# Flags ## --allow-hosts ALLOW_HOSTS... Values of the `Host` header to allow for incoming requests. By default the value of HOST is allowed. If `--allow-hosts` is provided, exactly the given values will be permitted. For example `--allow-host geckodriver.test webdriver.local` will allow requests with `Host` set to `geckodriver.test` or `webdriver.local`. Requests with `Host` set to an IP address are always allowed. ## --allow-origins ALLOW_ORIGINS... Values of the `Origin` header to allow for incoming requests. `Origin` is set by web browsers for all `POST` requests, and most other cross-origin requests. By default any request with an `Origin` header is rejected to protect against malicious websites trying to access geckodriver running on the local machine. If `--allow-origins` is provided, web services running on the given origin will be able to make requests to geckodriver. For example `--allow-origins https://webdriver.test:8080` will allow a web-based service on the origin with scheme `https`, hostname `webdriver.test`, and port `8080` to access the geckodriver instance. ## --android-storage ANDROID_STORAGE **Deprecation warning**: This argument is deprecated and planned to be removed with the 0.31.0 release of geckodriver. As such it shouldn't be used with version 0.30.0 or later anymore. By default the automatic detection will now use the external storage location, which is always readable and writeable. Selects the test data location on the Android device, eg. the Firefox profile. By default `auto` is used.

Value	Description
auto	Best suitable location based on whether the device is rooted. If the device is rooted `internal` is used, otherwise `app`.
app	Location: `/data/data/%androidPackage%/test_root` Based on the `androidPackage` capability that is passed as part of `moz:firefoxOptions` when creating a new session. Commands that change data in the app's directory are executed using run-as. This requires that the installed app is debuggable.
internal	Location: `/data/local/tmp/test_root` The device must be rooted since when the app runs, files that are created in the profile, which is owned by the app user, cannot be changed by the shell user. Commands will be executed via `su`.
sdcard	Location: `$EXTERNAL_STORAGE/Android/data/%androidPackage%/files/test_root` This location is supported by all versions of Android whether if the device is rooted or not.

## -b BINARY / --binary BINARY Path to the Firefox binary to use. By default geckodriver tries to find and use the system installation of Firefox, but that behaviour can be changed by using this option. Note that the `binary` capability of the `moz:firefoxOptions` object that is passed when [creating a new session] will override this option. On Linux systems it will use the first _firefox_ binary found by searching the `PATH` environmental variable, which is roughly equivalent to calling [whereis(1)] and extracting the second column: ```shell % whereis firefox firefox: /usr/bin/firefox /usr/local/firefox ``` On macOS, the binary is found by looking for the first _firefox-bin_ binary in the same fashion as on Linux systems. This means it is possible to also use `PATH` to control where geckodriver should find Firefox on macOS. It will then look for _/Applications/Firefox.app_. On Windows systems, geckodriver looks for the system Firefox by scanning the Windows registry. [creating a new session]: https://w3c.github.io/webdriver/#new-session [whereis(1)]: http://www.manpagez.com/man/1/whereis/ ## --connect-existing Connect geckodriver to an existing Firefox instance. This means geckodriver will abstain from the default of starting a new Firefox session. The existing Firefox instance must have [Marionette] enabled. To enable the remote protocol in Firefox, you can pass the `-marionette` flag. Unless the `marionette.port` preference has been user-set, Marionette will listen on port 2828. So when using `--connect-existing` it is likely you will also have to use `--marionette-port` to set the correct port. `--marionette-port`: #marionette-port ## --host HOST Host to use for the WebDriver server. Defaults to 127.0.0.1. ## --jsdebugger Attach [browser toolbox] debugger when Firefox starts. This is useful for debugging [Marionette] internals. To be prompted at the start of the test run or between tests, you can set the `marionette.debugging.clicktostart` preference to `true`. For reference, below is the list of preferences that enables the chrome debugger. These are all set implicitly when the argument is passed to geckodriver. * `devtools.browsertoolbox.panel` -> `jsdebugger` Selects the Debugger panel by default. * `devtools.chrome.enabled` → true Enables debugging of chrome code. * `devtools.debugger.prompt-connection` → false Controls the remote connection prompt. Note that this will automatically expose your Firefox instance to localhost. * `devtools.debugger.remote-enabled` → true Allows a remote debugger to connect, which is necessary for debugging chrome code. [browser toolbox]: https://developer.mozilla.org/en-US/docs/Tools/Browser_Toolbox ## --log LEVEL Set the Gecko and geckodriver log level. Possible values are `fatal`, `error`, `warn`, `info`, `config`, `debug`, and `trace`. ## --log-no-truncate Disables truncation of long log lines. ## --marionette-host HOST Selects the host for geckodriver’s connection to the [Marionette] remote protocol. Defaults to 127.0.0.1. ## --marionette-port PORT Selects the port for geckodriver’s connection to the [Marionette] remote protocol. In the default mode where geckodriver starts and manages the Firefox process, it will pick a free port assigned by the system and set the `marionette.port` preference in the profile. When `--connect-existing` is used and the Firefox process is not under geckodriver’s control, it will simply connect to PORT. `--connect-existing`: #connect-existing ## -p PORT / --port PORT Port to use for the WebDriver server. Defaults to 4444. A helpful trick is that it is possible to bind to 0 to get the system to atomically assign a free port. ## --profile-root PROFILE_ROOT Path to the directory to use when creating temporary profiles. By default this is the system temporary directory. Both geckodriver and Firefox must have read-write access to this path. This setting can be useful when Firefox is sandboxed from the host filesystem such that it doesn't share the same system temporary directory as geckodriver (e.g. when running Firefox inside a container or packaged as a snap). ## -v[v] Increases the logging verbosity by to debug level when passing a single `-v`, or to trace level if `-vv` is passed. This is analogous to passing `--log debug` and `--log trace`, respectively. ## --websocket-portPORT Port to use to connect to WebDriver BiDi. Defaults to 9222. A helpful trick is that it is possible to bind to 0 to get the system to atomically assign a free port. [Marionette]: /testing/marionette/index.rst