<!doctype html> <title>The hidden attribute</title> <link rel=match href=hidden-1-ref.html> <link rel=author title=Ms2ger href=mailto:Ms2ger@gmail.com> <link rel=help href=https://html.spec.whatwg.org/multipage/#the-hidden-attribute> <link rel=help href=https://html.spec.whatwg.org/multipage/#hidden-elements> <p hidden>This line should be visible. <p>This line should not be visible. <script> document.getElementsByTagName("p")[0].hidden = false; document.getElementsByTagName("p")[1].hidden = true; </script>