For a given set of browsers, what APIs are not yet in all of them.
| Not in Firefox | Not in Safari | |
|---|---|---|
| In Firefox | 33 | |
| In Safari | 34 |
Below is a list of features that are not in all of Firefox and Safari
| API | First Browser | Date | Days in Limbo | Notes |
|---|---|---|---|---|
| html.elements.a.attributionsourceid 📋 | Safari | 4/26/2021 | 1788 | |
| html.elements.a.coords 📋 | Safari | 6/23/2003 | 8305 | 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.shape 📋 | Safari | 6/23/2003 | 8305 | 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 📋 | Safari | 3/24/2020 | 2186 | |
| html.elements.canvas.moz-opaque | Firefox | 6/30/2009 | 6106 | |
| html.elements.datalist.input_type_color 📋 | Safari | 3/25/2019 | 2551 | |
| html.elements.datalist.input_type_date 📋 | Safari | 4/26/2021 | 1788 | |
| html.elements.datalist.input_type_time 📋 | Safari | 4/26/2021 | 1788 | |
| html.elements.dialog.closedby 📋 | Firefox | 7/22/2025 | 240 | |
| html.elements.form.autocomplete.new-password | Firefox | 5/21/2019 | 2494 | |
| html.elements.iframe.allow.autoplay 📋 | Firefox | 3/10/2020 | 2200 | |
| html.elements.iframe.allow.document-domain 📋 | Firefox | 3/10/2020 | 2200 | |
| html.elements.iframe.allow.encrypted-media 📋 | Firefox | 3/10/2020 | 2200 | |
| html.elements.iframe.allow.fullscreen 📋 | Firefox | 8/25/2020 | 2032 | |
| 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.geolocation 📋 | Firefox | 3/10/2020 | 2200 | |
| html.elements.iframe.allow.midi 📋 | Firefox | 3/10/2020 | 2200 | |
| html.elements.iframe.allow.payment 📋 | Firefox | 3/10/2020 | 2200 | |
| html.elements.iframe.allow.publickey-credentials-create 📋 | Firefox | 2/20/2024 | 758 | |
| html.elements.iframe.allow.publickey-credentials-get 📋 | Firefox | 9/26/2023 | 905 | |
| 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.web-share 📋 | Firefox | 9/22/2020 | 2004 | 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 📋 | Firefox | 9/20/2016 | 3467 | |
| html.elements.iframe.sandbox.allow-presentation 📋 | Firefox | 11/15/2016 | 3411 | |
| html.elements.input.alpha 📋 | Safari | 3/31/2025 | 353 | |
| html.elements.input.colorspace 📋 | Safari | 3/31/2025 | 353 | |
| html.elements.input.switch | Safari | 3/5/2024 | 744 | |
| html.elements.input.type_color.list 📋 | Safari | 3/25/2019 | 2551 | |
| html.elements.input.type_date.list 📋 | Safari | 4/26/2021 | 1788 | |
| html.elements.input.type_password.insecure_login_handling | Firefox | 3/7/2017 | 3299 | |
| html.elements.input.type_range.labeled_values 📋 | Firefox | 6/2/2020 | 2116 | |
| html.elements.input.type_time.list 📋 | Safari | 4/26/2021 | 1788 | |
| html.elements.link.blocking 📋 | Safari | 12/11/2024 | 463 | |
| html.elements.link.rel.alternate_stylesheet 📋 | Firefox | 6/17/2008 | 6484 | |
| html.elements.link.rel.manifest 📋 | Safari | 9/18/2023 | 913 | |
| html.elements.link.rel.modulepreload.as-json 📋 | Safari | 12/12/2025 | 97 | |
| html.elements.link.rel.preload.as-track | Safari | 4/12/2018 | 2898 | |
| html.elements.meta.name.theme-color 📋 | Safari | 9/20/2021 | 1641 | 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 📋 | Safari | 12/11/2024 | 463 | |
| html.elements.script.type.importmap.multiple_import_maps 📋 | Safari | 3/31/2025 | 353 | |
| html.elements.script.type.speculationrules 📋 | Safari | 12/12/2025 | 97 | 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 📋 | Safari | 12/12/2025 | 97 | 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.prefetch 📋 | Safari | 12/12/2025 | 97 | |
| html.elements.script.type.speculationrules.referrer_policy 📋 | Safari | 12/12/2025 | 97 | |
| html.elements.script.type.speculationrules.relative_to 📋 | Safari | 12/12/2025 | 97 | |
| html.elements.script.type.speculationrules.source_optional 📋 | Safari | 12/12/2025 | 97 | |
| html.elements.script.type.speculationrules.tag 📋 | Safari | 12/12/2025 | 97 | |
| html.elements.script.type.speculationrules.urls 📋 | Safari | 12/12/2025 | 97 | |
| html.elements.script.type.speculationrules.where 📋 | Safari | 12/12/2025 | 97 | |
| html.elements.style.blocking 📋 | Safari | 12/11/2024 | 463 | |
| html.elements.summary.display_list_item | Firefox | 9/20/2016 | 3467 | |
| 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.td.rowspan.rowspan_zero | Firefox | 8/8/2017 | 3145 | |
| html.elements.template.shadowrootserializable 📋 | Safari | 9/16/2024 | 549 | |
| html.elements.textarea.autocomplete.new-password | Firefox | 5/21/2019 | 2494 | |
| 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.disableremoteplayback 📋 | Safari | 3/24/2020 | 2186 | |
| html.elements.video.playsinline 📋 | Safari | 9/20/2016 | 3467 | |
| html.global_attributes.autocapitalize 📋 | Firefox | 3/14/2023 | 1101 | |
| html.global_attributes.inert.ignores_find_in_page 📋 | Firefox | 11/21/2023 | 849 | |
| html.global_attributes.is 📋 | Firefox | 10/23/2018 | 2704 | |
| html.global_attributes.writingsuggestions 📋 | Safari | 9/16/2024 | 549 |