Experimental

For a given set of browsers what APIs are still considred experimental, and how long have they been experimental?

Example Comparisons
Browsers
Features

Summary

Experimental APIs

Below is a list of features that are marked as "Experimental" in Chrome and Chrome Android

Raw Data

Quick Links:

HTML Data

API First Browser Date Last Browser Date Days in experimentation Notes
html.elements.a.attributionsrc 📋Chrome5/14/2024 Chrome Android5/14/20240
html.elements.a.hreftranslate Chrome4/7/2020 Chrome Android4/7/20200
html.elements.a.target.unfencedTop Chrome7/18/2023 Chrome Android7/21/20233
html.elements.fencedframe 📋Chrome7/18/2023 Chrome Android7/21/20233
html.elements.fencedframe.allow 📋Chrome7/18/2023 Chrome Android7/21/20233
html.elements.fencedframe.height 📋Chrome7/18/2023 Chrome Android7/21/20233
html.elements.fencedframe.width 📋Chrome7/18/2023 Chrome Android7/21/20233
html.elements.form.autocomplete.webauthn 📋Chrome11/29/2022 Chrome Android11/29/20220
html.elements.iframe.allow.accelerometer 📋Chrome4/17/2018 Chrome Android4/17/20180
html.elements.iframe.allow.ambient-light-sensor 📋Chrome4/17/2018 Chrome Android4/17/20180
html.elements.iframe.allow.attribution-reporting 📋Chrome9/12/2023 Chrome Android9/12/20230
html.elements.iframe.allow.bluetooth 📋Chrome8/2/2022 Chrome Android8/2/20220
html.elements.iframe.allow.browsing-topics Chrome7/18/2023 Chrome Android7/21/20233
html.elements.iframe.allow.compute-pressure 📋Chrome5/14/2024 810
html.elements.iframe.allow.cross-origin-isolated 📋Chrome11/17/2020 Chrome Android11/17/20200
html.elements.iframe.allow.document-domain 📋Chrome1/23/2018 3113
html.elements.iframe.allow.gyroscope 📋Chrome4/17/2018 Chrome Android4/17/20180
html.elements.iframe.allow.hid 📋Chrome3/2/2021 Chrome Android3/2/20210
html.elements.iframe.allow.identity-credentials-get 📋Chrome2/7/2023 Chrome Android2/7/20230
html.elements.iframe.allow.idle-detection 📋Chrome9/21/2021 Chrome Android9/21/20210
html.elements.iframe.allow.local-fonts 📋Chrome6/21/2022 1503
html.elements.iframe.allow.magnetometer 📋Chrome4/17/2018 Chrome Android4/17/20180
html.elements.iframe.allow.otp-credentials 📋Chrome Android7/27/2020 Chrome8/31/2021400
html.elements.iframe.allow.picture-in-picture 📋Chrome12/4/2018 2798
html.elements.iframe.allow.serial 📋Chrome3/2/2021 Chrome Android3/2/20210
html.elements.iframe.allow.storage-access 📋Chrome5/2/2023 Chrome Android5/2/20230
html.elements.iframe.allow.usb 📋Chrome7/25/2017 Chrome Android8/1/20177
html.elements.iframe.allow.wildcards Chrome11/29/2022 Chrome Android11/29/20220
html.elements.iframe.allow.window-management 📋Chrome3/29/2022 Chrome Android3/29/20220
html.elements.iframe.allow.xr-spatial-tracking 📋Chrome12/10/2019 Chrome Android12/17/20197
html.elements.iframe.browsingtopics Chrome7/18/2023 Chrome Android7/21/20233
html.elements.iframe.credentialless 📋Chrome2/7/2023 Chrome Android2/7/20230
html.elements.iframe.csp 📋Chrome9/5/2017 Chrome Android9/5/20170
html.elements.img.attributionsrc 📋Chrome5/14/2024 Chrome Android5/14/20240
html.elements.link.rel.expect 📋Chrome4/16/2024 Chrome Android4/16/20240
html.elements.meta.name.application-title Chrome3/4/2025 Chrome Android3/4/20250
html.elements.script.attributionsrc 📋Chrome5/14/2024 Chrome Android5/14/20240
html.elements.script.type.importmap.multiple_import_maps 📋Chrome2/4/2025 Chrome Android2/4/20250
html.elements.script.type.speculationrules 📋Chrome1/10/2023 Chrome Android1/10/20230
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 Chrome1/23/2024 Chrome Android1/23/20240
html.elements.script.type.speculationrules.expects_no_vary_search Chrome7/23/2024 Chrome Android7/23/20240
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 Chrome Android6/21/2022 Chrome2/7/2023231
html.elements.script.type.speculationrules.prerender Chrome Android6/21/2022 Chrome9/2/202273
html.elements.script.type.speculationrules.referrer_policy Chrome3/7/2023 Chrome Android3/7/20230
html.elements.script.type.speculationrules.relative_to Chrome1/23/2024 Chrome Android1/23/20240
html.elements.script.type.speculationrules.requires Chrome Android6/21/2022 Chrome2/7/2023231
html.elements.script.type.speculationrules.requires.anonymous-client-ip-when-cross-origin Chrome Android6/21/2022 Chrome2/7/2023231
html.elements.script.type.speculationrules.source_optional Chrome2/20/2024 Chrome Android2/20/20240
html.elements.script.type.speculationrules.urls Chrome Android6/21/2022 Chrome1/10/2023203
html.elements.script.type.speculationrules.where Chrome1/23/2024 Chrome Android1/23/20240
html.elements.template.shadowrootserializable 📋Chrome5/14/2024 Chrome Android5/14/20240
html.elements.textarea.autocomplete.webauthn 📋Chrome11/29/2022 Chrome Android11/29/20220
html.global_attributes.hidden.until-found 📋Chrome5/24/2022 Chrome Android5/24/20220
html.global_attributes.virtualkeyboardpolicy 📋Chrome9/21/2021 Chrome Android9/21/20210
html.manifest.display_override 📋Chrome3/2/2021 Chrome Android3/2/20210
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 📋Chrome6/11/2024 Chrome Android6/11/20240
html.manifest.display_override.window-controls-overlay 📋Chrome9/2/2022 Chrome Android9/2/20220
html.manifest.file_handlers 📋Chrome5/24/2022 1531
html.manifest.launch_handler 📋Chrome2/7/2023 Chrome Android2/7/20230
html.manifest.launch_handler.client_mode 📋Chrome2/7/2023 Chrome Android2/7/20230
html.manifest.note_taking 📋Chrome10/19/2021 1748
html.manifest.note_taking.new_note_url 📋Chrome10/19/2021 1748
html.manifest.prefer_related_applications 📋Chrome Android7/29/2015 4022
Chrome: prefer_related_applications must be false or not present for a web app to be installable.Edge: prefer_related_applications must be false or not present for a web app to be installable.Firefox for Android: The property parses, but has no effect.Opera: prefer_related_applications must be false or not present for a web app to be installable.
html.manifest.protocol_handlers 📋Chrome11/15/2021 Chrome Android11/15/20210
html.manifest.protocol_handlers.protocol 📋Chrome11/15/2021 Chrome Android11/15/20210
html.manifest.protocol_handlers.url 📋Chrome11/15/2021 Chrome Android11/15/20210
html.manifest.related_applications 📋Chrome Android7/29/2015 4022
Firefox for Android: The property parses, but has no effect.
html.manifest.serviceworker Chrome10/16/2018 Chrome Android10/17/20181
html.manifest.serviceworker.scope Chrome10/16/2018 Chrome Android10/17/20181
html.manifest.serviceworker.src Chrome10/16/2018 Chrome Android10/17/20181
html.manifest.serviceworker.use_cache Chrome10/16/2018 Chrome Android10/17/20181
html.manifest.share_target 📋Chrome Android7/30/2019 Chrome3/2/2021581
Firefox for Android: The property parses, but has no effect.