows the list
+# of saved credit cards.
+savedCreditCardsBtnLabel = Cardiau Credyd wedi eu Cadw…
+
+autofillReauthCheckboxMac = Gofyn i macOS ddilysu cyn awtolanw, gweld, neu olygu cardiau credyd sydd wedi'u storio.
+autofillReauthCheckboxWin = Gofyn i Windows i ddilysu cyn awtolanw, gweld, neu olygu cardiau credyd sydd wedi'u storio.
+autofillReauthCheckboxLin = Gofyn i Linux ddilysu cyn awtolanw, gweld, neu olygu cardiau credyd sydd wedi'u storio.
+
+# LOCALIZATION NOTE (autofillReauthOSDialogMac): This string is
+# preceded by the operating system (macOS) with "Firefox is trying to ", and
+# has a period added to its end. Make sure to test in your locale.
+autofillReauthOSDialogMac = newid y gosodiadau dilysu
+autofillReauthOSDialogWin = I newid y gosodiadau dilysu, rhowch eich manylion mewngofnodi Windows.
+autofillReauthOSDialogLin = I newid y gosodiadau dilysu, rhowch eich manylion mewngofnodi Linux.
+
+# LOCALIZATION NOTE (manageAddressesTitle, manageCreditCardsTitle): The dialog title for the list of addresses or
+# credit cards in browser preferences.
+manageAddressesTitle = Cyfeiriadau wedi eu Cadw
+manageCreditCardsTitle = Cardiau Credyd wedi eu Cadw
+# LOCALIZATION NOTE (addressesListHeader, creditCardsListHeader): The header for the list of addresses or credit cards
+# in browser preferences.
+addressesListHeader = Cyfeiriadau
+creditCardsListHeader = Cardiau Credyd
+removeBtnLabel = Tynnu
+addBtnLabel = Ychwanegu…
+editBtnLabel = Golygu…
+# LOCALIZATION NOTE (manageDialogsWidth): This strings sets the default width for windows used to manage addresses and
+# credit cards.
+manageDialogsWidth = 560px
+
+# LOCALIZATION NOTE (addNewAddressTitle, editAddressTitle): The dialog title for creating or editing addresses
+# in browser preferences.
+addNewAddressTitle = Ychwanegu Cyfeiriad Newydd
+editAddressTitle = Golygu Cyfeiriad
+givenName = Enw Cyntaf
+additionalName = Enw Canol
+familyName = Enw Olaf
+organization2 = Corff
+streetAddress = Cyfeiriad Stryd
+
+## address-level-3 (Sublocality) names
+# LOCALIZATION NOTE (neighborhood): Used in IR, MX
+neighborhood = Cymdogaeth
+# LOCALIZATION NOTE (village_township): Used in MY
+village_township = Pentref eu Dref
+island = Ynys
+# LOCALIZATION NOTE (townland): Used in IE
+townland = Tref
+
+## address-level-2 names
+city = Tref/Dinas
+# LOCALIZATION NOTE (district): Used in HK, SD, SY, TR as Address Level-2
+# and used in KR as Sublocality.
+district = Ardal
+# LOCALIZATION NOTE (post_town): Used in GB, NO, SE
+post_town = Tref post
+# LOCALIZATION NOTE (suburb): Used in AU as Address Level-2
+# and used in ZZ as Sublocality.
+suburb = Maestref
+
+# address-level-1 names
+province = Ardal/Talaith
+state = Sir
+county = Sir
+# LOCALIZATION NOTE (parish): Used in BB, JM
+parish = Plwyf
+# LOCALIZATION NOTE (prefecture): Used in JP
+prefecture = Rhaglawiaeth
+# LOCALIZATION NOTE (area): Used in HK
+area = Ardal
+# LOCALIZATION NOTE (do_si): Used in KR
+do_si = Do/Si
+# LOCALIZATION NOTE (department): Used in NI, CO
+department = Adran
+# LOCALIZATION NOTE (emirate): Used in AE
+emirate = Emirad
+# LOCALIZATION NOTE (oblast): Used in RU and UA
+oblast = Oblast
+
+# LOCALIZATION NOTE (pin, postalCode, zip, eircode): Postal code name types
+# LOCALIZATION NOTE (pin): Used in IN
+pin = Pin
+postalCode = Cod Post
+zip = Cod Zip
+# LOCALIZATION NOTE (eircode): Used in IE
+eircode = Eircode
+
+country = Gwlad neu Ranbarth
+tel = Ffôn
+email = E-bost
+cancelBtnLabel = Diddymu
+saveBtnLabel = Cadw
+countryWarningMessage2 = Dim ond ar gyfer rhai gwledydd y mae Awtolanw Ffurflenni ar gael ar hyn o bryd.
+
+# LOCALIZATION NOTE (addNewCreditCardTitle, editCreditCardTitle): The dialog title for creating or editing
+# credit cards in browser preferences.
+addNewCreditCardTitle = Ychwanegu Cerdyn Credyd Newydd
+editCreditCardTitle = Golygu Cerdyn Credyd
+cardNumber = Rhif y Cerdyn
+invalidCardNumber = Rhowch rif cerdyn dilys
+nameOnCard = Enw ar y Cerdyn
+cardExpiresMonth = Mis Dod i Ben
+cardExpiresYear = Blwyddyn Daw i Ben
+billingAddress = Cyfeiriad Archebion
+cardNetwork = Mathau o Gerdyn
+# LOCALIZATION NOTE (cardCVV): Credit card security code https://en.wikipedia.org/wiki/Card_security_code
+cardCVV = CVV
+
+# LOCALIZATION NOTE: (cardNetwork.*): These are brand names and should only be translated when a locale-specific name for that brand is in common use
+cardNetwork.amex = American Express
+cardNetwork.cartebancaire = Carte Bancaire
+cardNetwork.diners = Diners Club
+cardNetwork.discover = Discover
+cardNetwork.jcb = JCB
+cardNetwork.mastercard = MasterCard
+cardNetwork.mir = MIR
+cardNetwork.unionpay = Union Pay
+cardNetwork.visa = Visa
+
+# LOCALIZATION NOTE (editCreditCardPasswordPrompt.*, useCreditCardPasswordPrompt.*): %S is brandShortName.
+editCreditCardPasswordPrompt.win = Mae %S yn ceisio dangos manylion cerdyn credyd. Cadarnhewch fynediad i'r cyfrif Windows hwn isod.
+# LOCALIZATION NOTE (editCreditCardPasswordPrompt.macos): This string is
+# preceded by the operating system (macOS) with "Firefox is trying to ", and
+# has a period added to its end. Make sure to test in your locale.
+editCreditCardPasswordPrompt.macos = dangos manylion cerdyn credyd
+editCreditCardPasswordPrompt.linux = Mae %S yn ceisio dangos manylion cerdyn credyd.
+
+useCreditCardPasswordPrompt.win = Mae %S yn ceisio dangos manylion cerdyn credyd. Cadarnhewch fynediad i'r cyfrif Windows hwn isod.
+# LOCALIZATION NOTE (useCreditCardPasswordPrompt.macos): This string is
+# preceded by the operating system (macOS) with "Firefox is trying to ", and
+# has a period added to its end. Make sure to test in your locale.
+useCreditCardPasswordPrompt.macos = defnyddio manylion cerdyn credyd wedi'i storio
+useCreditCardPasswordPrompt.linux = Mae %S yn ceisio defnyddio manylion cerdyn credyd wedi ei gadw.
diff --git a/l10n-cy/browser/extensions/report-site-issue/webcompat.properties b/l10n-cy/browser/extensions/report-site-issue/webcompat.properties
new file mode 100644
index 0000000000..048c8e7496
--- /dev/null
+++ b/l10n-cy/browser/extensions/report-site-issue/webcompat.properties
@@ -0,0 +1,10 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# LOCALIZATION NOTE(wc-reporter.label2): This string will be used in the
+# Firefox page actions menu. Localized length should be considered.
+wc-reporter.label2=Adrodd ar Fater Gwefan…
+# LOCALIZATION NOTE(wc-reporter.tooltip): A site compatibility issue is
+# a website bug that exists in one browser (Firefox), but not another.
+wc-reporter.tooltip=Adrodd ar fater cydnawsedd gwefan
diff --git a/l10n-cy/browser/firefox-l10n.js b/l10n-cy/browser/firefox-l10n.js
new file mode 100644
index 0000000000..b410ad9aef
--- /dev/null
+++ b/l10n-cy/browser/firefox-l10n.js
@@ -0,0 +1,6 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+#filter substitution
+
diff --git a/l10n-cy/browser/installer/custom.properties b/l10n-cy/browser/installer/custom.properties
new file mode 100644
index 0000000000..4ae25e98b4
--- /dev/null
+++ b/l10n-cy/browser/installer/custom.properties
@@ -0,0 +1,94 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# LOCALIZATION NOTE:
+
+# This file must be saved as UTF8
+
+# Accesskeys are defined by prefixing the letter that is to be used for the
+# accesskey with an ampersand (e.g. &).
+
+# Do not replace $BrandShortName, $BrandFullName, or $BrandFullNameDA with a
+# custom string and always use the same one as used by the en-US files.
+# $BrandFullNameDA allows the string to contain an ampersand (e.g. DA stands
+# for double ampersand) and prevents the letter following the ampersand from
+# being used as an accesskey.
+
+# You can use \n to create a newline in the string but only when the string
+# from en-US contains a \n.
+
+REG_APP_DESC=Mae $BrandShortName yn cynnig pori gwe hawdd a diogel. Rhyngwyneb cyfarwydd, nodweddion diogelwch uwch yn cynnwys diogelwch rhag lladrad hunaniaeth ar-lein a chwilio integredig i gael y mwyaf allan o'r we.
+PRIVATE_BROWSING_SHORTCUT_TITLE=Pori Preifat $BrandShortName
+CONTEXT_OPTIONS=&Dewisiadau $BrandShortName
+CONTEXT_SAFE_MODE=&Modd Diogel $BrandShortName
+OPTIONS_PAGE_TITLE=Math o Osod
+OPTIONS_PAGE_SUBTITLE=Dewisiadau gosod
+SHORTCUTS_PAGE_TITLE=Llwybrau Byr y Gosod
+SHORTCUTS_PAGE_SUBTITLE=Creu Eiconau'r Rhaglen
+COMPONENTS_PAGE_TITLE=Gosod Cydrannau Ychwanegol
+COMPONENTS_PAGE_SUBTITLE=Cydrannau Dewisol Cymeradwy
+OPTIONAL_COMPONENTS_DESC=Bydd y Gwasanaeth Cynnal yn caniatáu i chi ddiweddaru $BrandShortName yn dawel yn y cefndir.
+MAINTENANCE_SERVICE_CHECKBOX_DESC=Gosod y &Gwasanaeth Cynnal
+SUMMARY_PAGE_TITLE=Crynodeb
+SUMMARY_PAGE_SUBTITLE=Yn barod i osod $BrandShortName
+SUMMARY_INSTALLED_TO=Bydd $BrandShortName yn cael ei osod yn y lleoliad canlynol:
+SUMMARY_REBOOT_REQUIRED_INSTALL=Efallai bydd angen ailgychwyn y cyfrifiadur er mwyn cwblhau'r gosod.
+SUMMARY_REBOOT_REQUIRED_UNINSTALL=Efallai bydd angen ailgychwyn y cyfrifiadur er mwyn cwblhau'r dadosod.
+SUMMARY_TAKE_DEFAULTS=&Defnyddio $BrandShortName fel y porwr rhagosodedig
+SUMMARY_INSTALL_CLICK=Clicio Gosod i barhau.
+SUMMARY_UPGRADE_CLICK=Clicio Diweddaru i barhau.
+SURVEY_TEXT=Dweud wr&thym eich barn am $BrandShortName
+LAUNCH_TEXT=&Cychwyn $BrandShortName nawr
+CREATE_ICONS_DESC=Creu eiconau $BrandShortName:
+ICONS_DESKTOP=Ar y &Bwrdd Gwaith
+ICONS_STARTMENU=Yn ffolder &Rhaglenni Dewislen Cychwyn
+ICONS_QUICKLAUNCH=Yn y bar &Cychwyn Cyflym
+ICONS_TASKBAR=Ar fy &mar tasgau
+WARN_MANUALLY_CLOSE_APP_INSTALL=Rhaid cau $BrandShortName er mwyn parhau gyda'r gosod.\n\nCaewch $BrandShortName er mwyn parhau.
+WARN_MANUALLY_CLOSE_APP_UNINSTALL=Rhaid cau $BrandShortName er mwyn parhau gyda'r dadosod.\n\nCaewch $BrandShortName er mwyn parhau.
+WARN_MANUALLY_CLOSE_APP_REFRESH=Rhaid fod $BrandShortName ar gau i barhau gyda'r adnewyddu.\n \n Caewch $BrandShortName i barhau.
+WARN_WRITE_ACCESS=Nid oes gennych fynediad i ysgrifennu i'r cyfeiriadur gosod.\n\nCliciwch Iawn i ddewis cyfeiriadur gwahanol.
+WARN_DISK_SPACE=Nid oes gennych ddigon o le ar ddisg i osod yn y lleoliad hwn.\n\nCliciwch Iawn i ddewis lleoliad gwahanol.
+WARN_MIN_SUPPORTED_OSVER_MSG=Ymddiheuriadau, nid oes modd gosod $BrandShortName. Mae'r fersiwn hwn o $BrandShortName angen ${MinSupportedVer} neu fwy diweddar. Cliciwch ar y botwm Iawn am wybodaeth bellach.
+WARN_MIN_SUPPORTED_CPU_MSG=Ymddiheuriadau, nid oes modd gosod $BrandShortName. Mae'r fersiwn hwn o $BrandShortName angen ${MinSupportedCPU} neu fwy diweddar. Cliciwch ar y botwm Iawn am wybodaeth bellach.
+WARN_MIN_SUPPORTED_OSVER_CPU_MSG=Ymddiheuriadau, nid oes modd gosod $BrandShortName. Mae'r fersiwn hwn o $BrandShortName angen ${MinSupportedVer} a phrosesydd gyda chefnogaeth ar gyfer ${MinSupportedCPU}. Cliciwch ar y botwm Iawn am wybodaeth bellach.
+WARN_RESTART_REQUIRED_UNINSTALL=Rhaid ailgychwyn y cyfrifiadur er mwyn cwblhau dadosod y fersiwn diwethaf o $BrandShortName. Hoffech chi ailgychwyn nawr?
+WARN_RESTART_REQUIRED_UPGRADE=Rhaid ailgychwyn y cyfrifiadur er mwyn cwblhau'r diweddariad diwethaf o $BrandShortName. Hoffech chi ailgychwyn nawr?
+ERROR_CREATE_DIRECTORY_PREFIX=Gwall wrth greu cyfeiriadur:
+ERROR_CREATE_DIRECTORY_SUFFIX=Cliciwch Diddymu i atal gosod neu\nEto er mwyn ceisio eto.
+
+UN_CONFIRM_PAGE_TITLE=Dad-osod $BrandFullName
+UN_CONFIRM_PAGE_SUBTITLE=Tynnu $BrandFullName oddi ar eich cyfrifiadur.
+UN_CONFIRM_UNINSTALLED_FROM=Bydd $BrandShortName yn cael ei ddadosod o'r ffolder canlynol:
+UN_CONFIRM_CLICK=Clicio Dadosod i barhau.
+
+UN_REFRESH_PAGE_TITLE=Adnewyddu $BrandShortName yn lle hynny?
+UN_REFRESH_PAGE_EXPLANATION=Os ydych yn cael anawsterau gyda $BrandShortName, gall ei adnewyddu helpu.\n \nBydd hyn yn adfer y gosodiadau rhagosodedig ac yn tynnu'r ychwanegion. Cychwynnwch o'r newydd ar gyfer y perfformiad gorau posibl.
+UN_REFRESH_LEARN_MORE=&Dysgu rhagor
+UN_REFRESH_BUTTON=&Adnewyddu $BrandShortName
+
+BANNER_CHECK_EXISTING=Gwirio'r gosodiad presennol…
+
+STATUS_INSTALL_APP=Gosod $BrandShortName…
+STATUS_INSTALL_LANG=Gosod Ffeiliau Iaith (${AB_CD})…
+STATUS_UNINSTALL_MAIN=Dadosod $BrandShortName…
+STATUS_CLEANUP=Ychydig o gadw trefn…
+
+UN_SURVEY_CHECKBOX_LABEL=Dweud wrth Mozilla pam eich bod wedi dadosod $BrandShortName
+
+# _DESC strings support approximately 65 characters per line.
+# One line
+OPTIONS_SUMMARY=Dewis y math o osod sydd orau gennych, yna clicio Nesaf.
+# One line
+OPTION_STANDARD_DESC=Bydd $BrandShortName yn cael ei osod gyda'r dewisiadau mwyaf cyffredin.
+OPTION_STANDARD_RADIO=&Safonol
+# Two lines
+OPTION_CUSTOM_DESC=Gallwch ddewis dewisiadau unigol i'w gosod. Ar gyfer defnyddwyr uwch.
+OPTION_CUSTOM_RADIO=&Cyfaddasu
+
+# LOCALIZATION NOTE:
+# The following text replaces the Install button text on the summary page.
+# Verify that the access key for InstallBtn (in override.properties) and
+# UPGRADE_BUTTON is not already used by SUMMARY_TAKE_DEFAULTS.
+UPGRADE_BUTTON=&Diweddaru
diff --git a/l10n-cy/browser/installer/mui.properties b/l10n-cy/browser/installer/mui.properties
new file mode 100644
index 0000000000..3d072b31bd
--- /dev/null
+++ b/l10n-cy/browser/installer/mui.properties
@@ -0,0 +1,61 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# To make the l10n tinderboxen see changes to this file you can change a value
+# name by adding - to the end of the name followed by chars (e.g. Branding-2).
+
+# LOCALIZATION NOTE:
+
+# This file must be saved as UTF8
+
+# Accesskeys are defined by prefixing the letter that is to be used for the
+# accesskey with an ampersand (e.g. &).
+
+# Do not replace $BrandShortName, $BrandFullName, or $BrandFullNameDA with a
+# custom string and always use the same one as used by the en-US files.
+# $BrandFullNameDA allows the string to contain an ampersand (e.g. DA stands
+# for double ampersand) and prevents the letter following the ampersand from
+# being used as an accesskey.
+
+# You can use \n to create a newline in the string but only when the string
+# from en-US contains a \n.
+
+MUI_TEXT_WELCOME_INFO_TITLE=Croeso i Ddewin Gosod $BrandFullNameDA
+MUI_TEXT_WELCOME_INFO_TEXT=Bydd y dewin yn eich tywys wrth osod $BrandFullNameDA.\n\nArgymhellir eich bod yn cau pob rhaglen arall cyn cychwyn gosod. Bydd hyn yn ei gwneud yn bosibl i ddiweddaru'r ffeiliau system berthnasol heb fod angen ailgychwyn eich cyfrifiadur.\n\n$_CLICK
+MUI_TEXT_COMPONENTS_TITLE=Dewis Cydrannau
+MUI_TEXT_COMPONENTS_SUBTITLE=Dewiswch pa nodweddion $BrandFullNameDA rydych am eu gosod.
+MUI_INNERTEXT_COMPONENTS_DESCRIPTION_TITLE=Disgrifiad
+MUI_INNERTEXT_COMPONENTS_DESCRIPTION_INFO=Rhowch eich llygoden ar draws cydran i weld ei ddisgrifiad.
+MUI_TEXT_DIRECTORY_TITLE=Dewis Lleoliad Gosod
+MUI_TEXT_DIRECTORY_SUBTITLE=Dewiswch y ffolder lle mae gosod $BrandFullNameDA.
+MUI_TEXT_INSTALLING_TITLE=Gosod
+MUI_TEXT_INSTALLING_SUBTITLE=Arhoswch tra bod $BrandFullNameDA yn cael ei osod.
+MUI_TEXT_FINISH_TITLE=Gosod wedi ei Gwblhau
+MUI_TEXT_FINISH_SUBTITLE=Gosod wedi ei gwblhau'n llwyddiannus.
+MUI_TEXT_ABORT_TITLE=Atalwyd y Gosod
+MUI_TEXT_ABORT_SUBTITLE=Ni chwblhawyd y gosod yn llwyddiannus.
+MUI_BUTTONTEXT_FINISH=Gor&ffen
+MUI_TEXT_FINISH_INFO_TITLE=Cwblhau Dewin Gosod $BrandFullNameDA
+MUI_TEXT_FINISH_INFO_TEXT=Mae $BrandFullNameDA. wedi'i osod ar eich cyfrifiadur.\n\nCliciwch Gorffen i gau'r dewin.
+MUI_TEXT_FINISH_INFO_REBOOT=Rhaid ailgychwyn eich cyfrifiadur er mwyn cwblhau gosod $BrandFullNameDA. Hoffech chi wneud hynny?
+MUI_TEXT_FINISH_REBOOTNOW=Ail gychwyn nawr
+MUI_TEXT_FINISH_REBOOTLATER=Rwyf am ailgychwyn yn ddiweddarach
+MUI_TEXT_STARTMENU_TITLE=Dewis Ffolder Dewislen Cychwyn
+MUI_TEXT_STARTMENU_SUBTITLE=Dewiswch ffolder Dewislen Cychwyn ar gyfer llwybrau byr $BrandFullNameDA.
+MUI_INNERTEXT_STARTMENU_TOP=Dewiswch ffolder Dewislen Cychwyn lle'r hoffech greu llwybrau byr y rhaglen. Gallwch osod enw i'r ffolder newydd.
+MUI_TEXT_ABORTWARNING=Ydych chi'n siŵr eich bod am adael Gosod $BrandFullName?
+MUI_UNTEXT_WELCOME_INFO_TITLE=Croeso i Ddewin Dadosod $BrandFullNameDA
+MUI_UNTEXT_WELCOME_INFO_TEXT=Bydd y dewin yn eich tywys drwy ddadosod $BrandFullNameDA.\n\nCyn cychwyn dadosod gwnewch yn siŵr nad yw $BrandFullNameDA yn rhedeg.\n\n$_CLICK
+MUI_UNTEXT_CONFIRM_TITLE=Dadosod $BrandFullNameDA
+MUI_UNTEXT_CONFIRM_SUBTITLE=Tynnu $BrandFullNameDA oddi ar eich cyfrifiadur.
+MUI_UNTEXT_UNINSTALLING_TITLE=Dadosod
+MUI_UNTEXT_UNINSTALLING_SUBTITLE=Arhoswch tra bo $BrandFullNameDA yn cael ei dadosod.
+MUI_UNTEXT_FINISH_TITLE=Dadosod wedi ei gwblhau
+MUI_UNTEXT_FINISH_SUBTITLE=Dadosod wedi ei gwblhau'n llwyddiannus.
+MUI_UNTEXT_ABORT_TITLE=Atal y Dadosod
+MUI_UNTEXT_ABORT_SUBTITLE=Ni chwyblhawyd y dadosod yn llwyddiannus.
+MUI_UNTEXT_FINISH_INFO_TITLE=Cwblhau Dewin Dadosod $BrandFullNameDA
+MUI_UNTEXT_FINISH_INFO_TEXT=Mae $BrandFullNameDA wedi ei dadosod o'ch cyfrifiadur.\n\nCliciwch Gorffen i gau'r dewin.
+MUI_UNTEXT_FINISH_INFO_REBOOT=Rhaid ailgychwyn eich cyfrifiadur er mwyn cwblhau dadosod $BrandFullNameDA. Hoffech chi ailgychwyn?
+MUI_UNTEXT_ABORTWARNING=Ydych chi'n siŵr eich bod am adael dadosod $BrandFullName Uninstall?
diff --git a/l10n-cy/browser/installer/nsisstrings.properties b/l10n-cy/browser/installer/nsisstrings.properties
new file mode 100644
index 0000000000..017ead4d64
--- /dev/null
+++ b/l10n-cy/browser/installer/nsisstrings.properties
@@ -0,0 +1,50 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# LOCALIZATION NOTE:
+
+# This file must be saved as UTF8
+
+# Accesskeys are defined by prefixing the letter that is to be used for the
+# accesskey with an ampersand (e.g. &).
+
+# Do not replace $BrandShortName, $BrandProductName, $BrandFullName,
+# or $BrandFullNameDA with a custom string and always use the same one as used
+# by the en-US files.
+# $BrandFullNameDA allows the string to contain an ampersand (e.g. DA stands
+# for double ampersand) and prevents the letter following the ampersand from
+# being used as an accesskey.
+
+# You can use \n to create a newline in the string but only when the string
+# from en-US contains a \n.
+
+INSTALLER_WIN_CAPTION=Gosodwr $BrandShortName
+
+STUB_CLEANUP_PAVEOVER_HEADER2=Mae $BrandShortName eisoes wedi ei osod. Gadewch i ni ei ddiweddaru.
+STUB_CLEANUP_REINSTALL_HEADER2=Mae $BrandShortName wedi ei osod o'r blaen. Beth am i ni osod copi newydd.
+
+STUB_CLEANUP_PAVEOVER_BUTTON2=Diweddaru
+STUB_CLEANUP_REINSTALL_BUTTON2=Ail-osod
+STUB_CLEANUP_CHECKBOX_LABEL2=Adfer y gosodiadau rhagosodedig a thynnu hen ychwanegion ar gyfer y perfformiad gorau
+
+STUB_INSTALLING_LABEL2=Wrthi'n gosod…
+STUB_INSTALLING_HEADLINE2=Optimeiddio'ch gosodiadau ar gyfer cyflymder, preifatrwydd a diogelwch.
+STUB_INSTALLING_BODY2=Bydd $BrandShortName yn barod mewn ychydig eiliadau.
+STUB_BLURB_FIRST1=Y $BrandShortName cyflymaf a mwyaf ymatebol eto
+STUB_BLURB_SECOND1=Llwytho tudalennau a newid tabiau yn gynt
+STUB_BLURB_THIRD1=Pori preifat pwerus
+STUB_BLURB_FOOTER2=Ar gyfer pobl, nid elw
+
+WARN_MIN_SUPPORTED_OSVER_MSG=Ymddiheuriadau, nid oes modd gosod $BrandShortName. Mae'r fersiwn hwn o $BrandShortName angen ${MinSupportedVer} neu fwy diweddar. Cliciwch ar y botwm Iawn am wybodaeth bellach.
+WARN_MIN_SUPPORTED_CPU_MSG=Ymddiheuriadau, nid oes modd gosod $BrandShortName. Mae'r fersiwn hwn o $BrandShortName angen prosesydd gyda chefnogaeth ar gyfer ${MinSupportedCPU}. Cliciwch ar y botwm Iawn am wybodaeth bellach.
+WARN_MIN_SUPPORTED_OSVER_CPU_MSG=Ymddiheuriadau, nid oes modd gosod $BrandShortName. Mae'r fersiwn hwn o $BrandShortName angen ${MinSupportedVer} a phrosesydd gyda chefnogaeth ar gyfer ${MinSupportedCPU}. Cliciwch ar y botwm Iawn am wybodaeth bellach.
+WARN_WRITE_ACCESS_QUIT=Nid oes gennych fynediad i ysgrifennu i'r cyfeiriadur gosod
+WARN_DISK_SPACE_QUIT=Nid oes gennych ddigon o le ar ddisg i'w osod.
+
+ERROR_DOWNLOAD_CONT=Hmm. Am rhyw reswm, nid oedd modd i ni osod $BrandShortName.\nCliciwch Iawn i gychwyn eto.
+
+STUB_CANCEL_PROMPT_HEADING=Ydych chi am osod $BrandShortName?
+STUB_CANCEL_PROMPT_MESSAGE=Os fyddwch yn diddymu, ni fydd $BrandShortName yn cael ei osod.
+STUB_CANCEL_PROMPT_BUTTON_CONTINUE=Gosod $BrandShortName
+STUB_CANCEL_PROMPT_BUTTON_EXIT=Diddymu
diff --git a/l10n-cy/browser/installer/override.properties b/l10n-cy/browser/installer/override.properties
new file mode 100644
index 0000000000..fdd29800a7
--- /dev/null
+++ b/l10n-cy/browser/installer/override.properties
@@ -0,0 +1,86 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# LOCALIZATION NOTE:
+
+# This file must be saved as UTF8
+
+# Accesskeys are defined by prefixing the letter that is to be used for the
+# accesskey with an ampersand (e.g. &).
+
+# Do not replace $BrandShortName, $BrandFullName, or $BrandFullNameDA with a
+# custom string and always use the same one as used by the en-US files.
+# $BrandFullNameDA allows the string to contain an ampersand (e.g. DA stands
+# for double ampersand) and prevents the letter following the ampersand from
+# being used as an accesskey.
+
+# You can use \n to create a newline in the string but only when the string
+# from en-US contains a \n.
+
+# Strings that require a space at the end should be enclosed with double
+# quotes and the double quotes will be removed. To add quotes to the beginning
+# and end of a strong enclose the add and additional double quote to the
+# beginning and end of the string (e.g. ""This will include quotes"").
+
+SetupCaption=Gosod $BrandFullName
+UninstallCaption=Dadosod $BrandFullName
+BackBtn=< &Nôl
+NextBtn=N&esaf >
+AcceptBtn=Rwy'n &derbyn amodau'r Cytundeb Trwyddedu
+DontAcceptBtn=&Nid wyf yn derbyn amodau'r Cytundeb Trwyddedu
+InstallBtn=&Gosod
+UninstallBtn=&Dadosod
+CancelBtn=Diddymu
+CloseBtn=&Cau
+BrowseBtn=&Pori…
+ShowDetailsBtn=&Dangos manylion
+ClickNext=Clicio Nesaf i barhau.
+ClickInstall=Clicio Gosod i gychwyn gosod.
+ClickUninstall=Cliciwch Dadosod i gychwyn dadosod.
+Completed=Cwblhawyd
+LicenseTextRB=Darllenwch y cytundeb trwyddedu cyn gosod $BrandFullNameDA. Os ydych yn derbyn amodau’r cytundeb, dewiswch y dewis cyntaf isod. $_CLICK
+ComponentsText=Ticiwch y cydrannau rydych am eu gosod a dad dicio'r cydrannau nad ydych am eu gosod. $_CLICK
+ComponentsSubText2_NoInstTypes=Dewiswch gydrannau i'w gosod:
+DirText=Bydd y gosod yn gosod $BrandFullNameDA yn y ffolder canlynol. I'w osod mewn ffolder gwahanol, cliciwch Pori a dewis ffolder arall. $_CLICK
+DirSubText=Ffolder Cyrchfan
+DirBrowseText=Dewiswch y ffolder i osod $BrandFullNameDA ynddi:
+SpaceAvailable="Lle ar gael: "
+SpaceRequired="Lle angenrheidiol: "
+UninstallingText=Bydd $BrandFullNameDA yn cael ei ddadosod o'r ffolder canlynol. $_CLICK
+UninstallingSubText=Dadosod o:
+FileError=Gwall wrth agor ffeil i'w ysgrifennu: \r\n\r\n$0\r\n\r\nCiciwch Atal i atal y gosod,\r\nAil-geisio i geisio eto neu\r\nAnwybyddu i hepgor y ffeil.
+FileError_NoIgnore=Gwall wrth agor ffeil i'w ysgrifennu: \r\n\r\n$0\r\n\r\nAil-geisio i geisio eto neu\r\nDiddymu i atal y gosod.
+CantWrite="Methu ysgrifennu: "
+CopyFailed=Methodd copïo
+CopyTo="Copïo i "
+Registering="Cofrestru: "
+Unregistering="Dadgofrestru: "
+SymbolNotFound="Methu canfod symbol: "
+CouldNotLoad="Methu llwytho: "
+CreateFolder="Creu ffolder: "
+CreateShortcut="Creu llwybr byr: "
+CreatedUninstaller="Creu dadosodwr: "
+Delete="Dileu ffeil: "
+DeleteOnReboot="Dileu wrth ailgychwyn: "
+ErrorCreatingShortcut="Gwall wrth greu llwybr byr: "
+ErrorCreating="Creu gwall: "
+ErrorDecompressing=Gwall wrth ddatgywasgu data! Gosodwr llwgr?
+ErrorRegistering=Gwall cofrestru DLL
+ExecShell="ExecShell: "
+Exec="Gweithredu: "
+Extract="Echdynnu: "
+ErrorWriting="Echdynnu: gwall ysgrifennu i ffeil "
+InvalidOpcode=Gosodwr gwallus: opcode annilys
+NoOLE="Dim OLE ar gyfer: "
+OutputFolder="Ffolder allbwn: "
+RemoveFolder="Tynnu ffolder: "
+RenameOnReboot="Ailenwi wrth ailgychwyn: "
+Rename="Ailenwi: "
+Skipped="Hepgorwyd: "
+CopyDetails=Copïo Manylion i'r Clipfwrdd
+LogInstall=Cofnodi'r broses gosod
+Byte=B
+Kilo=K
+Mega=M
+Giga=G
diff --git a/l10n-cy/browser/langpack-metadata.ftl b/l10n-cy/browser/langpack-metadata.ftl
new file mode 100644
index 0000000000..c122b87c1a
--- /dev/null
+++ b/l10n-cy/browser/langpack-metadata.ftl
@@ -0,0 +1,12 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+## Strings used to define the metadata of langpacks published on addons.mozilla.org.
+## Only text elements and literals are supported for these strings.
+
+langpack-creator = mozilla.org
+# To credit multiple contributors, use a comma-delimited list.
+# Example: Joe Solon, Suzy Solon
+langpack-contributors = Rhoslyn Prys, David Chan, Dewi B. Jones
diff --git a/l10n-cy/browser/pdfviewer/chrome.properties b/l10n-cy/browser/pdfviewer/chrome.properties
new file mode 100644
index 0000000000..88f879fe7d
--- /dev/null
+++ b/l10n-cy/browser/pdfviewer/chrome.properties
@@ -0,0 +1,20 @@
+# Copyright 2012 Mozilla Foundation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Chrome notification bar messages and buttons
+unsupported_feature=Efallai na fydd y ddogfen PDF yn cael ei dangos yn gywir.
+unsupported_feature_forms=Mae'r ffurflen PDF hon yn cynnwys ffurflenni. Nid yw llanw ffurflenni'n cael ei gynnal.
+unsupported_feature_signatures=Mae'r ddogfen PDF hon yn cynnwys llofnodion digidol. Nid yw gwirio llofnodion yn cael ei gynnal.
+open_with_different_viewer=Agor gyda Darllenydd Gwahanol
+open_with_different_viewer.accessKey=o
diff --git a/l10n-cy/browser/pdfviewer/viewer.properties b/l10n-cy/browser/pdfviewer/viewer.properties
new file mode 100644
index 0000000000..d66930db3c
--- /dev/null
+++ b/l10n-cy/browser/pdfviewer/viewer.properties
@@ -0,0 +1,277 @@
+# Copyright 2012 Mozilla Foundation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Main toolbar buttons (tooltips and alt text for images)
+previous.title=Tudalen Flaenorol
+previous_label=Blaenorol
+next.title=Tudalen Nesaf
+next_label=Nesaf
+
+# LOCALIZATION NOTE (page.title): The tooltip for the pageNumber input.
+page.title=Tudalen
+# LOCALIZATION NOTE (of_pages): "{{pagesCount}}" will be replaced by a number
+# representing the total number of pages in the document.
+of_pages=o {{pagesCount}}
+# LOCALIZATION NOTE (page_of_pages): "{{pageNumber}}" and "{{pagesCount}}"
+# will be replaced by a number representing the currently visible page,
+# respectively a number representing the total number of pages in the document.
+page_of_pages=({{pageNumber}} o {{pagesCount}})
+
+zoom_out.title=Chwyddo Allan
+zoom_out_label=Chwyddo Allan
+zoom_in.title=Chwyddo Mewn
+zoom_in_label=Chwyddo Mewn
+zoom.title=Chwyddo
+presentation_mode.title=Newid i'r Modd Cyflwyno
+presentation_mode_label=Modd Cyflwyno
+open_file.title=Agor Ffeil
+open_file_label=Agor
+print.title=Argraffu
+print_label=Argraffu
+download.title=Llwyth
+download_label=Llwytho i Lawr
+save.title=Cadw
+save_label=Cadw
+bookmark.title=Golwg cyfredol (copïo neu agor ffenestr newydd)
+bookmark_label=Golwg Gyfredol
+
+bookmark1.title=Tudalen Gyfredol (Gweld URL o'r Dudalen Gyfredol)
+bookmark1_label=Tudalen Gyfredol
+
+# Secondary toolbar and context menu
+tools.title=Offer
+tools_label=Offer
+first_page.title=Mynd i'r Dudalen Gyntaf
+first_page_label=Mynd i'r Dudalen Gyntaf
+last_page.title=Mynd i'r Dudalen Olaf
+last_page_label=Mynd i'r Dudalen Olaf
+page_rotate_cw.title=Cylchdroi Clocwedd
+page_rotate_cw_label=Cylchdroi Clocwedd
+page_rotate_ccw.title=Cylchdroi Gwrthglocwedd
+page_rotate_ccw_label=Cylchdroi Gwrthglocwedd
+
+cursor_text_select_tool.title=Galluogi Dewis Offeryn Testun
+cursor_text_select_tool_label=Offeryn Dewis Testun
+cursor_hand_tool.title=Galluogi Offeryn Llaw
+cursor_hand_tool_label=Offeryn Llaw
+
+scroll_page.title=Defnyddio Sgrolio Tudalen
+scroll_page_label=Sgrolio Tudalen
+scroll_vertical.title=Defnyddio Sgrolio Fertigol
+scroll_vertical_label=Sgrolio Fertigol
+scroll_horizontal.title=Defnyddio Sgrolio Llorweddol
+scroll_horizontal_label=Sgrolio Llorweddol
+scroll_wrapped.title=Defnyddio Sgrolio Amlapio
+scroll_wrapped_label=Sgrolio Amlapio
+
+spread_none.title=Peidio uno trawsdaleniadau
+spread_none_label=Dim Trawsdaleniadau
+spread_odd.title=Uno trawsdaleniadau gan gychwyn gyda thudalennau odrif
+spread_odd_label=Trawsdaleniadau Odrif
+spread_even.title=Uno trawsdaleniadau gan gychwyn gyda thudalennau eilrif
+spread_even_label=Trawsdaleniadau Eilrif
+
+# Document properties dialog box
+document_properties.title=Priodweddau Dogfen…
+document_properties_label=Priodweddau Dogfen…
+document_properties_file_name=Enw ffeil:
+document_properties_file_size=Maint ffeil:
+# LOCALIZATION NOTE (document_properties_kb): "{{size_kb}}" and "{{size_b}}"
+# will be replaced by the PDF file size in kilobytes, respectively in bytes.
+document_properties_kb={{size_kb}} KB ({{size_b}} beit)
+# LOCALIZATION NOTE (document_properties_mb): "{{size_mb}}" and "{{size_b}}"
+# will be replaced by the PDF file size in megabytes, respectively in bytes.
+document_properties_mb={{size_mb}} MB ({{size_b}} beit)
+document_properties_title=Teitl:
+document_properties_author=Awdur:
+document_properties_subject=Pwnc:
+document_properties_keywords=Allweddair:
+document_properties_creation_date=Dyddiad Creu:
+document_properties_modification_date=Dyddiad Addasu:
+# LOCALIZATION NOTE (document_properties_date_string): "{{date}}" and "{{time}}"
+# will be replaced by the creation/modification date, and time, of the PDF file.
+document_properties_date_string={{date}}, {{time}}
+document_properties_creator=Crewr:
+document_properties_producer=Cynhyrchydd PDF:
+document_properties_version=Fersiwn PDF:
+document_properties_page_count=Cyfrif Tudalen:
+document_properties_page_size=Maint Tudalen:
+document_properties_page_size_unit_inches=o fewn
+document_properties_page_size_unit_millimeters=mm
+document_properties_page_size_orientation_portrait=portread
+document_properties_page_size_orientation_landscape=tirlun
+document_properties_page_size_name_a3=A3
+document_properties_page_size_name_a4=A4
+document_properties_page_size_name_letter=Llythyr
+document_properties_page_size_name_legal=Cyfreithiol
+# LOCALIZATION NOTE (document_properties_page_size_dimension_string):
+# "{{width}}", "{{height}}", {{unit}}, and {{orientation}} will be replaced by
+# the size, respectively their unit of measurement and orientation, of the (current) page.
+document_properties_page_size_dimension_string={{width}} × {{height}} {{unit}} ({{orientation}})
+# LOCALIZATION NOTE (document_properties_page_size_dimension_name_string):
+# "{{width}}", "{{height}}", {{unit}}, {{name}}, and {{orientation}} will be replaced by
+# the size, respectively their unit of measurement, name, and orientation, of the (current) page.
+document_properties_page_size_dimension_name_string={{width}} × {{height}} {{unit}} ({{name}}, {{orientation}})
+# LOCALIZATION NOTE (document_properties_linearized): The linearization status of
+# the document; usually called "Fast Web View" in English locales of Adobe software.
+document_properties_linearized=Golwg Gwe Cyflym:
+document_properties_linearized_yes=Iawn
+document_properties_linearized_no=Na
+document_properties_close=Cau
+
+print_progress_message=Paratoi dogfen ar gyfer ei hargraffu…
+# LOCALIZATION NOTE (print_progress_percent): "{{progress}}" will be replaced by
+# a numerical per cent value.
+print_progress_percent={{progress}}%
+print_progress_close=Diddymu
+
+# Tooltips and alt text for side panel toolbar buttons
+# (the _label strings are alt text for the buttons, the .title strings are
+# tooltips)
+toggle_sidebar.title=Toglo'r Bar Ochr
+toggle_sidebar_notification2.title=Toglo'r Bar Ochr (mae'r ddogfen yn cynnwys amlinelliadau/atodiadau/haenau)
+toggle_sidebar_label=Toglo'r Bar Ochr
+document_outline.title=Dangos Amlinell Dogfen (clic dwbl i ymestyn/cau pob eitem)
+document_outline_label=Amlinelliad Dogfen
+attachments.title=Dangos Atodiadau
+attachments_label=Atodiadau
+layers.title=Dangos Haenau (cliciwch ddwywaith i ailosod yr holl haenau i'r cyflwr rhagosodedig)
+layers_label=Haenau
+thumbs.title=Dangos Lluniau Bach
+thumbs_label=Lluniau Bach
+current_outline_item.title=Canfod yr Eitem Amlinellol Gyfredol
+current_outline_item_label=Yr Eitem Amlinellol Gyfredol
+findbar.title=Canfod yn y Ddogfen
+findbar_label=Canfod
+
+additional_layers=Haenau Ychwanegol
+# LOCALIZATION NOTE (page_landmark): "{{page}}" will be replaced by the page number.
+page_landmark=Tudalen {{page}}
+# Thumbnails panel item (tooltip and alt text for images)
+# LOCALIZATION NOTE (thumb_page_title): "{{page}}" will be replaced by the page
+# number.
+thumb_page_title=Tudalen {{page}}
+# LOCALIZATION NOTE (thumb_page_canvas): "{{page}}" will be replaced by the page
+# number.
+thumb_page_canvas=Llun Bach Tudalen {{page}}
+
+# Find panel button title and messages
+find_input.title=Canfod
+find_input.placeholder=Canfod yn y ddogfen…
+find_previous.title=Canfod enghraifft flaenorol o'r ymadrodd
+find_previous_label=Blaenorol
+find_next.title=Canfod enghraifft nesaf yr ymadrodd
+find_next_label=Nesaf
+find_highlight=Amlygu popeth
+find_match_case_label=Cydweddu maint
+find_match_diacritics_label=Diacritigau Cyfatebol
+find_entire_word_label=Geiriau cyfan
+find_reached_top=Wedi cyrraedd brig y dudalen, parhau o'r gwaelod
+find_reached_bottom=Wedi cyrraedd diwedd y dudalen, parhau o'r brig
+# LOCALIZATION NOTE (find_match_count): The supported plural forms are
+# [one|two|few|many|other], with [other] as the default value.
+# "{{current}}" and "{{total}}" will be replaced by a number representing the
+# index of the currently active find result, respectively a number representing
+# the total number of matches in the document.
+find_match_count={[ plural(total) ]}
+find_match_count[one]={{current}} o {{total}} cydweddiad
+find_match_count[two]={{current}} o {{total}} cydweddiad
+find_match_count[few]={{current}} o {{total}} cydweddiad
+find_match_count[many]={{current}} o {{total}} cydweddiad
+find_match_count[other]={{current}} o {{total}} cydweddiad
+# LOCALIZATION NOTE (find_match_count_limit): The supported plural forms are
+# [zero|one|two|few|many|other], with [other] as the default value.
+# "{{limit}}" will be replaced by a numerical value.
+find_match_count_limit={[ plural(limit) ]}
+find_match_count_limit[zero]=Mwy na {{limit}} cydweddiad
+find_match_count_limit[one]=Mwy na {{limit}} cydweddiad
+find_match_count_limit[two]=Mwy na {{limit}} cydweddiad
+find_match_count_limit[few]=Mwy na {{limit}} cydweddiad
+find_match_count_limit[many]=Mwy na {{limit}} cydweddiad
+find_match_count_limit[other]=Mwy na {{limit}} cydweddiad
+find_not_found=Heb ganfod ymadrodd
+
+# Error panel labels
+error_more_info=Rhagor o Wybodaeth
+error_less_info=Llai o wybodaeth
+error_close=Cau
+# LOCALIZATION NOTE (error_version_info): "{{version}}" and "{{build}}" will be
+# replaced by the PDF.JS version and build ID.
+error_version_info=PDF.js v{{version}} (build: {{build}})
+# LOCALIZATION NOTE (error_message): "{{message}}" will be replaced by an
+# english string describing the error.
+error_message=Neges: {{message}}
+# LOCALIZATION NOTE (error_stack): "{{stack}}" will be replaced with a stack
+# trace.
+error_stack=Stac: {{stack}}
+# LOCALIZATION NOTE (error_file): "{{file}}" will be replaced with a filename
+error_file=Ffeil: {{file}}
+# LOCALIZATION NOTE (error_line): "{{line}}" will be replaced with a line number
+error_line=Llinell: {{line}}
+
+# Predefined zoom values
+page_scale_width=Lled Tudalen
+page_scale_fit=Ffit Tudalen
+page_scale_auto=Chwyddo Awtomatig
+page_scale_actual=Maint Gwirioneddol
+# LOCALIZATION NOTE (page_scale_percent): "{{scale}}" will be replaced by a
+# numerical scale value.
+page_scale_percent={{scale}}%
+
+# Loading indicator messages
+loading=Yn llwytho…
+loading_error=Digwyddodd gwall wrth lwytho'r PDF.
+invalid_file_error=Ffeil PDF annilys neu llwgr.
+missing_file_error=Ffeil PDF coll.
+unexpected_response_error=Ymateb annisgwyl gan y gweinydd.
+
+rendering_error=Digwyddodd gwall wrth adeiladu'r dudalen.
+
+# LOCALIZATION NOTE (annotation_date_string): "{{date}}" and "{{time}}" will be
+# replaced by the modification date, and time, of the annotation.
+annotation_date_string={{date}}, {{time}}
+
+# LOCALIZATION NOTE (text_annotation_type.alt): This is used as a tooltip.
+# "{{type}}" will be replaced with an annotation type from a list defined in
+# the PDF spec (32000-1:2008 Table 169 – Annotation types).
+# Some common types are e.g.: "Check", "Text", "Comment", "Note"
+text_annotation_type.alt=[Anodiad {{type}} ]
+password_label=Rhowch gyfrinair i agor y PDF.
+password_invalid=Cyfrinair annilys. Ceisiwch eto.
+password_ok=Iawn
+password_cancel=Diddymu
+
+printing_not_supported=Rhybudd: Nid yw argraffu yn cael ei gynnal yn llawn gan y porwr.
+printing_not_ready=Rhybudd: Nid yw'r PDF wedi ei lwytho'n llawn ar gyfer argraffu.
+web_fonts_disabled=Ffontiau gwe wedi eu hanalluogi: methu defnyddio ffontiau PDF mewnblanedig.
+
+# Editor
+editor_free_text2.title=Testun
+editor_free_text2_label=Testun
+editor_ink2.title=Lluniadu
+editor_ink2_label=Lluniadu
+
+free_text2_default_content=Cychwyn teipio…
+
+# Editor Parameters
+editor_free_text_color=Lliw
+editor_free_text_size=Maint
+editor_ink_color=Lliw
+editor_ink_thickness=Trwch
+editor_ink_opacity=Didreiddedd
+
+# Editor aria
+editor_free_text2_aria_label=Golygydd Testun
+editor_ink2_aria_label=Golygydd Lluniadu
+editor_ink_canvas_aria_label=Delwedd wedi'i chreu gan ddefnyddwyr
diff --git a/l10n-cy/browser/updater/updater.ini b/l10n-cy/browser/updater/updater.ini
new file mode 100644
index 0000000000..9944ebe4f7
--- /dev/null
+++ b/l10n-cy/browser/updater/updater.ini
@@ -0,0 +1,9 @@
+; This Source Code Form is subject to the terms of the Mozilla Public
+; License, v. 2.0. If a copy of the MPL was not distributed with this
+; file, You can obtain one at http://mozilla.org/MPL/2.0/.
+; This file is in the UTF-8 encoding
+; All strings must be less than 600 chars.
+[Strings]
+TitleText=Diweddaru %MOZ_APP_DISPLAYNAME%
+InfoText=Mae %MOZ_APP_DISPLAYNAME% yn gosod eich diweddariadau a bydd yn cychwyn ymhen ychydig…
+MozillaMaintenanceDescription=Mae'r Mozilla Maintenance Service yn sicrhau fod gennych y fersiwn mwyaf diweddar a diogel o Mozilla Firefox ar eich cyfrifiadur. Mae cadw Firefox yn gyfredol yn bwysig iawn ar gyfer eich diogelwch ar-lein, ac mae Mozilla yn eich annog yn gryf i gadw'r gwasanaeth yma wedi ei alluogi.