For a given set of browsers what APIs are still considred experimental, and how long have they been experimental?
Below is a list of features that are marked as "Experimental" in Edge and Firefox
| API | First Browser | Date | Last Browser | Date | Days in experimentation | Notes |
|---|---|---|---|---|---|---|
| html.elements.a.attributionsrc 📋 | Edge | 5/17/2024 | 807 | |||
| html.elements.a.target.unfencedTop | Edge | 7/21/2023 | 1108 | |||
| html.elements.fencedframe 📋 | Edge | 7/21/2023 | 1108 | |||
| html.elements.fencedframe.allow 📋 | Edge | 7/21/2023 | 1108 | |||
| html.elements.fencedframe.height 📋 | Edge | 7/21/2023 | 1108 | |||
| html.elements.fencedframe.width 📋 | Edge | 7/21/2023 | 1108 | |||
| html.elements.form.autocomplete.webauthn 📋 | Edge | 12/5/2022 | 1336 | |||
| html.elements.iframe.allow.accelerometer 📋 | Edge | 1/15/2020 | 2391 | |||
| html.elements.iframe.allow.ambient-light-sensor 📋 | Edge | 1/15/2020 | 2391 | |||
| html.elements.iframe.allow.attribution-reporting 📋 | Edge | 9/15/2023 | 1052 | |||
| html.elements.iframe.allow.bluetooth 📋 | Edge | 8/5/2022 | 1458 | |||
| html.elements.iframe.allow.browsing-topics | Edge | 7/21/2023 | 1108 | |||
| html.elements.iframe.allow.compute-pressure 📋 | Edge | 5/17/2024 | 807 | |||
| html.elements.iframe.allow.cross-origin-isolated 📋 | Edge | 11/19/2020 | 2082 | |||
| html.elements.iframe.allow.document-domain 📋 | Edge | 1/15/2020 | Firefox | 3/10/2020 | 55 | |
| html.elements.iframe.allow.gamepad 📋 | Firefox | 8/10/2021 | 1818 | 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 📋 | Edge | 1/15/2020 | 2391 | |||
| html.elements.iframe.allow.hid 📋 | Edge | 3/4/2021 | 1977 | |||
| html.elements.iframe.allow.identity-credentials-get 📋 | Edge | 2/9/2023 | 1270 | |||
| html.elements.iframe.allow.idle-detection 📋 | Edge | 9/24/2021 | 1773 | |||
| html.elements.iframe.allow.local-fonts 📋 | Edge | 6/23/2022 | 1501 | |||
| html.elements.iframe.allow.magnetometer 📋 | Edge | 1/15/2020 | 2391 | |||
| html.elements.iframe.allow.otp-credentials 📋 | Edge | 9/2/2021 | 1795 | |||
| html.elements.iframe.allow.serial 📋 | Edge | 3/4/2021 | 1977 | |||
| html.elements.iframe.allow.speaker-selection 📋 | Firefox | 8/1/2023 | 1097 | Firefox for Android: Not available due to a limitation in Android (see bug 1473346). | ||
| html.elements.iframe.allow.storage-access 📋 | Edge | 5/5/2023 | 1185 | |||
| html.elements.iframe.allow.usb 📋 | Edge | 1/15/2020 | 2391 | |||
| html.elements.iframe.allow.wildcards | Edge | 12/5/2022 | 1336 | |||
| html.elements.iframe.allow.window-management 📋 | Edge | 4/1/2022 | 1584 | |||
| html.elements.iframe.allow.xr-spatial-tracking 📋 | Edge | 1/15/2020 | 2391 | |||
| html.elements.iframe.browsingtopics | Edge | 7/21/2023 | 1108 | |||
| html.elements.iframe.credentialless 📋 | Edge | 2/9/2023 | 1270 | |||
| html.elements.iframe.csp 📋 | Edge | 1/15/2020 | 2391 | |||
| html.elements.img.attributionsrc 📋 | Edge | 5/17/2024 | 807 | |||
| html.elements.link.rel.expect 📋 | Edge | 4/18/2024 | 836 | |||
| html.elements.meta.name.application-title | Edge | 3/6/2025 | 514 | |||
| html.elements.script.attributionsrc 📋 | Edge | 5/17/2024 | 807 | |||
| html.elements.script.type.importmap.multiple_import_maps 📋 | Edge | 2/6/2025 | 542 | |||
| html.elements.script.type.speculationrules 📋 | Edge | 1/12/2023 | 1298 | 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. | ||
| html.elements.script.type.speculationrules.eagerness | Edge | 1/25/2024 | 920 | |||
| html.elements.script.type.speculationrules.expects_no_vary_search | Edge | 7/25/2024 | 738 | 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. | ||
| html.elements.script.type.speculationrules.prefetch | Edge | 2/9/2023 | 1270 | |||
| html.elements.script.type.speculationrules.prerender | Edge | 9/1/2022 | 1431 | |||
| html.elements.script.type.speculationrules.referrer_policy | Edge | 3/13/2023 | 1238 | |||
| html.elements.script.type.speculationrules.relative_to | Edge | 1/25/2024 | 920 | |||
| html.elements.script.type.speculationrules.requires | Edge | 2/9/2023 | 1270 | |||
| html.elements.script.type.speculationrules.source_optional | Edge | 2/23/2024 | 891 | |||
| html.elements.script.type.speculationrules.urls | Edge | 1/12/2023 | 1298 | |||
| html.elements.script.type.speculationrules.where | Edge | 1/25/2024 | 920 | |||
| html.elements.template.shadowrootserializable 📋 | Edge | 5/17/2024 | 807 | |||
| html.elements.textarea.autocomplete.webauthn 📋 | Edge | 12/5/2022 | 1336 | |||
| html.global_attributes.hidden.until-found 📋 | Edge | 5/31/2022 | 1524 | |||
| html.global_attributes.virtualkeyboardpolicy 📋 | Edge | 9/24/2021 | 1773 | |||
| html.manifest.display_override 📋 | Edge | 3/4/2021 | 1977 | Chrome: display_override and/or display are required for a web app to be installable.Chrome Android: display_override and/or display are required for a web app to be installable.Edge: display_override and/or display are required for a web app to be installable.Quest Browser: display_override and/or display are required for a web app to be installable.Opera: display_override and/or display are required for a web app to be installable.Opera Android: display_override and/or display are required for a web app to be installable.Samsung Internet: display_override and/or display are required for a web app to be installable. | ||
| html.manifest.display_override.tabbed 📋 | Edge | 6/13/2024 | 780 | |||
| html.manifest.display_override.window-controls-overlay 📋 | Edge | 9/1/2022 | 1431 | |||
| html.manifest.file_handlers 📋 | Edge | 5/31/2022 | 1524 | |||
| html.manifest.launch_handler 📋 | Edge | 2/9/2023 | 1270 | |||
| html.manifest.launch_handler.client_mode 📋 | Edge | 2/9/2023 | 1270 | |||
| html.manifest.note_taking 📋 | Edge | 10/21/2021 | 1746 | |||
| html.manifest.note_taking.new_note_url 📋 | Edge | 10/21/2021 | 1746 | |||
| html.manifest.protocol_handlers 📋 | Edge | 11/19/2021 | 1717 | |||
| html.manifest.protocol_handlers.protocol 📋 | Edge | 11/19/2021 | 1717 | |||
| html.manifest.protocol_handlers.url 📋 | Edge | 11/19/2021 | 1717 | |||
| html.manifest.serviceworker | Edge | 1/15/2020 | 2391 | |||
| html.manifest.serviceworker.scope | Edge | 1/15/2020 | 2391 | |||
| html.manifest.serviceworker.src | Edge | 1/15/2020 | 2391 | |||
| html.manifest.serviceworker.use_cache | Edge | 1/15/2020 | 2391 | |||
| html.manifest.share_target 📋 | Edge | 3/4/2021 | 1977 | Firefox for Android: The property parses, but has no effect. |