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 Chrome and Chrome Android
| API | First Browser | Date | Last Browser | Date | Days in experimentation | Notes |
|---|---|---|---|---|---|---|
| html.elements.a.hreftranslate | Chrome | 4/7/2020 | Chrome Android | 4/7/2020 | 0 | |
| html.elements.a.interestfor | Chrome | 10/28/2025 | Chrome Android | 10/28/2025 | 0 | |
| html.elements.a.target.unfencedTop | Chrome | 6/11/2024 | Chrome Android | 6/11/2024 | 0 | |
| html.elements.area.interestfor | Chrome | 10/28/2025 | Chrome Android | 10/28/2025 | 0 | |
| html.elements.button.interestfor | Chrome | 10/28/2025 | Chrome Android | 10/28/2025 | 0 | |
| html.elements.fencedframe 📋 | Chrome | 6/11/2024 | Chrome Android | 6/11/2024 | 0 | |
| html.elements.fencedframe.allow 📋 | Chrome | 6/11/2024 | Chrome Android | 6/11/2024 | 0 | |
| html.elements.fencedframe.height 📋 | Chrome | 6/11/2024 | Chrome Android | 6/11/2024 | 0 | |
| html.elements.fencedframe.width 📋 | Chrome | 6/11/2024 | Chrome Android | 6/11/2024 | 0 | |
| html.elements.geolocation 📋 | Chrome | 1/13/2026 | Chrome Android | 1/13/2026 | 0 | |
| html.elements.geolocation.autolocate 📋 | Chrome | 1/13/2026 | Chrome Android | 1/13/2026 | 0 | |
| html.elements.geolocation.watch 📋 | Chrome | 1/13/2026 | Chrome Android | 1/13/2026 | 0 | |
| html.elements.iframe.allow.accelerometer 📋 | Chrome | 4/17/2018 | Chrome Android | 4/17/2018 | 0 | |
| html.elements.iframe.allow.ambient-light-sensor 📋 | Chrome | 4/17/2018 | Chrome Android | 4/17/2018 | 0 | |
| html.elements.iframe.allow.bluetooth 📋 | Chrome | 8/2/2022 | Chrome Android | 8/2/2022 | 0 | |
| html.elements.iframe.allow.compute-pressure 📋 | Chrome | 5/14/2024 | 674 | |||
| html.elements.iframe.allow.cross-origin-isolated 📋 | Chrome | 11/17/2020 | Chrome Android | 11/17/2020 | 0 | |
| html.elements.iframe.allow.document-domain 📋 | Chrome | 1/23/2018 | 2977 | |||
| html.elements.iframe.allow.gyroscope 📋 | Chrome | 4/17/2018 | Chrome Android | 4/17/2018 | 0 | |
| html.elements.iframe.allow.hid 📋 | Chrome | 3/2/2021 | Chrome Android | 3/2/2021 | 0 | |
| html.elements.iframe.allow.identity-credentials-get 📋 | Chrome | 2/7/2023 | Chrome Android | 2/7/2023 | 0 | |
| html.elements.iframe.allow.idle-detection 📋 | Chrome | 9/21/2021 | Chrome Android | 9/21/2021 | 0 | |
| html.elements.iframe.allow.local-fonts 📋 | Chrome | 6/21/2022 | 1367 | |||
| html.elements.iframe.allow.magnetometer 📋 | Chrome | 4/17/2018 | Chrome Android | 4/17/2018 | 0 | |
| html.elements.iframe.allow.otp-credentials 📋 | Chrome Android | 7/27/2020 | Chrome | 8/31/2021 | 400 | |
| html.elements.iframe.allow.picture-in-picture 📋 | Chrome | 9/4/2018 | Chrome Android | 9/2/2022 | 1459 | |
| html.elements.iframe.allow.serial 📋 | Chrome | 3/2/2021 | Chrome Android | 3/2/2021 | 0 | |
| html.elements.iframe.allow.storage-access 📋 | Chrome | 5/2/2023 | Chrome Android | 5/2/2023 | 0 | |
| html.elements.iframe.allow.usb 📋 | Chrome | 7/25/2017 | Chrome Android | 8/1/2017 | 7 | |
| html.elements.iframe.allow.wildcards | Chrome | 11/29/2022 | Chrome Android | 11/29/2022 | 0 | |
| html.elements.iframe.allow.window-management 📋 | Chrome | 3/29/2022 | Chrome Android | 3/29/2022 | 0 | |
| html.elements.iframe.allow.xr-spatial-tracking 📋 | Chrome | 12/10/2019 | Chrome Android | 12/17/2019 | 7 | |
| html.elements.iframe.credentialless 📋 | Chrome | 2/7/2023 | Chrome Android | 2/7/2023 | 0 | |
| html.elements.iframe.csp 📋 | Chrome | 9/5/2017 | Chrome Android | 9/5/2017 | 0 | |
| html.elements.iframe.privateToken 📋 | Chrome | 9/12/2023 | Chrome Android | 9/12/2023 | 0 | |
| html.elements.link.rel.compression-dictionary 📋 | Chrome | 10/15/2024 | Chrome Android | 10/15/2024 | 0 | |
| html.elements.link.rel.expect 📋 | Chrome | 4/16/2024 | Chrome Android | 4/16/2024 | 0 | |
| html.elements.link.rel.modulepreload.as-style 📋 | Chrome | 4/7/2026 | Chrome Android | 4/7/2026 | 0 | |
| html.elements.meta.name.application-title | Chrome | 3/4/2025 | Chrome Android | 3/4/2025 | 0 | |
| html.elements.script.type.speculationrules 📋 | Chrome | 1/10/2023 | Chrome Android | 1/10/2023 | 0 | 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 | Chrome Android | 1/23/2024 | 0 | 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 | Chrome Android | 7/23/2024 | 0 | 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 Android | 6/21/2022 | Chrome | 2/7/2023 | 231 | |
| html.elements.script.type.speculationrules.prerender 📋 | Chrome Android | 6/21/2022 | Chrome | 9/2/2022 | 73 | |
| html.elements.script.type.speculationrules.referrer_policy 📋 | Chrome | 3/7/2023 | Chrome Android | 3/7/2023 | 0 | |
| html.elements.script.type.speculationrules.relative_to 📋 | Chrome | 1/23/2024 | Chrome Android | 1/23/2024 | 0 | |
| html.elements.script.type.speculationrules.requires 📋 | Chrome Android | 6/21/2022 | Chrome | 2/7/2023 | 231 | |
| html.elements.script.type.speculationrules.requires.anonymous-client-ip-when-cross-origin 📋 | Chrome Android | 6/21/2022 | Chrome | 2/7/2023 | 231 | |
| html.elements.script.type.speculationrules.source_optional 📋 | Chrome | 2/20/2024 | Chrome Android | 2/20/2024 | 0 | |
| html.elements.script.type.speculationrules.tag 📋 | Chrome | 4/29/2025 | Chrome Android | 4/29/2025 | 0 | |
| html.elements.script.type.speculationrules.target_hint 📋 | Chrome | 6/24/2025 | Chrome Android | 6/24/2025 | 0 | 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 Android | 6/21/2022 | Chrome | 1/10/2023 | 203 | |
| html.elements.script.type.speculationrules.where 📋 | Chrome | 1/23/2024 | Chrome Android | 1/23/2024 | 0 | |
| html.elements.selectedcontent 📋 | Chrome | 4/1/2025 | Chrome Android | 4/1/2025 | 0 | |
| html.elements.template.shadowrootreferencetarget | Chrome | 2/4/2025 | Chrome Android | 2/4/2025 | 0 | |
| html.elements.textarea.autocomplete.webauthn 📋 | Chrome | 11/29/2022 | Chrome Android | 11/29/2022 | 0 | |
| html.global_attributes.popover.hint 📋 | Chrome | 2/4/2025 | Chrome Android | 2/4/2025 | 0 | |
| html.global_attributes.virtualkeyboardpolicy 📋 | Chrome | 9/21/2021 | Chrome Android | 9/21/2021 | 0 |