Not yet stable

For a given set of browsers, what APIs are not yet in all of them.

Example Comparisons
Browsers
Features

Summary

A count of the number of APIs are in Browser X but not in Browser Y.
Not in FirefoxNot in Safari
In Firefox 27
In Safari 38

Unstable APIs

Below is a list of features that are not in all of Firefox and Safari

Raw Data

Quick Links:

HTML Data

API First Browser Date Days in Limbo Notes
html.elements.a.attributionsourceid 📋Safari4/26/20211924
html.elements.a.coords 📋Safari6/23/20038441
Firefox: You can no longer nest an <a> element inside a <map> element to create a hotspot region - coords and shape attribute support removed.Firefox for Android: You can no longer nest an <a> element inside a <map> element to create a hotspot region - coords and shape attribute support removed.
html.elements.a.href.href_sms Firefox4/24/20125213
html.elements.a.shape 📋Safari6/23/20038441
Firefox: You can no longer nest an <a> element inside a <map> element to create a hotspot region - coords and shape attribute support removed.Firefox for Android: You can no longer nest an <a> element inside a <map> element to create a hotspot region - coords and shape attribute support removed.
html.elements.audio.disableremoteplayback 📋Safari3/24/20202322
html.elements.canvas.moz-opaque Firefox6/30/20096242
html.elements.col.char 📋Safari10/26/20076855
html.elements.col.charoff 📋Safari10/26/20076855
html.elements.colgroup.char 📋Safari10/26/20076855
html.elements.colgroup.charoff 📋Safari10/26/20076855
html.elements.form.autocomplete.new-password Firefox5/21/20192630
html.elements.iframe.allow.autoplay 📋Firefox3/10/20202336
html.elements.iframe.allow.document-domain 📋Firefox3/10/20202336
html.elements.iframe.allow.encrypted-media 📋Firefox3/10/20202336
html.elements.iframe.allow.fullscreen 📋Firefox8/25/20202168
html.elements.iframe.allow.gamepad 📋Firefox8/10/20211818
Firefox: The default allowlist is * instead of self (as required by the specification).Firefox for Android: The default allowlist is * instead of self (as required by the specification).
html.elements.iframe.allow.geolocation 📋Firefox3/10/20202336
html.elements.iframe.allow.midi 📋Firefox3/10/20202336
html.elements.iframe.allow.payment 📋Firefox3/10/20202336
html.elements.iframe.allow.publickey-credentials-create 📋Firefox2/20/2024894
html.elements.iframe.allow.publickey-credentials-get 📋Firefox9/26/20231041
html.elements.iframe.allow.speaker-selection 📋Firefox8/1/20231097
Firefox for Android: Not available due to a limitation in Android (see bug 1473346).
html.elements.iframe.allow.web-share 📋Firefox9/22/20202140
Firefox: Firefox recognizes the web-share permissions policy, but this has no effect in versions of Firefox that do not support the share() method.Firefox for Android: Firefox for Android recognizes the web-share permissions policy, but this has no effect in versions of Firefox for Android that do not support the share() method.
html.elements.iframe.sandbox.allow-orientation-lock 📋Firefox9/20/20163603
html.elements.iframe.sandbox.allow-presentation 📋Firefox11/15/20163547
html.elements.input.type_password.insecure_login_handling Firefox3/7/20173435
html.elements.link.blocking 📋Safari12/11/2024599
html.elements.link.rel.alternate_stylesheet 📋Firefox6/17/20086620
html.elements.link.rel.manifest 📋Safari9/18/20231049
html.elements.link.rel.preload.as-track Safari4/12/20183034
html.elements.meta.name.theme-color 📋Safari9/20/20211777
Chrome: Chrome uses the color only on installed progressive web apps.Chrome: Chrome reports support, but does not actually use the color anywhere.Chrome Android: Chrome for Android does not use the color on devices with native dark mode enabled unless it's an installed progressive web app or a trusted web activity.Edge: Edge uses the color only on installed progressive web apps.Quest Browser: Chrome for Android does not use the color on devices with native dark mode enabled unless it's an installed progressive web app or a trusted web activity.
html.elements.script.blocking 📋Safari12/11/2024599
html.elements.script.type.importmap.integrity 📋Safari9/16/2024685
html.elements.style.blocking 📋Safari12/11/2024599
html.elements.summary.display_list_item Firefox9/20/20163603
html.elements.tbody.char Safari6/8/20096264
html.elements.td.char Safari6/8/20096264
html.elements.td.rowspan.rowspan_zero Firefox8/8/20173281
html.elements.template.shadowrootclonable 📋Firefox4/16/2024838
html.elements.template.shadowrootdelegatesfocus 📋Firefox2/20/2024894
html.elements.textarea.autocomplete.new-password Firefox5/21/20192630
html.elements.tfoot.char Safari6/8/20096264
html.elements.th.char Safari6/8/20096264
html.elements.th.rowspan.rowspan_zero Firefox8/8/20173281
html.elements.thead.char Safari6/8/20096264
html.elements.tr.char Safari6/8/20096264
html.elements.tr.charoff Safari6/8/20096264
html.elements.video.disableremoteplayback 📋Safari3/24/20202322
html.elements.video.playsinline 📋Safari9/20/20163603
html.global_attributes.autocapitalize 📋Firefox3/14/20231237
html.global_attributes.autocorrect 📋Safari4/26/20211924
Safari: Takes values of true/false (instead of on/off).Safari: Allowed on <input type='password'> elements.Safari on iOS: Takes values of true/false (instead of on/off).Safari on iOS: Allowed on <input type='password'> elements.
html.global_attributes.contenteditable.plaintext-only Safari3/24/20202322
html.global_attributes.is 📋Firefox10/23/20182840
html.global_attributes.writingsuggestions 📋Safari9/16/2024685
html.manifest.display 📋Safari9/18/20231049
Chrome: display and/or display_override are required for a web app to be installable.Chrome Android: display and/or display_override are required for a web app to be installable.Edge: display and/or display_override are required for a web app to be installable.Quest Browser: display and/or display_override are required for a web app to be installable.Opera: display and/or display_override are required for a web app to be installable.Opera Android: display and/or display_override are required for a web app to be installable.Samsung Internet: display and/or display_override are required for a web app to be installable.WebView Android: display and/or display_override are required for a web app to be installable.
html.manifest.display.browser 📋Safari9/18/20231049
html.manifest.display.standalone 📋Safari9/18/20231049
html.manifest.icons 📋Safari9/18/20231049
Chrome: icons is required for a web app to be installable.Chrome Android: icons is required for a web app to be installable.Edge: icons is required for a web app to be installable.Quest Browser: icons is required for a web app to be installable.Opera: icons is required for a web app to be installable.Opera Android: icons is required for a web app to be installable.Safari: Only used when no apple-touch-icon is present and either "purpose" is set to "any" or "purpose" is not specified.Safari on iOS: Only used when no apple-touch-icon is present and either "purpose" is set to "any" or "purpose" is not specified.Samsung Internet: icons is required for a web app to be installable.WebView Android: icons is required for a web app to be installable.WebView on iOS: Only used when no apple-touch-icon is present and either "purpose" is set to "any" or "purpose" is not specified.
html.manifest.id 📋Safari9/18/20231049
Firefox: The property parses, but has no effect.
html.manifest.name 📋Safari9/18/20231049
Chrome: name or short_name is required for a web app to be installable.Chrome Android: name or short_name is required for a web app to be installable.Edge: name or short_name is required for a web app to be installable.Quest Browser: name or short_name is required for a web app to be installable.Opera: name or short_name is required for a web app to be installable.Opera Android: name or short_name is required for a web app to be installable.Samsung Internet: name or short_name is required for a web app to be installable.WebView Android: name or short_name is required for a web app to be installable.
html.manifest.scope 📋Safari9/18/20231049
html.manifest.short_name 📋Safari9/18/20231049
Chrome: short_name or name is required for a web app to be installable.Chrome Android: short_name or name is required for a web app to be installable.Edge: short_name or name is required for a web app to be installable.Quest Browser: short_name or name is required for a web app to be installable.Opera: short_name or name is required for a web app to be installable.Opera Android: short_name or name is required for a web app to be installable.Samsung Internet: short_name or name is required for a web app to be installable.WebView Android: short_name or name is required for a web app to be installable.
html.manifest.shortcuts 📋Safari3/5/2024880
Chrome: Supported on Windows only.Edge: Supported on Windows only.Opera: Supported on Windows only.
html.manifest.start_url 📋Safari9/18/20231049
Chrome: start_url is required for a web app to be installable.Chrome Android: start_url is required for a web app to be installable.Edge: start_url is required for a web app to be installable.Quest Browser: start_url is required for a web app to be installable.Opera: start_url is required for a web app to be installable.Opera Android: start_url is required for a web app to be installable.Samsung Internet: start_url is required for a web app to be installable.WebView Android: start_url is required for a web app to be installable.
html.manifest.theme_color 📋Safari9/18/20231049