For a given set of browsers, what APIs are not yet in all of them.
| Not in Chrome | Not in Firefox | |
|---|---|---|
| In Chrome | 110 | |
| In Firefox | 19 |
Below is a list of features that are not in all of Chrome and Firefox
| API | First Browser | Date | Days in Limbo | Notes |
|---|---|---|---|---|
| html.elements.a.attributionsrc 📋 | Chrome | 5/14/2024 | 674 | |
| html.elements.a.coords 📋 | Chrome | 12/11/2008 | 6307 | 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 | Firefox | 4/24/2012 | 5077 | |
| html.elements.a.hreftranslate | Chrome | 4/7/2020 | 2172 | |
| html.elements.a.interestfor | Chrome | 10/28/2025 | 142 | |
| html.elements.a.referrerpolicy.no-referrer-when-downgrade | Chrome | 5/25/2016 | 3585 | |
| html.elements.a.referrerpolicy.origin-when-cross-origin | Chrome | 5/25/2016 | 3585 | |
| html.elements.a.referrerpolicy.unsafe-url | Chrome | 5/25/2016 | 3585 | |
| html.elements.a.shape 📋 | Chrome | 12/11/2008 | 6307 | 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.target.unfencedTop | Chrome | 6/11/2024 | 646 | |
| html.elements.area.attributionsrc 📋 | Chrome | 5/14/2024 | 674 | |
| html.elements.area.interestfor | Chrome | 10/28/2025 | 142 | |
| html.elements.area.referrerpolicy.no-referrer-when-downgrade | Chrome | 5/25/2016 | 3585 | |
| html.elements.area.referrerpolicy.origin-when-cross-origin | Chrome | 5/25/2016 | 3585 | |
| html.elements.area.referrerpolicy.unsafe-url | Chrome | 5/25/2016 | 3585 | |
| html.elements.audio.controlslist 📋 | Chrome | 4/19/2017 | 3256 | |
| html.elements.audio.disableremoteplayback 📋 | Chrome | 1/23/2024 | 786 | |
| html.elements.button.interestfor | Chrome | 10/28/2025 | 142 | |
| html.elements.canvas.moz-opaque | Firefox | 6/30/2009 | 6106 | |
| html.elements.datalist.input_type_color 📋 | Chrome | 6/26/2012 | 5014 | |
| html.elements.datalist.input_type_date 📋 | Chrome | 6/26/2012 | 5014 | |
| html.elements.datalist.input_type_time 📋 | Chrome | 6/26/2012 | 5014 | |
| html.elements.fencedframe 📋 | Chrome | 6/11/2024 | 646 | |
| html.elements.fencedframe.allow 📋 | Chrome | 6/11/2024 | 646 | |
| html.elements.fencedframe.height 📋 | Chrome | 6/11/2024 | 646 | |
| html.elements.fencedframe.width 📋 | Chrome | 6/11/2024 | 646 | |
| html.elements.form.autocomplete.new-password | Firefox | 5/21/2019 | 2494 | |
| html.elements.geolocation 📋 | Chrome | 1/13/2026 | 65 | |
| html.elements.geolocation.autolocate 📋 | Chrome | 1/13/2026 | 65 | |
| html.elements.geolocation.watch 📋 | Chrome | 1/13/2026 | 65 | |
| html.elements.h1.no_ua_styles_in_article_aside_nav_section 📋 | Firefox | 6/24/2025 | 268 | |
| html.elements.iframe.allow.accelerometer 📋 | Chrome | 4/17/2018 | 2893 | |
| html.elements.iframe.allow.ambient-light-sensor 📋 | Chrome | 4/17/2018 | 2893 | |
| html.elements.iframe.allow.attribution-reporting 📋 | Chrome | 9/12/2023 | 919 | |
| html.elements.iframe.allow.bluetooth 📋 | Chrome | 8/2/2022 | 1325 | |
| html.elements.iframe.allow.browsing-topics | Chrome | 7/18/2023 | 975 | |
| html.elements.iframe.allow.compute-pressure 📋 | Chrome | 5/14/2024 | 674 | |
| html.elements.iframe.allow.cross-origin-isolated 📋 | Chrome | 11/17/2020 | 1948 | |
| html.elements.iframe.allow.gamepad 📋 | Firefox | 8/10/2021 | 1682 | 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.gyroscope 📋 | Chrome | 4/17/2018 | 2893 | |
| html.elements.iframe.allow.hid 📋 | Chrome | 3/2/2021 | 1843 | |
| html.elements.iframe.allow.identity-credentials-get 📋 | Chrome | 2/7/2023 | 1136 | |
| html.elements.iframe.allow.idle-detection 📋 | Chrome | 9/21/2021 | 1640 | |
| html.elements.iframe.allow.local-fonts 📋 | Chrome | 6/21/2022 | 1367 | |
| html.elements.iframe.allow.magnetometer 📋 | Chrome | 4/17/2018 | 2893 | |
| html.elements.iframe.allow.otp-credentials 📋 | Chrome | 8/31/2021 | 1661 | |
| html.elements.iframe.allow.picture-in-picture 📋 | Chrome | 9/4/2018 | 2753 | |
| html.elements.iframe.allow.publickey-credentials-create 📋 | Firefox | 2/20/2024 | 758 | |
| html.elements.iframe.allow.serial 📋 | Chrome | 3/2/2021 | 1843 | |
| html.elements.iframe.allow.speaker-selection 📋 | Firefox | 8/1/2023 | 961 | Firefox for Android: Not available due to a limitation in Android (see bug 1473346). |
| html.elements.iframe.allow.storage-access 📋 | Chrome | 5/2/2023 | 1052 | |
| html.elements.iframe.allow.usb 📋 | Chrome | 7/25/2017 | 3159 | |
| html.elements.iframe.allow.wildcards | Chrome | 11/29/2022 | 1206 | |
| html.elements.iframe.allow.window-management 📋 | Chrome | 3/29/2022 | 1451 | |
| html.elements.iframe.allow.xr-spatial-tracking 📋 | Chrome | 12/10/2019 | 2291 | |
| html.elements.iframe.allowpaymentrequest | Chrome | 7/25/2017 | 3159 | |
| html.elements.iframe.browsingtopics | Chrome | 6/11/2024 | 646 | |
| html.elements.iframe.credentialless 📋 | Chrome | 2/7/2023 | 1136 | |
| html.elements.iframe.csp 📋 | Chrome | 9/5/2017 | 3117 | |
| html.elements.iframe.privateToken 📋 | Chrome | 9/12/2023 | 919 | |
| html.elements.iframe.referrerpolicy.no-referrer-when-downgrade | Chrome | 5/25/2016 | 3585 | |
| html.elements.iframe.referrerpolicy.origin-when-cross-origin | Chrome | 5/25/2016 | 3585 | |
| html.elements.iframe.referrerpolicy.unsafe-url | Chrome | 5/25/2016 | 3585 | |
| html.elements.iframe.sandbox.allow-top-navigation-to-custom-protocols 📋 | Firefox | 5/31/2022 | 1388 | |
| html.elements.img.attributionsrc 📋 | Chrome | 5/14/2024 | 674 | |
| html.elements.img.referrerpolicy.no-referrer-when-downgrade | Chrome | 5/25/2016 | 3585 | |
| html.elements.img.referrerpolicy.origin-when-cross-origin | Chrome | 5/25/2016 | 3585 | |
| html.elements.img.referrerpolicy.unsafe-url | Chrome | 5/25/2016 | 3585 | |
| html.elements.img.sizes.auto 📋 | Chrome | 6/11/2024 | 646 | |
| html.elements.input.type_color.accepts_css_colors 📋 | Firefox | 9/16/2025 | 184 | |
| html.elements.input.type_color.list 📋 | Chrome | 6/26/2012 | 5014 | |
| html.elements.input.type_date.list 📋 | Chrome | 6/26/2012 | 5014 | |
| html.elements.input.type_month 📋 | Chrome | 6/26/2012 | 5014 | Safari: The input type is recognized, but there is no month-specific control. See bug 200416. |
| html.elements.input.type_password.insecure_login_handling | Firefox | 3/7/2017 | 3299 | |
| html.elements.input.type_time.list 📋 | Chrome | 6/26/2012 | 5014 | |
| html.elements.input.type_week 📋 | Chrome | 6/26/2012 | 5014 | |
| html.elements.link.blocking 📋 | Chrome | 9/2/2022 | 1294 | |
| html.elements.link.referrerpolicy.no-referrer-when-downgrade | Chrome | 5/25/2016 | 3585 | |
| html.elements.link.referrerpolicy.origin-when-cross-origin | Chrome | 5/25/2016 | 3585 | |
| html.elements.link.referrerpolicy.unsafe-url | Chrome | 5/25/2016 | 3585 | |
| html.elements.link.rel.alternate_stylesheet 📋 | Firefox | 6/17/2008 | 6484 | |
| html.elements.link.rel.compression-dictionary 📋 | Chrome | 10/15/2024 | 520 | |
| html.elements.link.rel.expect 📋 | Chrome | 4/16/2024 | 702 | |
| html.elements.link.rel.manifest 📋 | Chrome | 11/18/2014 | 4139 | |
| html.elements.link.rel.modulepreload.as-json 📋 | Chrome | 4/7/2026 | -19 | |
| html.elements.link.rel.modulepreload.as-style 📋 | Chrome | 4/7/2026 | -19 | |
| html.elements.link.rel.preload.as-track | Chrome | 4/13/2016 | 3627 | |
| html.elements.link.rel.prerender | Chrome | 12/6/2017 | 3025 | Chrome: Does not trigger prerendering. Triggers NoState Prefetch instead. See blog post.Chrome Android: Does not trigger prerendering. Triggers NoState Prefetch instead. See blog post.Edge: Does not trigger prerendering. Triggers NoState Prefetch instead. See blog post.Quest Browser: Does not trigger prerendering. Triggers NoState Prefetch instead. See blog post.Opera: Does not trigger prerendering. Triggers NoState Prefetch instead. See blog post.Opera Android: Does not trigger prerendering. Triggers NoState Prefetch instead. See blog post.WebView Android: Does not trigger prerendering. Triggers NoState Prefetch instead. See blog post. |
| html.elements.meta.name.application-title | Chrome | 3/4/2025 | 380 | |
| html.elements.meta.name.theme-color 📋 | Chrome | 3/12/2019 | 2564 | 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.attributionsrc 📋 | Chrome | 5/14/2024 | 674 | |
| html.elements.script.blocking 📋 | Chrome | 9/2/2022 | 1294 | |
| html.elements.script.referrerpolicy.no-referrer-when-downgrade | Chrome | 10/16/2018 | 2711 | |
| html.elements.script.referrerpolicy.origin-when-cross-origin | Chrome | 10/16/2018 | 2711 | |
| html.elements.script.referrerpolicy.unsafe-url | Chrome | 10/16/2018 | 2711 | |
| html.elements.script.type.importmap.multiple_import_maps 📋 | Chrome | 2/4/2025 | 408 | |
| html.elements.script.type.speculationrules 📋 | Chrome | 1/10/2023 | 1164 | Chrome: Initial support included same-origin prerendering only.Chrome Android: Initial support included same-origin prerendering only.Edge: Initial support included same-origin prerendering only.Quest Browser: Initial support included same-origin prerendering only.Opera: Initial support included same-origin prerendering only.Opera Android: Initial support included same-origin prerendering only.Samsung Internet: Initial support included same-origin prerendering only.WebView Android: Initial support included same-origin prerendering only. |
| html.elements.script.type.speculationrules.eagerness 📋 | Chrome | 1/23/2024 | 786 | Safari: Only conservative is supported for document rules (though moderate automatically falls back to conservative). Only eager and immediate is supported for list rules.Safari on iOS: Only conservative is supported for document rules (though moderate automatically falls back to conservative). Only eager and immediate is supported for list rules. |
| html.elements.script.type.speculationrules.expects_no_vary_search 📋 | Chrome | 7/23/2024 | 604 | Chrome: Supported for prefetch only.Chrome Android: Supported for prefetch only.Edge: Supported for prefetch only.Opera: Supported for prefetch only.Opera Android: Supported for prefetch only.Samsung Internet: Supported for prefetch only.WebView Android: Supported for prefetch only. |
| html.elements.script.type.speculationrules.prefetch 📋 | Chrome | 2/7/2023 | 1136 | |
| html.elements.script.type.speculationrules.prerender 📋 | Chrome | 9/2/2022 | 1294 | |
| html.elements.script.type.speculationrules.referrer_policy 📋 | Chrome | 3/7/2023 | 1108 | |
| html.elements.script.type.speculationrules.relative_to 📋 | Chrome | 1/23/2024 | 786 | |
| html.elements.script.type.speculationrules.requires 📋 | Chrome | 2/7/2023 | 1136 | |
| html.elements.script.type.speculationrules.requires.anonymous-client-ip-when-cross-origin 📋 | Chrome | 2/7/2023 | 1136 | |
| html.elements.script.type.speculationrules.source_optional 📋 | Chrome | 2/20/2024 | 758 | |
| html.elements.script.type.speculationrules.tag 📋 | Chrome | 4/29/2025 | 324 | |
| html.elements.script.type.speculationrules.target_hint 📋 | Chrome | 6/24/2025 | 268 | Chrome: Only "_blank" and "_self" are supported and only for prefetch.Chrome Android: Only "_blank" and "_self" are supported and only for prefetch.Edge: Only "_blank" and "_self" are supported and only for prefetch.Opera: Only "_blank" and "_self" are supported and only for prefetch.Opera Android: Only "_blank" and "_self" are supported and only for prefetch.WebView Android: Only "_blank" and "_self" are supported and only for prefetch. |
| html.elements.script.type.speculationrules.urls 📋 | Chrome | 1/10/2023 | 1164 | |
| html.elements.script.type.speculationrules.where 📋 | Chrome | 1/23/2024 | 786 | |
| html.elements.selectedcontent 📋 | Chrome | 4/1/2025 | 352 | |
| html.elements.style.blocking 📋 | Chrome | 9/2/2022 | 1294 | |
| html.elements.tbody.charoff | Firefox | 11/9/2004 | 7800 | Chrome: Since Chrome 1, the attribute can be set, but has no effect.Chrome Android: Since Chrome Android 18, the attribute can be set, but has no effect.Edge: Since Edge 79, the attribute can be set, but has no effect.Quest Browser: Since Quest Browser 5.0, the attribute can be set, but has no effect.Opera: Since Opera 15, the attribute can be set, but has no effect.Opera Android: Since Opera Android 14, the attribute can be set, but has no effect.Safari: Since Safari 3, the attribute can be set, but has no effect.Safari on iOS: Since Safari on iOS 2, the attribute can be set, but has no effect.Samsung Internet: Since Samsung Internet 1.0, the attribute can be set, but has no effect.WebView Android: Since WebView Android 4.4, the attribute can be set, but has no effect.WebView on iOS: Since WebView on iOS 2, the attribute can be set, but has no effect. |
| html.elements.td.charoff | Firefox | 11/9/2004 | 7800 | Chrome: Since Chrome 1, the attribute can be set, but has no effect.Chrome Android: Since Chrome Android 18, the attribute can be set, but has no effect.Edge: Since Edge 79, the attribute can be set, but has no effect.Quest Browser: Since Quest Browser 5.0, the attribute can be set, but has no effect.Opera: Since Opera 15, the attribute can be set, but has no effect.Opera Android: Since Opera Android 14, the attribute can be set, but has no effect.Safari: Since Safari 3, the attribute can be set, but has no effect.Safari on iOS: Since Safari on iOS 2, the attribute can be set, but has no effect.Samsung Internet: Since Samsung Internet 1.0, the attribute can be set, but has no effect.WebView Android: Since WebView Android 4.4, the attribute can be set, but has no effect.WebView on iOS: Since WebView on iOS 2, the attribute can be set, but has no effect. |
| html.elements.template.shadowrootserializable 📋 | Chrome | 5/14/2024 | 674 | |
| html.elements.textarea.autocomplete.new-password | Firefox | 5/21/2019 | 2494 | |
| html.elements.textarea.autocomplete.webauthn 📋 | Chrome | 11/29/2022 | 1206 | |
| html.elements.textarea.wrap.hard | Chrome | 12/13/2011 | 5210 | |
| html.elements.tfoot.charoff | Firefox | 11/9/2004 | 7800 | Chrome: Since Chrome 1, the attribute can be set, but has no effect.Chrome Android: Since Chrome Android 18, the attribute can be set, but has no effect.Edge: Since Edge 79, the attribute can be set, but has no effect.Quest Browser: Since Quest Browser 5.0, the attribute can be set, but has no effect.Opera: Since Opera 15, the attribute can be set, but has no effect.Opera Android: Since Opera Android 14, the attribute can be set, but has no effect.Safari: Since Safari 3, the attribute can be set, but has no effect.Safari on iOS: Since Safari on iOS 2, the attribute can be set, but has no effect.Samsung Internet: Since Samsung Internet 1.0, the attribute can be set, but has no effect.WebView Android: Since WebView Android 4.4, the attribute can be set, but has no effect.WebView on iOS: Since WebView on iOS 2, the attribute can be set, but has no effect. |
| html.elements.th.charoff | Firefox | 11/9/2004 | 7800 | Chrome: Since Chrome 1, the attribute can be set, but has no effect.Chrome Android: Since Chrome Android 18, the attribute can be set, but has no effect.Edge: Since Edge 79, the attribute can be set, but has no effect.Quest Browser: Since Quest Browser 5.0, the attribute can be set, but has no effect.Opera: Since Opera 15, the attribute can be set, but has no effect.Opera Android: Since Opera Android 14, the attribute can be set, but has no effect.Safari: Since Safari 3, the attribute can be set, but has no effect.Safari on iOS: Since Safari on iOS 2, the attribute can be set, but has no effect.Samsung Internet: Since Samsung Internet 1.0, the attribute can be set, but has no effect.WebView Android: Since WebView Android 4.4, the attribute can be set, but has no effect.WebView on iOS: Since WebView on iOS 2, the attribute can be set, but has no effect. |
| html.elements.th.rowspan.rowspan_zero | Firefox | 8/8/2017 | 3145 | |
| html.elements.thead.charoff | Firefox | 11/9/2004 | 7800 | Chrome: Since Chrome 1, the attribute can be set, but has no effect.Chrome Android: Since Chrome Android 18, the attribute can be set, but has no effect.Edge: Since Edge 79, the attribute can be set, but has no effect.Quest Browser: Since Quest Browser 5.0, the attribute can be set, but has no effect.Opera: Since Opera 15, the attribute can be set, but has no effect.Opera Android: Since Opera Android 14, the attribute can be set, but has no effect.Safari: Since Safari 3, the attribute can be set, but has no effect.Safari on iOS: Since Safari on iOS 2, the attribute can be set, but has no effect.Samsung Internet: Since Samsung Internet 1.0, the attribute can be set, but has no effect.WebView Android: Since WebView Android 4.4, the attribute can be set, but has no effect.WebView on iOS: Since WebView on iOS 2, the attribute can be set, but has no effect. |
| html.elements.video.controlslist 📋 | Chrome | 4/19/2017 | 3256 | |
| html.elements.video.disableremoteplayback 📋 | Chrome | 1/23/2024 | 786 | |
| html.elements.video.playsinline 📋 | Chrome | 6/4/2019 | 2480 | |
| html.global_attributes.autocorrect 📋 | Firefox | 3/4/2025 | 380 | |
| html.global_attributes.popover.hint 📋 | Chrome | 2/4/2025 | 408 | |
| html.global_attributes.virtualkeyboardpolicy 📋 | Chrome | 9/21/2021 | 1640 | |
| html.global_attributes.writingsuggestions 📋 | Chrome | 4/16/2024 | 702 |