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 Firefox and Chrome Android

Raw Data

Quick Links:

CSS Data

API First Browser Date Last Browser Date Days in experimentation Notes
css.at-rules.container.anchor_position_queries 📋Chrome Android12/2/2025 230
css.at-rules.container.anchor_position_queries.fallback 📋Chrome Android12/2/2025 230
css.at-rules.container.anchor_position_queries.fallback.any_value 📋Chrome Android12/2/2025 230
css.at-rules.container.scroll-state_queries 📋Chrome Android2/4/2025 531
css.at-rules.container.scroll-state_queries.scrollable 📋Chrome Android2/4/2025 531
css.at-rules.container.scroll-state_queries.scrolled 📋Chrome Android1/13/2026 188
css.at-rules.container.scroll-state_queries.snapped 📋Chrome Android2/4/2025 531
css.at-rules.container.scroll-state_queries.stuck 📋Chrome Android2/4/2025 531
css.at-rules.container.style_queries_for_custom_properties.range_syntax 📋Chrome Android10/28/2025 265
css.at-rules.custom-media 📋Firefox2/24/2026 146
css.at-rules.function 📋Chrome Android8/5/2025 349
css.at-rules.function.result 📋Chrome Android8/5/2025 349
css.at-rules.media.device-posture 📋Chrome Android1/14/2025 552
css.at-rules.media.horizontal-viewport-segments 📋Chrome Android6/24/2025 391
css.at-rules.media.prefers-reduced-data 📋Chrome Android8/25/2020 2155
css.at-rules.media.prefers-reduced-transparency 📋Firefox5/9/2023 Chrome Android10/10/2023154
css.at-rules.media.vertical-viewport-segments 📋Chrome Android6/24/2025 391
css.at-rules.page.bottom-center 📋Chrome Android11/12/2024 615
css.at-rules.page.bottom-left 📋Chrome Android11/12/2024 615
css.at-rules.page.bottom-left-corner 📋Chrome Android11/12/2024 615
css.at-rules.page.bottom-right 📋Chrome Android11/12/2024 615
css.at-rules.page.bottom-right-corner 📋Chrome Android11/12/2024 615
css.at-rules.page.left-bottom 📋Chrome Android11/12/2024 615
css.at-rules.page.left-middle 📋Chrome Android11/12/2024 615
css.at-rules.page.left-top 📋Chrome Android11/12/2024 615
css.at-rules.page.right-bottom 📋Chrome Android11/12/2024 615
css.at-rules.page.right-middle 📋Chrome Android11/12/2024 615
css.at-rules.page.right-top 📋Chrome Android11/12/2024 615
css.at-rules.page.top-center 📋Chrome Android11/12/2024 615
css.at-rules.page.top-left 📋Chrome Android11/12/2024 615
css.at-rules.page.top-left-corner 📋Chrome Android11/12/2024 615
css.at-rules.page.top-right 📋Chrome Android11/12/2024 615
css.at-rules.page.top-right-corner 📋Chrome Android11/12/2024 615
css.properties.-webkit-app-region Chrome Android2/27/2013 4891
css.properties.animation-trigger 📋Chrome Android3/10/2026 132
css.properties.animation-trigger.none 📋Chrome Android3/10/2026 132
css.properties.appearance.base-select 📋Chrome Android4/1/2025 475
css.properties.background-image.element 📋Firefox3/22/2011 5599
css.properties.block-size.fit-content_function Firefox8/10/2021 1805
css.properties.block-size.stretch 📋Chrome Android6/24/2025 391
css.properties.break-after.always Firefox1/29/2019 2729
css.properties.break-before.always Firefox1/29/2019 2729
css.properties.caret-animation 📋Chrome Android9/2/2025 321
css.properties.caret-animation.auto 📋Chrome Android9/2/2025 321
css.properties.caret-animation.manual 📋Chrome Android9/2/2025 321
css.properties.caret-shape 📋Chrome Android1/13/2026 188
css.properties.caret-shape.auto 📋Chrome Android1/13/2026 188
css.properties.caret-shape.bar 📋Chrome Android1/13/2026 188
css.properties.caret-shape.block 📋Chrome Android1/13/2026 188
css.properties.caret-shape.underscore 📋Chrome Android1/13/2026 188
css.properties.column-height 📋Chrome Android2/10/2026 160
css.properties.column-height.auto 📋Chrome Android2/10/2026 160
css.properties.column-wrap 📋Chrome Android2/10/2026 160
css.properties.column-wrap.auto 📋Chrome Android2/10/2026 160
css.properties.column-wrap.nowrap 📋Chrome Android2/10/2026 160
css.properties.column-wrap.wrap 📋Chrome Android2/10/2026 160
css.properties.columns.column-height 📋Chrome Android2/10/2026 160
css.properties.container-type.anchored 📋Chrome Android12/2/2025 230
css.properties.container-type.scroll-state 📋Chrome Android2/4/2025 531
css.properties.content.alt_text.counters Chrome Android9/2/2025 321
Chrome: Counters are recognised, but the spoken values do not incrementChrome Android: Counters are recognised, but the spoken values do not incrementEdge: Counters are recognised, but the spoken values do not incrementOpera: Counters are recognised, but the spoken values do not incrementOpera Android: Counters are recognised, but the spoken values do not incrementWebView Android: Counters are recognised, but the spoken values do not increment
css.properties.content.none_applies_to_elements Firefox8/10/2021 1805
css.properties.corner-block-end-shape 📋Chrome Android8/5/2025 349
css.properties.corner-block-end-shape.bevel 📋Chrome Android8/5/2025 349
css.properties.corner-block-end-shape.notch 📋Chrome Android8/5/2025 349
css.properties.corner-block-end-shape.round 📋Chrome Android8/5/2025 349
css.properties.corner-block-end-shape.scoop 📋Chrome Android8/5/2025 349
css.properties.corner-block-end-shape.square 📋Chrome Android8/5/2025 349
css.properties.corner-block-end-shape.squircle 📋Chrome Android8/5/2025 349
css.properties.corner-block-start-shape 📋Chrome Android8/5/2025 349
css.properties.corner-block-start-shape.bevel 📋Chrome Android8/5/2025 349
css.properties.corner-block-start-shape.notch 📋Chrome Android8/5/2025 349
css.properties.corner-block-start-shape.round 📋Chrome Android8/5/2025 349
css.properties.corner-block-start-shape.scoop 📋Chrome Android8/5/2025 349
css.properties.corner-block-start-shape.square 📋Chrome Android8/5/2025 349
css.properties.corner-block-start-shape.squircle 📋Chrome Android8/5/2025 349
css.properties.corner-bottom-left-shape 📋Chrome Android8/5/2025 349
css.properties.corner-bottom-left-shape.bevel 📋Chrome Android8/5/2025 349
css.properties.corner-bottom-left-shape.notch 📋Chrome Android8/5/2025 349
css.properties.corner-bottom-left-shape.round 📋Chrome Android8/5/2025 349
css.properties.corner-bottom-left-shape.scoop 📋Chrome Android8/5/2025 349
css.properties.corner-bottom-left-shape.square 📋Chrome Android8/5/2025 349
css.properties.corner-bottom-left-shape.squircle 📋Chrome Android8/5/2025 349
css.properties.corner-bottom-right-shape 📋Chrome Android8/5/2025 349
css.properties.corner-bottom-right-shape.bevel 📋Chrome Android8/5/2025 349
css.properties.corner-bottom-right-shape.notch 📋Chrome Android8/5/2025 349
css.properties.corner-bottom-right-shape.round 📋Chrome Android8/5/2025 349
css.properties.corner-bottom-right-shape.scoop 📋Chrome Android8/5/2025 349
css.properties.corner-bottom-right-shape.square 📋Chrome Android8/5/2025 349
css.properties.corner-bottom-right-shape.squircle 📋Chrome Android8/5/2025 349
css.properties.corner-bottom-shape 📋Chrome Android8/5/2025 349
css.properties.corner-bottom-shape.bevel 📋Chrome Android8/5/2025 349
css.properties.corner-bottom-shape.notch 📋Chrome Android8/5/2025 349
css.properties.corner-bottom-shape.round 📋Chrome Android8/5/2025 349
css.properties.corner-bottom-shape.scoop 📋Chrome Android8/5/2025 349
css.properties.corner-bottom-shape.square 📋Chrome Android8/5/2025 349
css.properties.corner-bottom-shape.squircle 📋Chrome Android8/5/2025 349
css.properties.corner-end-end-shape 📋Chrome Android8/5/2025 349
css.properties.corner-end-end-shape.bevel 📋Chrome Android8/5/2025 349
css.properties.corner-end-end-shape.notch 📋Chrome Android8/5/2025 349
css.properties.corner-end-end-shape.round 📋Chrome Android8/5/2025 349
css.properties.corner-end-end-shape.scoop 📋Chrome Android8/5/2025 349
css.properties.corner-end-end-shape.square 📋Chrome Android8/5/2025 349
css.properties.corner-end-end-shape.squircle 📋Chrome Android8/5/2025 349
css.properties.corner-end-start-shape 📋Chrome Android8/5/2025 349
css.properties.corner-end-start-shape.bevel 📋Chrome Android8/5/2025 349
css.properties.corner-end-start-shape.notch 📋Chrome Android8/5/2025 349
css.properties.corner-end-start-shape.round 📋Chrome Android8/5/2025 349
css.properties.corner-end-start-shape.scoop 📋Chrome Android8/5/2025 349
css.properties.corner-end-start-shape.square 📋Chrome Android8/5/2025 349
css.properties.corner-end-start-shape.squircle 📋Chrome Android8/5/2025 349
css.properties.corner-inline-end-shape 📋Chrome Android8/5/2025 349
css.properties.corner-inline-end-shape.bevel 📋Chrome Android8/5/2025 349
css.properties.corner-inline-end-shape.notch 📋Chrome Android8/5/2025 349
css.properties.corner-inline-end-shape.round 📋Chrome Android8/5/2025 349
css.properties.corner-inline-end-shape.scoop 📋Chrome Android8/5/2025 349
css.properties.corner-inline-end-shape.square 📋Chrome Android8/5/2025 349
css.properties.corner-inline-end-shape.squircle 📋Chrome Android8/5/2025 349
css.properties.corner-inline-start-shape 📋Chrome Android8/5/2025 349
css.properties.corner-inline-start-shape.bevel 📋Chrome Android8/5/2025 349
css.properties.corner-inline-start-shape.notch 📋Chrome Android8/5/2025 349
css.properties.corner-inline-start-shape.round 📋Chrome Android8/5/2025 349
css.properties.corner-inline-start-shape.scoop 📋Chrome Android8/5/2025 349
css.properties.corner-inline-start-shape.square 📋Chrome Android8/5/2025 349
css.properties.corner-inline-start-shape.squircle 📋Chrome Android8/5/2025 349
css.properties.corner-left-shape 📋Chrome Android8/5/2025 349
css.properties.corner-left-shape.bevel 📋Chrome Android8/5/2025 349
css.properties.corner-left-shape.notch 📋Chrome Android8/5/2025 349
css.properties.corner-left-shape.round 📋Chrome Android8/5/2025 349
css.properties.corner-left-shape.scoop 📋Chrome Android8/5/2025 349
css.properties.corner-left-shape.square 📋Chrome Android8/5/2025 349
css.properties.corner-left-shape.squircle 📋Chrome Android8/5/2025 349
css.properties.corner-right-shape 📋Chrome Android8/5/2025 349
css.properties.corner-right-shape.bevel 📋Chrome Android8/5/2025 349
css.properties.corner-right-shape.notch 📋Chrome Android8/5/2025 349
css.properties.corner-right-shape.round 📋Chrome Android8/5/2025 349
css.properties.corner-right-shape.scoop 📋Chrome Android8/5/2025 349
css.properties.corner-right-shape.square 📋Chrome Android8/5/2025 349
css.properties.corner-right-shape.squircle 📋Chrome Android8/5/2025 349
css.properties.corner-shape 📋Chrome Android8/5/2025 349
css.properties.corner-shape.bevel 📋Chrome Android8/5/2025 349
css.properties.corner-shape.notch 📋Chrome Android8/5/2025 349
css.properties.corner-shape.round 📋Chrome Android8/5/2025 349
css.properties.corner-shape.scoop 📋Chrome Android8/5/2025 349
css.properties.corner-shape.square 📋Chrome Android8/5/2025 349
css.properties.corner-shape.squircle 📋Chrome Android8/5/2025 349
css.properties.corner-start-end-shape 📋Chrome Android8/5/2025 349
css.properties.corner-start-end-shape.bevel 📋Chrome Android8/5/2025 349
css.properties.corner-start-end-shape.notch 📋Chrome Android8/5/2025 349
css.properties.corner-start-end-shape.round 📋Chrome Android8/5/2025 349
css.properties.corner-start-end-shape.scoop 📋Chrome Android8/5/2025 349
css.properties.corner-start-end-shape.square 📋Chrome Android8/5/2025 349
css.properties.corner-start-end-shape.squircle 📋Chrome Android8/5/2025 349
css.properties.corner-start-start-shape 📋Chrome Android8/5/2025 349
css.properties.corner-start-start-shape.bevel 📋Chrome Android8/5/2025 349
css.properties.corner-start-start-shape.notch 📋Chrome Android8/5/2025 349
css.properties.corner-start-start-shape.round 📋Chrome Android8/5/2025 349
css.properties.corner-start-start-shape.scoop 📋Chrome Android8/5/2025 349
css.properties.corner-start-start-shape.square 📋Chrome Android8/5/2025 349
css.properties.corner-start-start-shape.squircle 📋Chrome Android8/5/2025 349
css.properties.corner-top-left-shape 📋Chrome Android8/5/2025 349
css.properties.corner-top-left-shape.bevel 📋Chrome Android8/5/2025 349
css.properties.corner-top-left-shape.notch 📋Chrome Android8/5/2025 349
css.properties.corner-top-left-shape.round 📋Chrome Android8/5/2025 349
css.properties.corner-top-left-shape.scoop 📋Chrome Android8/5/2025 349
css.properties.corner-top-left-shape.square 📋Chrome Android8/5/2025 349
css.properties.corner-top-left-shape.squircle 📋Chrome Android8/5/2025 349
css.properties.corner-top-right-shape 📋Chrome Android8/5/2025 349
css.properties.corner-top-right-shape.bevel 📋Chrome Android8/5/2025 349
css.properties.corner-top-right-shape.notch 📋Chrome Android8/5/2025 349
css.properties.corner-top-right-shape.round 📋Chrome Android8/5/2025 349
css.properties.corner-top-right-shape.scoop 📋Chrome Android8/5/2025 349
css.properties.corner-top-right-shape.square 📋Chrome Android8/5/2025 349
css.properties.corner-top-right-shape.squircle 📋Chrome Android8/5/2025 349
css.properties.corner-top-shape 📋Chrome Android8/5/2025 349
css.properties.corner-top-shape.bevel 📋Chrome Android8/5/2025 349
css.properties.corner-top-shape.notch 📋Chrome Android8/5/2025 349
css.properties.corner-top-shape.round 📋Chrome Android8/5/2025 349
css.properties.corner-top-shape.scoop 📋Chrome Android8/5/2025 349
css.properties.corner-top-shape.square 📋Chrome Android8/5/2025 349
css.properties.corner-top-shape.squircle 📋Chrome Android8/5/2025 349
css.properties.counter-reset.reset_does_not_affect_siblings Firefox10/20/2020 2099
css.properties.counter-reset.reversed 📋Firefox1/11/2022 1651
css.properties.display.math Chrome Android1/10/2023 1287
css.properties.dynamic-range-limit.constrained 📋Chrome Android4/29/2025 447
css.properties.dynamic-range-limit.dynamic-range-limit-mix_values 📋Chrome Android4/29/2025 447
css.properties.flex.stretch 📋Chrome Android6/24/2025 391
css.properties.flex-basis.stretch 📋Chrome Android6/24/2025 391
css.properties.font-palette.animation_computed Chrome Android1/23/2024 909
css.properties.font-palette.palette-mix_function 📋Chrome Android1/23/2024 909
css.properties.font-synthesis-position 📋Firefox9/26/2023 1028
css.properties.font-synthesis-position.auto 📋Firefox9/26/2023 1028
css.properties.font-synthesis-position.none 📋Firefox9/26/2023 1028
css.properties.font-synthesis-style.oblique-only 📋Firefox4/1/2025 475
css.properties.forced-color-adjust.preserve-parent-color 📋Chrome Android9/27/2022 1392
css.properties.grid-template-columns.masonry 📋Firefox6/2/2020 2239
css.properties.grid-template-rows.masonry 📋Firefox6/2/2020 2239
css.properties.height.fit-content_function 📋Firefox8/10/2021 1805
css.properties.image-rendering.smooth 📋Firefox10/5/2021 1749
css.properties.inline-size.fit-content_function Firefox8/10/2021 1805
css.properties.inline-size.stretch 📋Chrome Android6/24/2025 391
css.properties.interactivity 📋Chrome Android4/1/2025 475
css.properties.interactivity.auto 📋Chrome Android4/1/2025 475
css.properties.interactivity.inert 📋Chrome Android4/1/2025 475
css.properties.interest-delay 📋Chrome Android10/28/2025 265
css.properties.interest-delay.normal 📋Chrome Android10/28/2025 265
css.properties.interest-delay-end 📋Chrome Android10/28/2025 265
css.properties.interest-delay-end.normal 📋Chrome Android10/28/2025 265
css.properties.interest-delay-start 📋Chrome Android10/28/2025 265
css.properties.interest-delay-start.normal 📋Chrome Android10/28/2025 265
css.properties.interpolate-size 📋Chrome Android9/17/2024 671
css.properties.interpolate-size.allow-keywords 📋Chrome Android9/17/2024 671
css.properties.interpolate-size.numeric-only 📋Chrome Android9/17/2024 671
css.properties.justify-items.block_context 📋Chrome Android10/15/2024 643
css.properties.justify-self.block_context 📋Chrome Android10/15/2024 643
css.properties.max-block-size.fit-content_function Firefox8/10/2021 1805
css.properties.max-block-size.stretch 📋Chrome Android6/24/2025 391
css.properties.max-height.fit-content_function 📋Firefox8/10/2021 1805
css.properties.max-inline-size.fit-content_function Firefox8/10/2021 1805
css.properties.max-inline-size.stretch 📋Chrome Android6/24/2025 391
css.properties.max-width.fit-content_function 📋Firefox8/10/2021 1805
css.properties.min-block-size.fit-content_function Firefox8/10/2021 1805
css.properties.min-block-size.stretch 📋Chrome Android6/24/2025 391
css.properties.min-height.fit-content_function 📋Firefox8/10/2021 1805
css.properties.min-inline-size.fit-content_function Firefox8/10/2021 1805
css.properties.min-inline-size.stretch 📋Chrome Android6/24/2025 391
css.properties.min-width.fit-content_function 📋Firefox8/10/2021 1805
css.properties.object-view-box 📋Chrome Android8/2/2022 1448
css.properties.object-view-box.none 📋Chrome Android8/2/2022 1448
css.properties.overlay 📋Chrome Android9/12/2023 1042
css.properties.overlay.auto 📋Chrome Android9/12/2023 1042
css.properties.overlay.none 📋Chrome Android9/12/2023 1042
css.properties.reading-flow 📋Chrome Android5/27/2025 419
css.properties.reading-flow.flex-flow 📋Chrome Android5/27/2025 419
css.properties.reading-flow.flex-visual 📋Chrome Android5/27/2025 419
css.properties.reading-flow.grid-columns 📋Chrome Android5/27/2025 419
css.properties.reading-flow.grid-order 📋Chrome Android5/27/2025 419
css.properties.reading-flow.grid-rows 📋Chrome Android5/27/2025 419
css.properties.reading-flow.normal 📋Chrome Android5/27/2025 419
css.properties.reading-flow.source-order 📋Chrome Android5/27/2025 419
css.properties.reading-order 📋Chrome Android5/27/2025 419
css.properties.ruby-position.alternate Firefox4/19/2021 1918
css.properties.scroll-initial-target 📋Chrome Android2/4/2025 531
css.properties.scroll-initial-target.nearest 📋Chrome Android2/4/2025 531
css.properties.scroll-initial-target.none 📋Chrome Android2/4/2025 531
css.properties.scroll-marker-group 📋Chrome Android4/1/2025 475
css.properties.scroll-marker-group.after 📋Chrome Android4/1/2025 475
css.properties.scroll-marker-group.before 📋Chrome Android4/1/2025 475
css.properties.scroll-marker-group.none 📋Chrome Android4/1/2025 475
css.properties.scroll-target-group 📋Chrome Android9/2/2025 321
css.properties.scroll-target-group.auto 📋Chrome Android9/2/2025 321
css.properties.scroll-target-group.none 📋Chrome Android9/2/2025 321
css.properties.text-autospace.insert 📋Firefox11/11/2025 251
css.properties.text-decoration-inset 📋Firefox12/9/2025 223
css.properties.text-decoration-inset.auto 📋Firefox12/9/2025 223
css.properties.text-emphasis-position.auto Firefox10/29/2024 629
css.properties.text-size-adjust 📋Chrome Android10/19/2016 3561
css.properties.text-size-adjust.auto 📋Chrome Android10/19/2016 3561
css.properties.text-size-adjust.none 📋Chrome Android10/19/2016 3561
css.properties.text-size-adjust.percentages 📋Chrome Android10/19/2016 3561
css.properties.text-spacing-trim 📋Chrome Android3/19/2024 853
css.properties.text-spacing-trim.normal 📋Chrome Android3/19/2024 853
css.properties.text-spacing-trim.space-all 📋Chrome Android3/19/2024 853
css.properties.text-spacing-trim.space-first 📋Chrome Android3/19/2024 853
css.properties.text-spacing-trim.trim-start 📋Chrome Android3/19/2024 853
css.properties.timeline-trigger 📋Chrome Android3/10/2026 132
css.properties.timeline-trigger.auto 📋Chrome Android3/10/2026 132
css.properties.timeline-trigger.none 📋Chrome Android3/10/2026 132
css.properties.timeline-trigger.normal 📋Chrome Android3/10/2026 132
css.properties.timeline-trigger-name 📋Chrome Android3/10/2026 132
css.properties.timeline-trigger-name.none 📋Chrome Android3/10/2026 132
css.properties.timeline-trigger-source 📋Chrome Android3/10/2026 132
css.properties.timeline-trigger-source.auto 📋Chrome Android3/10/2026 132
css.properties.timeline-trigger-source.none 📋Chrome Android3/10/2026 132
css.properties.trigger-scope 📋Chrome Android3/10/2026 132
css.properties.trigger-scope.all 📋Chrome Android3/10/2026 132
css.properties.trigger-scope.none 📋Chrome Android3/10/2026 132
css.properties.view-transition-group 📋Chrome Android9/2/2025 321
css.properties.view-transition-group.contain Chrome Android9/2/2025 321
css.properties.view-transition-group.nearest Chrome Android9/2/2025 321
css.properties.view-transition-group.normal Chrome Android9/2/2025 321
css.properties.white-space.preserve-spaces 📋Firefox3/19/2024 853
css.properties.white-space-collapse.preserve-spaces 📋Firefox3/19/2024 853
css.properties.width.fit-content_function 📋Firefox8/10/2021 1805
css.properties.word-break.auto-phrase 📋Chrome Android10/31/2023 993
Chrome: This value is only applicable if lang="ja" is specified. This value has no effect on other locales.Chrome Android: This value is only applicable if lang="ja" is specified. This value has no effect on other locales.Edge: This value is only applicable if lang="ja" is specified. This value has no effect on other locales.Opera: This value is only applicable if lang="ja" is specified. This value has no effect on other locales.Opera Android: This value is only applicable if lang="ja" is specified. This value has no effect on other locales.Samsung Internet: This value is only applicable if lang="ja" is specified. This value has no effect on other locales.WebView Android: This value is only applicable if lang="ja" is specified. This value has no effect on other locales.
css.selectors.-moz-first-node Firefox8/8/2017 3268
css.selectors.-moz-last-node Firefox8/8/2017 3268
css.selectors.-moz-list-bullet Firefox11/9/2004 7923
css.selectors.-moz-list-number Firefox11/9/2004 7923
css.selectors.-moz-progress-bar Firefox8/16/2011 5452
css.selectors.checkmark 📋Chrome Android2/4/2025 531
css.selectors.column 📋Chrome Android4/1/2025 475
css.selectors.column.nested_scroll-marker Chrome Android4/1/2025 475
css.selectors.interest-source 📋Chrome Android10/28/2025 265
css.selectors.interest-target 📋Chrome Android10/28/2025 265
css.selectors.marker.counter_support 📋Firefox1/13/2026 188
css.selectors.marker.quotes_support 📋Firefox1/13/2026 188
css.selectors.picker 📋Chrome Android4/1/2025 475
css.selectors.picker-icon 📋Chrome Android2/4/2025 531
css.selectors.scroll-button 📋Chrome Android4/1/2025 475
css.selectors.scroll-button.block-end 📋Chrome Android4/1/2025 475
css.selectors.scroll-button.block-start 📋Chrome Android4/1/2025 475
css.selectors.scroll-button.down 📋Chrome Android4/1/2025 475
css.selectors.scroll-button.inline-end 📋Chrome Android4/1/2025 475
css.selectors.scroll-button.inline-start 📋Chrome Android4/1/2025 475
css.selectors.scroll-button.left 📋Chrome Android4/1/2025 475
css.selectors.scroll-button.right 📋Chrome Android4/1/2025 475
css.selectors.scroll-button.star 📋Chrome Android4/1/2025 475
css.selectors.scroll-button.up 📋Chrome Android4/1/2025 475
css.selectors.scroll-marker 📋Chrome Android4/1/2025 475
css.selectors.scroll-marker-group 📋Chrome Android4/1/2025 475
css.selectors.search-text 📋Chrome Android1/13/2026 188
css.selectors.target-after 📋Chrome Android10/28/2025 265
css.selectors.target-before 📋Chrome Android10/28/2025 265
css.selectors.target-current 📋Chrome Android4/1/2025 475
css.selectors.view-transition-group-children 📋Chrome Android9/2/2025 321
css.selectors.xr-overlay 📋Chrome Android5/19/2020 2253
css.types.attr.type_function 📋Chrome Android2/4/2025 531
css.types.attr.type_function.angle 📋Chrome Android2/4/2025 531
css.types.attr.type_function.color 📋Chrome Android2/4/2025 531
css.types.attr.type_function.custom-ident 📋Chrome Android2/4/2025 531
css.types.attr.type_function.ident 📋Chrome Android2/4/2025 531
css.types.attr.type_function.image 📋Chrome Android2/4/2025 531
css.types.attr.type_function.integer 📋Chrome Android2/4/2025 531
css.types.attr.type_function.length 📋Chrome Android2/4/2025 531
css.types.attr.type_function.length-percentage 📋Chrome Android2/4/2025 531
css.types.attr.type_function.number 📋Chrome Android2/4/2025 531
css.types.attr.type_function.percentage 📋Chrome Android2/4/2025 531
css.types.attr.type_function.resolution 📋Chrome Android2/4/2025 531
css.types.attr.type_function.string 📋Chrome Android2/4/2025 531
css.types.attr.type_function.time 📋Chrome Android2/4/2025 531
css.types.attr.type_function.transform-function 📋Chrome Android2/4/2025 531
css.types.attr.type_function.url 📋Chrome Android2/4/2025 531
css.types.calc-size 📋Chrome Android9/17/2024 671
css.types.corner-shape-value 📋Chrome Android8/5/2025 349
css.types.corner-shape-value.bevel 📋Chrome Android8/5/2025 349
css.types.corner-shape-value.notch 📋Chrome Android8/5/2025 349
css.types.corner-shape-value.round 📋Chrome Android8/5/2025 349
css.types.corner-shape-value.scoop 📋Chrome Android8/5/2025 349
css.types.corner-shape-value.square 📋Chrome Android8/5/2025 349
css.types.corner-shape-value.squircle 📋Chrome Android8/5/2025 349
css.types.corner-shape-value.superellipse 📋Chrome Android8/5/2025 349
css.types.dashed-function 📋Chrome Android8/5/2025 349
css.types.dynamic-range-limit-mix 📋Chrome Android4/29/2025 447
css.types.env.keyboard-inset-bottom 📋Chrome Android9/21/2021 1763
css.types.env.keyboard-inset-height 📋Chrome Android9/21/2021 1763
css.types.env.keyboard-inset-left 📋Chrome Android9/21/2021 1763
css.types.env.keyboard-inset-right 📋Chrome Android9/21/2021 1763
css.types.env.keyboard-inset-top 📋Chrome Android9/21/2021 1763
css.types.env.keyboard-inset-width 📋Chrome Android9/21/2021 1763
css.types.env.viewport-segment-bottom 📋Chrome Android6/24/2025 391
css.types.env.viewport-segment-height 📋Chrome Android6/24/2025 391
css.types.env.viewport-segment-left 📋Chrome Android6/24/2025 391
css.types.env.viewport-segment-right 📋Chrome Android6/24/2025 391
css.types.env.viewport-segment-top 📋Chrome Android6/24/2025 391
css.types.env.viewport-segment-width 📋Chrome Android6/24/2025 391
css.types.if 📋Chrome Android5/27/2025 419
css.types.if.style Chrome Android5/27/2025 419
css.types.if.style.range_syntax 📋Chrome Android10/28/2025 265
css.types.image.element 📋Firefox11/14/2017 3170
Firefox: -moz-element() is limited to background-image, background, border-image and border-image-source.Firefox: -moz-element() is limited to background-image and background.Firefox for Android: -moz-element() is limited to background-image, background, border-image and border-image-source.Firefox for Android: -moz-element() is limited to background-image and background.
css.types.ratio.number_value Firefox6/30/2020 2211
css.types.superellipse 📋Chrome Android8/5/2025 349
css.types.type 📋Chrome Android8/5/2025 349

HTML Data

API First Browser Date Last Browser Date Days in experimentation Notes
html.elements.a.hreftranslate Chrome Android4/7/2020 2295
html.elements.a.interestfor Chrome Android10/28/2025 265
html.elements.a.target.unfencedTop Chrome Android6/11/2024 769
html.elements.area.interestfor Chrome Android10/28/2025 265
html.elements.button.interestfor Chrome Android10/28/2025 265
html.elements.fencedframe 📋Chrome Android6/11/2024 769
html.elements.fencedframe.allow 📋Chrome Android6/11/2024 769
html.elements.fencedframe.height 📋Chrome Android6/11/2024 769
html.elements.fencedframe.width 📋Chrome Android6/11/2024 769
html.elements.geolocation 📋Chrome Android1/13/2026 188
html.elements.geolocation.autolocate 📋Chrome Android1/13/2026 188
html.elements.geolocation.watch 📋Chrome Android1/13/2026 188
html.elements.iframe.allow.accelerometer 📋Chrome Android4/17/2018 3016
html.elements.iframe.allow.ambient-light-sensor 📋Chrome Android4/17/2018 3016
html.elements.iframe.allow.bluetooth 📋Chrome Android8/2/2022 1448
html.elements.iframe.allow.cross-origin-isolated 📋Chrome Android11/17/2020 2071
html.elements.iframe.allow.document-domain 📋Firefox3/10/2020 2323
html.elements.iframe.allow.gamepad 📋Firefox8/10/2021 1805
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 📋Chrome Android4/17/2018 3016
html.elements.iframe.allow.hid 📋Chrome Android3/2/2021 1966
html.elements.iframe.allow.identity-credentials-get 📋Chrome Android2/7/2023 1259
html.elements.iframe.allow.idle-detection 📋Chrome Android9/21/2021 1763
html.elements.iframe.allow.magnetometer 📋Chrome Android4/17/2018 3016
html.elements.iframe.allow.otp-credentials 📋Chrome Android7/27/2020 2184
html.elements.iframe.allow.picture-in-picture 📋Chrome Android9/2/2022 1417
html.elements.iframe.allow.serial 📋Chrome Android3/2/2021 1966
html.elements.iframe.allow.speaker-selection 📋Firefox8/1/2023 1084
Firefox for Android: Not available due to a limitation in Android (see bug 1473346).
html.elements.iframe.allow.storage-access 📋Chrome Android5/2/2023 1175
html.elements.iframe.allow.usb 📋Chrome Android8/1/2017 3275
html.elements.iframe.allow.wildcards Chrome Android11/29/2022 1329
html.elements.iframe.allow.window-management 📋Chrome Android3/29/2022 1574
html.elements.iframe.allow.xr-spatial-tracking 📋Chrome Android12/17/2019 2407
html.elements.iframe.credentialless 📋Chrome Android2/7/2023 1259
html.elements.iframe.csp 📋Chrome Android9/5/2017 3240
html.elements.iframe.privateToken 📋Chrome Android9/12/2023 1042
html.elements.link.rel.compression-dictionary 📋Chrome Android10/15/2024 643
html.elements.link.rel.expect 📋Chrome Android4/16/2024 825
html.elements.link.rel.modulepreload.as-style 📋Chrome Android4/7/2026 104
html.elements.meta.name.application-title Chrome Android3/4/2025 503
html.elements.script.type.speculationrules 📋Chrome Android1/10/2023 1287
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 Android1/23/2024 909
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 Android7/23/2024 727
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 Android6/21/2022 1490
html.elements.script.type.speculationrules.prerender 📋Chrome Android6/21/2022 1490
html.elements.script.type.speculationrules.referrer_policy 📋Chrome Android3/7/2023 1231
html.elements.script.type.speculationrules.relative_to 📋Chrome Android1/23/2024 909
html.elements.script.type.speculationrules.requires 📋Chrome Android6/21/2022 1490
html.elements.script.type.speculationrules.requires.anonymous-client-ip-when-cross-origin 📋Chrome Android6/21/2022 1490
html.elements.script.type.speculationrules.source_optional 📋Chrome Android2/20/2024 881
html.elements.script.type.speculationrules.tag 📋Chrome Android4/29/2025 447
html.elements.script.type.speculationrules.target_hint 📋Chrome Android6/24/2025 391
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 Android6/21/2022 1490
html.elements.script.type.speculationrules.where 📋Chrome Android1/23/2024 909
html.elements.selectedcontent 📋Chrome Android4/1/2025 475
html.elements.template.shadowrootreferencetarget Chrome Android2/4/2025 Firefox3/24/2026413
html.elements.textarea.autocomplete.webauthn 📋Chrome Android11/29/2022 1329
html.global_attributes.popover.hint 📋Chrome Android2/4/2025 531
html.global_attributes.virtualkeyboardpolicy 📋Chrome Android9/21/2021 1763