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 Safari
| API | First Browser | Date | Last Browser | Date | Days in experimentation | Notes |
|---|---|---|---|---|---|---|
| html.elements.a.attributionsourceid 📋 | Safari | 4/26/2021 | 1788 | |||
| html.elements.a.interestfor | Edge | 10/31/2025 | 139 | |||
| html.elements.a.target.unfencedTop | Edge | 6/13/2024 | 644 | |||
| html.elements.area.interestfor | Edge | 10/31/2025 | 139 | |||
| html.elements.button.interestfor | Edge | 10/31/2025 | 139 | |||
| html.elements.fencedframe 📋 | Edge | 6/13/2024 | 644 | |||
| html.elements.fencedframe.allow 📋 | Edge | 6/13/2024 | 644 | |||
| html.elements.fencedframe.height 📋 | Edge | 6/13/2024 | 644 | |||
| html.elements.fencedframe.width 📋 | Edge | 6/13/2024 | 644 | |||
| html.elements.geolocation 📋 | Edge | 1/21/2026 | 57 | |||
| html.elements.geolocation.autolocate 📋 | Edge | 1/21/2026 | 57 | |||
| html.elements.geolocation.watch 📋 | Edge | 1/21/2026 | 57 | |||
| html.elements.iframe.allow.accelerometer 📋 | Edge | 1/15/2020 | 2255 | |||
| html.elements.iframe.allow.ambient-light-sensor 📋 | Edge | 1/15/2020 | 2255 | |||
| html.elements.iframe.allow.bluetooth 📋 | Edge | 8/5/2022 | 1322 | |||
| html.elements.iframe.allow.compute-pressure 📋 | Edge | 5/17/2024 | 671 | |||
| html.elements.iframe.allow.cross-origin-isolated 📋 | Edge | 11/19/2020 | 1946 | |||
| html.elements.iframe.allow.document-domain 📋 | Edge | 1/15/2020 | 2255 | |||
| html.elements.iframe.allow.gyroscope 📋 | Edge | 1/15/2020 | 2255 | |||
| html.elements.iframe.allow.hid 📋 | Edge | 3/4/2021 | 1841 | |||
| html.elements.iframe.allow.identity-credentials-get 📋 | Edge | 2/9/2023 | 1134 | |||
| html.elements.iframe.allow.idle-detection 📋 | Edge | 9/24/2021 | 1637 | |||
| html.elements.iframe.allow.local-fonts 📋 | Edge | 6/23/2022 | 1365 | |||
| html.elements.iframe.allow.magnetometer 📋 | Edge | 1/15/2020 | 2255 | |||
| html.elements.iframe.allow.otp-credentials 📋 | Edge | 9/2/2021 | 1659 | |||
| html.elements.iframe.allow.picture-in-picture 📋 | Edge | 1/15/2020 | 2255 | |||
| html.elements.iframe.allow.serial 📋 | Edge | 3/4/2021 | 1841 | |||
| html.elements.iframe.allow.storage-access 📋 | Edge | 5/5/2023 | 1049 | |||
| html.elements.iframe.allow.usb 📋 | Edge | 1/15/2020 | 2255 | |||
| html.elements.iframe.allow.wildcards | Edge | 12/5/2022 | 1200 | |||
| html.elements.iframe.allow.window-management 📋 | Edge | 4/1/2022 | 1448 | |||
| html.elements.iframe.allow.xr-spatial-tracking 📋 | Edge | 1/15/2020 | 2255 | |||
| html.elements.iframe.credentialless 📋 | Edge | 2/9/2023 | 1134 | |||
| html.elements.iframe.csp 📋 | Edge | 1/15/2020 | 2255 | |||
| html.elements.iframe.privateToken 📋 | Edge | 9/15/2023 | 916 | |||
| 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.link.rel.compression-dictionary 📋 | Edge | 10/17/2024 | 518 | |||
| html.elements.link.rel.expect 📋 | Edge | 4/18/2024 | 700 | |||
| html.elements.link.rel.modulepreload.as-style 📋 | Edge | 4/9/2026 | -21 | |||
| html.elements.meta.name.application-title | Edge | 3/6/2025 | 378 | |||
| html.elements.script.type.speculationrules 📋 | Edge | 1/12/2023 | Safari | 12/12/2025 | 1065 | 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 📋 | Edge | 1/25/2024 | Safari | 12/12/2025 | 687 | 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 📋 | Edge | 7/25/2024 | 602 | 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 📋 | Edge | 2/9/2023 | Safari | 12/12/2025 | 1037 | |
| html.elements.script.type.speculationrules.prerender 📋 | Edge | 9/1/2022 | 1295 | |||
| html.elements.script.type.speculationrules.referrer_policy 📋 | Edge | 3/13/2023 | Safari | 12/12/2025 | 1005 | |
| html.elements.script.type.speculationrules.relative_to 📋 | Edge | 1/25/2024 | Safari | 12/12/2025 | 687 | |
| html.elements.script.type.speculationrules.requires 📋 | Edge | 2/9/2023 | 1134 | |||
| html.elements.script.type.speculationrules.source_optional 📋 | Edge | 2/23/2024 | Safari | 12/12/2025 | 658 | |
| html.elements.script.type.speculationrules.tag 📋 | Edge | 5/1/2025 | Safari | 12/12/2025 | 225 | |
| html.elements.script.type.speculationrules.target_hint 📋 | Edge | 6/26/2025 | 266 | 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 📋 | Edge | 1/12/2023 | Safari | 12/12/2025 | 1065 | |
| html.elements.script.type.speculationrules.where 📋 | Edge | 1/25/2024 | Safari | 12/12/2025 | 687 | |
| html.elements.selectedcontent 📋 | Edge | 4/4/2025 | 349 | |||
| html.elements.template.shadowrootreferencetarget | Edge | 2/6/2025 | Safari | 9/15/2025 | 221 | |
| html.elements.textarea.autocomplete.webauthn 📋 | Edge | 12/5/2022 | 1200 | |||
| html.global_attributes.popover.hint 📋 | Edge | 2/6/2025 | 406 | |||
| html.global_attributes.virtualkeyboardpolicy 📋 | Edge | 9/24/2021 | 1637 |