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 Safari

Raw Data

Quick Links:

CSS Data

API First Browser Date Last Browser Date Days in experimentation Notes
css.at-rules.keyframes.named_range_keyframes 📋Chrome7/18/2023 1111
css.at-rules.media.display-mode.picture-in-picture 📋Chrome3/19/2024 866
css.at-rules.media.prefers-reduced-data 📋Chrome8/25/2020 2168
css.at-rules.media.prefers-reduced-transparency 📋Chrome10/10/2023 1027
css.at-rules.page.bottom-center 📋Chrome11/12/2024 628
css.at-rules.page.bottom-left 📋Chrome11/12/2024 628
css.at-rules.page.bottom-left-corner 📋Chrome11/12/2024 628
css.at-rules.page.bottom-right 📋Chrome11/12/2024 628
css.at-rules.page.bottom-right-corner 📋Chrome11/12/2024 628
css.at-rules.page.left-bottom 📋Chrome11/12/2024 628
css.at-rules.page.left-middle 📋Chrome11/12/2024 628
css.at-rules.page.left-top 📋Chrome11/12/2024 628
css.at-rules.page.right-bottom 📋Chrome11/12/2024 628
css.at-rules.page.right-middle 📋Chrome11/12/2024 628
css.at-rules.page.right-top 📋Chrome11/12/2024 628
css.at-rules.page.top-center 📋Chrome11/12/2024 628
css.at-rules.page.top-left 📋Chrome11/12/2024 628
css.at-rules.page.top-left-corner 📋Chrome11/12/2024 628
css.at-rules.page.top-right 📋Chrome11/12/2024 628
css.at-rules.page.top-right-corner 📋Chrome11/12/2024 628
css.at-rules.position-try 📋Chrome5/14/2024 810
css.properties.-webkit-app-region Chrome1/10/2013 4952
css.properties.-webkit-column-axis Safari7/25/2012 5121
css.properties.-webkit-column-progression Safari10/22/2013 4667
css.properties.-webkit-cursor-visibility Safari10/22/2013 4667
css.properties.-webkit-hyphenate-limit-after Safari7/20/2011 5492
css.properties.-webkit-hyphenate-limit-before Safari7/20/2011 5492
css.properties.-webkit-hyphenate-limit-lines Safari7/25/2012 5121
css.properties.-webkit-line-align Safari7/25/2012 5121
css.properties.-webkit-line-box-contain Safari7/20/2011 5492
css.properties.-webkit-line-grid Safari7/25/2012 5121
css.properties.-webkit-line-snap Safari7/25/2012 5121
css.properties.-webkit-mask-source-type Safari10/22/2013 4667
css.properties.-webkit-nbsp-mode Safari6/8/2009 6264
css.properties.-webkit-text-zoom Safari9/20/2016 3603
css.properties.align-items.anchor-center 📋Chrome5/14/2024 810
css.properties.align-self.anchor-center 📋Chrome5/14/2024 810
css.properties.anchor-name 📋Chrome5/14/2024 810
css.properties.anchor-name.none 📋Chrome5/14/2024 810
css.properties.anchor-scope 📋Chrome11/12/2024 628
css.properties.anchor-scope.all 📋Chrome11/12/2024 628
css.properties.anchor-scope.none 📋Chrome11/12/2024 628
css.properties.animation-duration.auto 📋Chrome7/18/2023 1111
Firefox: Firefox does not currently support the auto value and only accepts values in seconds or milliseconds. It's recommended that 1ms is used until auto is supported.Firefox for Android: Firefox for Android does not currently support the auto value and only accepts values in seconds or milliseconds. It's recommended that 1ms is used until auto is supported.
css.properties.animation-range 📋Chrome7/18/2023 1111
css.properties.animation-range-end 📋Chrome7/18/2023 1111
css.properties.animation-range-end.normal 📋Chrome7/18/2023 1111
css.properties.animation-range-start 📋Chrome7/18/2023 1111
css.properties.animation-range-start.normal 📋Chrome7/18/2023 1111
css.properties.animation-timeline 📋Chrome7/18/2023 1111
css.properties.animation-timeline.scroll 📋Chrome7/18/2023 1111
Firefox: Zero scroll range is treated as 100% but should be 0% (see bug 1780865).Firefox: Supports the deprecated horizontal and vertical axis values, and not the x and y values.
css.properties.animation-timeline.view 📋Chrome7/18/2023 1111
css.properties.block-size.anchor-size 📋Chrome5/14/2024 810
css.properties.bottom.anchor 📋Chrome5/14/2024 810
css.properties.bottom.anchor-size 📋Chrome1/14/2025 565
css.properties.container-type.scroll-state 📋Chrome2/4/2025 544
css.properties.display.math Chrome1/10/2023 1300
css.properties.field-sizing 📋Chrome3/19/2024 866
css.properties.field-sizing.content 📋Chrome3/19/2024 866
css.properties.field-sizing.fixed 📋Chrome3/19/2024 866
css.properties.font-family.math Chrome1/10/2023 1300
css.properties.font-palette.animation_computed Chrome1/23/2024 922
css.properties.font-palette.palette-mix_function 📋Chrome1/23/2024 922
css.properties.font-variant-emoji.emoji 📋Chrome11/12/2024 628
css.properties.font-variant-emoji.normal 📋Chrome11/12/2024 628
css.properties.font-variant-emoji.text 📋Chrome11/12/2024 628
css.properties.font-variant-emoji.unicode 📋Chrome11/12/2024 628
css.properties.forced-color-adjust.preserve-parent-color 📋Chrome9/27/2022 1405
css.properties.height.anchor-size 📋Chrome5/14/2024 810
css.properties.hyphenate-limit-chars.auto 📋Chrome1/10/2023 1300
css.properties.inline-size.anchor-size 📋Chrome5/14/2024 810
css.properties.inset.anchor 📋Chrome5/14/2024 810
css.properties.inset.anchor-size 📋Chrome1/14/2025 565
css.properties.inset-block.anchor 📋Chrome5/14/2024 810
css.properties.inset-block.anchor-size 📋Chrome1/14/2025 565
css.properties.inset-block-end.anchor 📋Chrome5/14/2024 810
css.properties.inset-block-end.anchor-size 📋Chrome1/14/2025 565
css.properties.inset-block-start.anchor 📋Chrome5/14/2024 810
css.properties.inset-block-start.anchor-size 📋Chrome1/14/2025 565
css.properties.inset-inline.anchor 📋Chrome5/14/2024 810
css.properties.inset-inline.anchor-size 📋Chrome1/14/2025 565
css.properties.inset-inline-end.anchor 📋Chrome5/14/2024 810
css.properties.inset-inline-end.anchor-size 📋Chrome1/14/2025 565
css.properties.inset-inline-start.anchor 📋Chrome5/14/2024 810
css.properties.inset-inline-start.anchor-size 📋Chrome1/14/2025 565
css.properties.interpolate-size 📋Chrome9/17/2024 684
css.properties.interpolate-size.allow-keywords 📋Chrome9/17/2024 684
css.properties.interpolate-size.numeric-only 📋Chrome9/17/2024 684
css.properties.justify-items.anchor-center 📋Chrome5/14/2024 810
css.properties.justify-self.anchor-center 📋Chrome5/14/2024 810
css.properties.left.anchor 📋Chrome5/14/2024 810
css.properties.left.anchor-size 📋Chrome1/14/2025 565
css.properties.line-height-step 📋Chrome7/25/2017 3295
css.properties.margin.anchor-size 📋Chrome1/14/2025 565
css.properties.margin-block.anchor-size 📋Chrome1/14/2025 565
css.properties.margin-block-end.anchor-size 📋Chrome1/14/2025 565
css.properties.margin-block-start.anchor-size 📋Chrome1/14/2025 565
css.properties.margin-bottom.anchor-size 📋Chrome1/14/2025 565
css.properties.margin-inline.anchor-size 📋Chrome1/14/2025 565
css.properties.margin-inline-end.anchor-size 📋Chrome1/14/2025 565
css.properties.margin-inline-start.anchor-size 📋Chrome1/14/2025 565
css.properties.margin-left.anchor-size 📋Chrome1/14/2025 565
css.properties.margin-right.anchor-size 📋Chrome1/14/2025 565
css.properties.margin-top.anchor-size 📋Chrome1/14/2025 565
css.properties.margin-trim 📋Safari3/27/2023 1224
css.properties.margin-trim.block 📋Safari3/27/2023 1224
css.properties.margin-trim.block-end 📋Safari3/27/2023 1224
css.properties.margin-trim.block-start 📋Safari3/27/2023 1224
css.properties.margin-trim.inline 📋Safari3/27/2023 1224
css.properties.margin-trim.inline-end 📋Safari3/27/2023 1224
css.properties.margin-trim.inline-start 📋Safari3/27/2023 1224
css.properties.margin-trim.none 📋Safari3/27/2023 1224
css.properties.math-shift 📋Chrome1/10/2023 1300
css.properties.max-block-size.anchor-size 📋Chrome5/14/2024 810
css.properties.max-height.anchor-size 📋Chrome5/14/2024 810
css.properties.max-height.stretch 📋Chrome7/9/2013 4772
css.properties.max-inline-size.anchor-size 📋Chrome5/14/2024 810
css.properties.max-width.anchor-size 📋Chrome5/14/2024 810
css.properties.max-width.stretch 📋Chrome9/25/2012 5059
css.properties.min-block-size.anchor-size 📋Chrome5/14/2024 810
css.properties.min-height.anchor-size 📋Chrome5/14/2024 810
css.properties.min-height.stretch Chrome7/9/2013 Safari9/30/2015813
css.properties.min-inline-size.anchor-size 📋Chrome5/14/2024 810
css.properties.min-width.anchor-size 📋Chrome5/14/2024 810
css.properties.min-width.stretch Chrome9/25/2012 5059
css.properties.mix-blend-mode.plus-darker 📋Safari3/24/2020 2322
css.properties.object-view-box 📋Chrome8/2/2022 1461
css.properties.object-view-box.none 📋Chrome8/2/2022 1461
css.properties.offset-path.margin-box 📋Safari9/16/2024 685
css.properties.overflow-clip-margin.border-box 📋Chrome8/2/2022 1461
css.properties.overflow-clip-margin.content-box 📋Chrome8/2/2022 1461
css.properties.overflow-clip-margin.padding-box 📋Chrome8/2/2022 1461
css.properties.overlay 📋Chrome9/12/2023 1055
css.properties.overlay.auto 📋Chrome9/12/2023 1055
css.properties.overlay.none 📋Chrome9/12/2023 1055
css.properties.place-items.anchor-center 📋Chrome5/14/2024 810
css.properties.place-self.anchor-center 📋Chrome5/14/2024 810
css.properties.position-anchor 📋Chrome5/14/2024 810
css.properties.position-anchor.auto 📋Chrome5/14/2024 810
Chrome: The generic auto value exists, but it does not yet have the effect described in the spec.Chrome Android: The generic auto value exists, but it does not yet have the effect described in the spec.Edge: The generic auto value exists, but it does not yet have the effect described in the spec.Opera: The generic auto value exists, but it does not yet have the effect described in the spec.Opera Android: The generic auto value exists, but it does not yet have the effect described in the spec.Samsung Internet: The generic auto value exists, but it does not yet have the effect described in the spec.WebView Android: The generic auto value exists, but it does not yet have the effect described in the spec.
css.properties.position-area 📋Chrome9/17/2024 684
css.properties.position-area.block-end 📋Chrome9/17/2024 684
css.properties.position-area.block-start 📋Chrome9/17/2024 684
css.properties.position-area.bottom 📋Chrome9/17/2024 684
css.properties.position-area.center 📋Chrome9/17/2024 684
css.properties.position-area.end 📋Chrome9/17/2024 684
css.properties.position-area.inline-end 📋Chrome9/17/2024 684
css.properties.position-area.inline-start 📋Chrome9/17/2024 684
css.properties.position-area.left 📋Chrome9/17/2024 684
css.properties.position-area.none 📋Chrome9/17/2024 684
css.properties.position-area.right 📋Chrome9/17/2024 684
css.properties.position-area.self-end 📋Chrome9/17/2024 684
css.properties.position-area.self-start 📋Chrome9/17/2024 684
css.properties.position-area.span-all 📋Chrome9/17/2024 684
css.properties.position-area.span-block-end 📋Chrome9/17/2024 684
css.properties.position-area.span-block-start 📋Chrome9/17/2024 684
css.properties.position-area.span-bottom 📋Chrome9/17/2024 684
css.properties.position-area.span-end 📋Chrome9/17/2024 684
css.properties.position-area.span-inline-end 📋Chrome9/17/2024 684
css.properties.position-area.span-inline-start 📋Chrome9/17/2024 684
css.properties.position-area.span-start 📋Chrome9/17/2024 684
css.properties.position-area.span-top 📋Chrome9/17/2024 684
css.properties.position-area.span-x-end 📋Chrome9/17/2024 684
css.properties.position-area.span-x-start 📋Chrome9/17/2024 684
css.properties.position-area.span-y-end 📋Chrome9/17/2024 684
css.properties.position-area.span-y-start 📋Chrome9/17/2024 684
css.properties.position-area.start 📋Chrome9/17/2024 684
css.properties.position-area.top 📋Chrome9/17/2024 684
css.properties.position-area.x-end 📋Chrome9/17/2024 684
css.properties.position-area.x-self-end 📋Chrome9/17/2024 684
css.properties.position-area.x-self-start 📋Chrome9/17/2024 684
css.properties.position-area.x-start 📋Chrome9/17/2024 684
css.properties.position-area.y-end 📋Chrome9/17/2024 684
css.properties.position-area.y-self-end 📋Chrome9/17/2024 684
css.properties.position-area.y-self-start 📋Chrome9/17/2024 684
css.properties.position-area.y-start 📋Chrome9/17/2024 684
css.properties.position-try 📋Chrome5/14/2024 810
css.properties.position-try-fallbacks 📋Chrome8/20/2024 712
css.properties.position-try-fallbacks.flip-block 📋Chrome8/20/2024 712
css.properties.position-try-fallbacks.flip-inline 📋Chrome8/20/2024 712
css.properties.position-try-fallbacks.flip-start 📋Chrome8/20/2024 712
css.properties.position-try-fallbacks.none 📋Chrome8/20/2024 712
css.properties.position-try-fallbacks.position-area 📋Chrome8/20/2024 712
Chrome: inset-area values had to be wrapped inside an inset-area() function.Chrome Android: inset-area values had to be wrapped inside an inset-area() function.Edge: inset-area values had to be wrapped inside an inset-area() function.Opera: inset-area values had to be wrapped inside an inset-area() function.Opera Android: inset-area values had to be wrapped inside an inset-area() function.Samsung Internet: inset-area values had to be wrapped inside an inset-area() function.WebView Android: inset-area values had to be wrapped inside an inset-area() function.
css.properties.position-try-order 📋Chrome5/14/2024 810
css.properties.position-try-order.most-block-size 📋Chrome5/14/2024 810
css.properties.position-try-order.most-height 📋Chrome5/14/2024 810
css.properties.position-try-order.most-inline-size 📋Chrome5/14/2024 810
css.properties.position-try-order.most-width 📋Chrome5/14/2024 810
css.properties.position-try-order.normal 📋Chrome5/14/2024 810
css.properties.position-visibility 📋Chrome5/14/2024 810
css.properties.position-visibility.always 📋Chrome5/14/2024 810
css.properties.position-visibility.anchors-visible 📋Chrome5/14/2024 810
css.properties.position-visibility.no-overflow 📋Chrome5/14/2024 810
css.properties.reading-flow 📋Chrome8/20/2024 712
css.properties.right.anchor 📋Chrome5/14/2024 810
css.properties.right.anchor-size 📋Chrome1/14/2025 565
css.properties.scroll-initial-target 📋Chrome2/4/2025 544
css.properties.scroll-initial-target.nearest 📋Chrome2/4/2025 544
css.properties.scroll-initial-target.none 📋Chrome2/4/2025 544
css.properties.scroll-timeline 📋Chrome7/18/2023 1111
Firefox: The syntax of the shorthand property uses the fixed order of name and then the axis.Firefox: Supports the deprecated horizontal and vertical axis values, and not the x and y values.Firefox: The @scroll-timeline at-rule is replaced with the longhand properties scroll-timeline-name and scroll-timeline-axis and the shorthand property scroll-timeline.
css.properties.scroll-timeline-axis 📋Chrome7/18/2023 1111
Firefox: The syntax of the shorthand property uses the fixed order of name and then the axis.Firefox: Supports the deprecated horizontal and vertical values, and not the x and y values.Firefox: The @scroll-timeline at-rule is replaced with the longhand properties scroll-timeline-name and scroll-timeline-axis and the shorthand property scroll-timeline.
css.properties.scroll-timeline-axis.block 📋Chrome7/18/2023 1111
css.properties.scroll-timeline-axis.inline 📋Chrome7/18/2023 1111
css.properties.scroll-timeline-axis.x 📋Chrome7/18/2023 1111
css.properties.scroll-timeline-axis.y 📋Chrome7/18/2023 1111
css.properties.scroll-timeline-name 📋Chrome7/18/2023 1111
Firefox: The syntax of the shorthand property uses the fixed order of name and then the axis.Firefox: The @scroll-timeline at-rule is replaced with the longhand properties scroll-timeline-name and scroll-timeline-axis and the shorthand property scroll-timeline.
css.properties.speak-as 📋Safari4/12/2018 3034
css.properties.speak-as.digits 📋Safari4/12/2018 3034
css.properties.speak-as.literal-punctuation 📋Safari4/12/2018 3034
css.properties.speak-as.no-punctuation 📋Safari4/12/2018 3034
css.properties.speak-as.normal 📋Safari4/12/2018 3034
css.properties.speak-as.spell-out 📋Safari4/12/2018 3034
css.properties.stroke-color 📋Safari3/24/2020 2322
css.properties.text-decoration-line.grammar-error 📋Chrome1/23/2024 922
css.properties.text-decoration-line.spelling-error 📋Chrome1/23/2024 922
css.properties.text-decoration-skip 📋Safari3/25/2019 2687
Chrome: Only supports the deprecated ink value.Chrome Android: Only supports the deprecated ink value.Opera: Only supports the deprecated ink value.Opera Android: Only supports the deprecated ink value.Safari: Supports only none, auto, and objects values.Safari: Supports only none, auto, and objects values.Safari on iOS: Supports only none, auto, and objects values.Safari on iOS: Supports only none, auto, and objects values.Samsung Internet: Only supports the deprecated ink value.WebView Android: Only supports the deprecated ink value.WebView on iOS: Supports only none, auto, and objects values.WebView on iOS: Supports only none, auto, and objects values.
css.properties.text-decoration-skip.auto 📋Safari3/24/2020 2322
css.properties.text-decoration-skip.none 📋Safari3/24/2020 2322
css.properties.text-size-adjust 📋Chrome10/12/2016 3581
css.properties.text-size-adjust.auto 📋Chrome10/12/2016 3581
css.properties.text-size-adjust.none 📋Chrome10/12/2016 3581
css.properties.text-size-adjust.percentages 📋Chrome10/12/2016 3581
css.properties.text-spacing-trim 📋Chrome3/19/2024 866
css.properties.text-spacing-trim.normal 📋Chrome3/19/2024 866
css.properties.text-spacing-trim.space-all 📋Chrome3/19/2024 866
css.properties.text-spacing-trim.space-first 📋Chrome3/19/2024 866
css.properties.text-spacing-trim.trim-start 📋Chrome3/19/2024 866
css.properties.text-wrap-style.pretty 📋Chrome10/15/2024 656
css.properties.timeline-scope 📋Chrome8/15/2023 1083
css.properties.timeline-scope.all 📋Chrome8/15/2023 1083
css.properties.timeline-scope.none 📋Chrome8/15/2023 1083
css.properties.top.anchor 📋Chrome5/14/2024 810
css.properties.top.anchor-size 📋Chrome1/14/2025 565
css.properties.view-timeline 📋Chrome7/18/2023 1111
Firefox: Now supports the x and y values, and also the deprecated horizontal and vertical values.
css.properties.view-timeline-axis 📋Chrome7/18/2023 1111
Firefox: Now supports the x and y values, and also the deprecated horizontal and vertical values.
css.properties.view-timeline-axis.block 📋Chrome7/18/2023 1111
css.properties.view-timeline-axis.inline 📋Chrome7/18/2023 1111
css.properties.view-timeline-axis.x 📋Chrome7/18/2023 1111
css.properties.view-timeline-axis.y 📋Chrome7/18/2023 1111
css.properties.view-timeline-inset 📋Chrome7/18/2023 1111
css.properties.view-timeline-inset.auto 📋Chrome7/18/2023 1111
css.properties.view-timeline-name 📋Chrome7/18/2023 1111
css.properties.white-space.shorthand_values Chrome5/30/2023 1160
Chrome: Only accepts values for white-space-collapse and text-wrap-mode, not white-space-trim.Chrome Android: Only accepts values for white-space-collapse and text-wrap-mode, not white-space-trim.Edge: Only accepts values for white-space-collapse and text-wrap-mode, not white-space-trim.Opera: Only accepts values for white-space-collapse and text-wrap-mode, not white-space-trim.Opera Android: Only accepts values for white-space-collapse and text-wrap-mode, not white-space-trim.Samsung Internet: Only accepts values for white-space-collapse and text-wrap-mode, not white-space-trim.WebView Android: Only accepts values for white-space-collapse and text-wrap-mode, not white-space-trim.
css.properties.width.anchor-size 📋Chrome5/14/2024 810
css.properties.word-break.auto-phrase 📋Chrome10/31/2023 1006
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.-webkit-slider-runnable-track Chrome5/19/2020 2266
css.selectors.-webkit-slider-thumb Chrome5/19/2020 2266
css.selectors.active-view-transition-type 📋Chrome5/14/2024 810
css.selectors.details-content 📋Chrome11/12/2024 628
css.selectors.open 📋Chrome2/4/2025 544
Chrome: The selector is recognized, but has no effect.Chrome Android: The selector is recognized, but has no effect.Edge: The selector is recognized, but has no effect.Opera: The selector is recognized, but has no effect.Opera Android: The selector is recognized, but has no effect.Samsung Internet: The selector is recognized, but has no effect.WebView Android: The selector is recognized, but has no effect.
css.selectors.xr-overlay 📋Chrome5/19/2020 2266
css.types.anchor 📋Chrome5/14/2024 810
css.types.anchor-size 📋Chrome5/14/2024 810
css.types.anchor-size.inset_margin Chrome1/14/2025 565
css.types.attr.type-or-unit Chrome2/4/2025 544
css.types.calc-size 📋Chrome9/17/2024 684