Not yet stable

For a given set of browsers, what APIs are not yet in all of them.

Example Comparisons
Browsers
Features

Summary

A count of the number of APIs are in Browser X but not in Browser Y.
Not in ChromeNot in Safari
In Chrome 98
In Safari 8

Unstable APIs

Below is a list of features that are not in all of Chrome and Safari

Raw Data

Quick Links:

HTML Data

API First Browser Date Days in Limbo Notes
html.elements.a.attributionsourceid 📋Safari4/26/20211788
html.elements.a.attributionsrc 📋Chrome5/14/2024674
html.elements.a.hreftranslate Chrome4/7/20202172
html.elements.a.interestfor Chrome10/28/2025142
html.elements.a.referrerpolicy.no-referrer-when-downgrade Chrome5/25/20163585
html.elements.a.referrerpolicy.origin-when-cross-origin Chrome5/25/20163585
html.elements.a.referrerpolicy.unsafe-url Chrome5/25/20163585
html.elements.a.target.unfencedTop Chrome6/11/2024646
html.elements.area.attributionsrc 📋Chrome5/14/2024674
html.elements.area.interestfor Chrome10/28/2025142
html.elements.area.referrerpolicy.no-referrer-when-downgrade Chrome5/25/20163585
html.elements.area.referrerpolicy.origin-when-cross-origin Chrome5/25/20163585
html.elements.area.referrerpolicy.unsafe-url Chrome5/25/20163585
html.elements.audio.controlslist 📋Chrome4/19/20173256
html.elements.button.interestfor Chrome10/28/2025142
html.elements.dialog.closedby 📋Chrome3/4/2025380
html.elements.fencedframe 📋Chrome6/11/2024646
html.elements.fencedframe.allow 📋Chrome6/11/2024646
html.elements.fencedframe.height 📋Chrome6/11/2024646
html.elements.fencedframe.width 📋Chrome6/11/2024646
html.elements.geolocation 📋Chrome1/13/202665
html.elements.geolocation.autolocate 📋Chrome1/13/202665
html.elements.geolocation.watch 📋Chrome1/13/202665
html.elements.h1.no_ua_styles_in_article_aside_nav_section 📋Safari12/12/202597
html.elements.iframe.allow.accelerometer 📋Chrome4/17/20182893
html.elements.iframe.allow.ambient-light-sensor 📋Chrome4/17/20182893
html.elements.iframe.allow.attribution-reporting 📋Chrome9/12/2023919
html.elements.iframe.allow.autoplay 📋Chrome1/23/20182977
html.elements.iframe.allow.bluetooth 📋Chrome8/2/20221325
html.elements.iframe.allow.browsing-topics Chrome7/18/2023975
html.elements.iframe.allow.compute-pressure 📋Chrome5/14/2024674
html.elements.iframe.allow.cross-origin-isolated 📋Chrome11/17/20201948
html.elements.iframe.allow.document-domain 📋Chrome1/23/20182977
html.elements.iframe.allow.encrypted-media 📋Chrome1/23/20182977
html.elements.iframe.allow.fullscreen 📋Chrome10/17/20173075
html.elements.iframe.allow.geolocation 📋Chrome1/23/20182977
html.elements.iframe.allow.gyroscope 📋Chrome4/17/20182893
html.elements.iframe.allow.hid 📋Chrome3/2/20211843
html.elements.iframe.allow.identity-credentials-get 📋Chrome2/7/20231136
html.elements.iframe.allow.idle-detection 📋Chrome9/21/20211640
html.elements.iframe.allow.local-fonts 📋Chrome6/21/20221367
html.elements.iframe.allow.magnetometer 📋Chrome4/17/20182893
html.elements.iframe.allow.midi 📋Chrome1/23/20182977
html.elements.iframe.allow.otp-credentials 📋Chrome8/31/20211661
html.elements.iframe.allow.payment 📋Chrome7/25/20173159
html.elements.iframe.allow.picture-in-picture 📋Chrome9/4/20182753
html.elements.iframe.allow.publickey-credentials-get 📋Chrome7/27/20202061
html.elements.iframe.allow.serial 📋Chrome3/2/20211843
html.elements.iframe.allow.storage-access 📋Chrome5/2/20231052
html.elements.iframe.allow.usb 📋Chrome7/25/20173159
html.elements.iframe.allow.web-share 📋Chrome10/20/20201976
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.allow.wildcards Chrome11/29/20221206
html.elements.iframe.allow.window-management 📋Chrome3/29/20221451
html.elements.iframe.allow.xr-spatial-tracking 📋Chrome12/10/20192291
html.elements.iframe.allowpaymentrequest Chrome7/25/20173159
html.elements.iframe.browsingtopics Chrome6/11/2024646
html.elements.iframe.credentialless 📋Chrome2/7/20231136
html.elements.iframe.csp 📋Chrome9/5/20173117
html.elements.iframe.privateToken 📋Chrome9/12/2023919
html.elements.iframe.referrerpolicy.no-referrer-when-downgrade Chrome5/25/20163585
html.elements.iframe.referrerpolicy.origin-when-cross-origin Chrome5/25/20163585
html.elements.iframe.referrerpolicy.unsafe-url Chrome5/25/20163585
html.elements.iframe.sandbox.allow-orientation-lock 📋Chrome7/24/20182795
html.elements.iframe.sandbox.allow-presentation 📋Chrome8/31/20163487
html.elements.iframe.sandbox.allow-top-navigation-to-custom-protocols 📋Safari9/12/20221284
html.elements.img.attributionsrc 📋Chrome5/14/2024674
html.elements.img.referrerpolicy.no-referrer-when-downgrade Chrome5/25/20163585
html.elements.img.referrerpolicy.origin-when-cross-origin Chrome5/25/20163585
html.elements.img.referrerpolicy.unsafe-url Chrome5/25/20163585
html.elements.img.sizes.auto 📋Chrome6/11/2024646
html.elements.input.alpha 📋Safari3/31/2025353
html.elements.input.colorspace 📋Safari3/31/2025353
html.elements.input.switch Safari3/5/2024744
html.elements.input.type_color.accepts_css_colors 📋Safari3/31/2025353
html.elements.input.type_month 📋Chrome6/26/20125014
Safari: The input type is recognized, but there is no month-specific control. See bug 200416.
html.elements.input.type_range.labeled_values 📋Chrome10/7/20144181
html.elements.input.type_week 📋Chrome6/26/20125014
html.elements.link.referrerpolicy.no-referrer-when-downgrade Chrome5/25/20163585
html.elements.link.referrerpolicy.origin-when-cross-origin Chrome5/25/20163585
html.elements.link.referrerpolicy.unsafe-url Chrome5/25/20163585
html.elements.link.rel.compression-dictionary 📋Chrome10/15/2024520
html.elements.link.rel.expect 📋Chrome4/16/2024702
html.elements.link.rel.modulepreload.as-style 📋Chrome4/7/2026-19
html.elements.link.rel.prerender Chrome12/6/20173025
Chrome: Does not trigger prerendering. Triggers NoState Prefetch instead. See blog post.Chrome Android: Does not trigger prerendering. Triggers NoState Prefetch instead. See blog post.Edge: Does not trigger prerendering. Triggers NoState Prefetch instead. See blog post.Quest Browser: Does not trigger prerendering. Triggers NoState Prefetch instead. See blog post.Opera: Does not trigger prerendering. Triggers NoState Prefetch instead. See blog post.Opera Android: Does not trigger prerendering. Triggers NoState Prefetch instead. See blog post.WebView Android: Does not trigger prerendering. Triggers NoState Prefetch instead. See blog post.
html.elements.meta.name.application-title Chrome3/4/2025380
html.elements.script.attributionsrc 📋Chrome5/14/2024674
html.elements.script.referrerpolicy.no-referrer-when-downgrade Chrome10/16/20182711
html.elements.script.referrerpolicy.origin-when-cross-origin Chrome10/16/20182711
html.elements.script.referrerpolicy.unsafe-url Chrome10/16/20182711
html.elements.script.type.speculationrules.expects_no_vary_search 📋Chrome7/23/2024604
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.prerender 📋Chrome9/2/20221294
html.elements.script.type.speculationrules.requires 📋Chrome2/7/20231136
html.elements.script.type.speculationrules.requires.anonymous-client-ip-when-cross-origin 📋Chrome2/7/20231136
html.elements.script.type.speculationrules.target_hint 📋Chrome6/24/2025268
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.selectedcontent 📋Chrome4/1/2025352
html.elements.summary.display_list_item Chrome3/2/20211843
html.elements.td.rowspan.rowspan_zero Chrome3/6/20182935
html.elements.textarea.autocomplete.webauthn 📋Chrome11/29/20221206
html.elements.textarea.wrap.hard Chrome12/13/20115210
html.elements.video.controlslist 📋Chrome4/19/20173256
html.global_attributes.autocapitalize 📋Chrome5/19/20153957
html.global_attributes.autocorrect 📋Safari4/26/20211788
html.global_attributes.inert.ignores_find_in_page 📋Chrome4/16/2024702
html.global_attributes.is 📋Chrome5/29/20182851
html.global_attributes.popover.hint 📋Chrome2/4/2025408
html.global_attributes.virtualkeyboardpolicy 📋Chrome9/21/20211640