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 FirefoxNot in Safari
In Firefox 190
In Safari 344

Unstable APIs

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

Raw Data

Quick Links:

CSS Data

API First Browser Date Days in Limbo Notes
css.at-rules.container.style_queries_for_custom_properties 📋Safari9/16/2024549
Safari: The document element cannot be a container. See bug 271040.Safari on iOS: The document element cannot be a container. See bug 271040.WebView on iOS: The document element cannot be a container. See bug 271040.
css.at-rules.counter-style.speak-as 📋Firefox10/14/20144174
css.at-rules.custom-media 📋Firefox2/24/202623
css.at-rules.document Firefox6/26/20182823
Firefox: Only supports an empty url-prefix() value, which is supported due to its use in Firefox browser detection. Still supported in user stylesheets.Firefox for Android: Only supports an empty url-prefix() value, which is supported due to its use in Firefox for Android browser detection. Still supported in user stylesheets.
css.at-rules.font-face.OpenType_COLRv1 Firefox11/15/20221220
css.at-rules.font-face.OpenType_SBIX Safari3/21/20163650
css.at-rules.font-face.SVG_fonts Safari3/18/20086575
css.at-rules.font-face.ascent-override 📋Firefox6/1/20211752
css.at-rules.font-face.descent-override 📋Firefox6/1/20211752
css.at-rules.font-face.font-variation-settings 📋Firefox9/5/20182752
css.at-rules.font-face.font-width 📋Safari3/31/2025353
css.at-rules.font-face.line-gap-override 📋Firefox6/1/20211752
css.at-rules.font-face.src.drop_invalid_item Firefox1/17/20231157
Chrome: Chrome drops invalid item for tech() but not other invalid valuesChrome Android: Chrome Android drops invalid item for tech() but not other invalid valuesEdge: Edge drops invalid item for tech() but not other invalid valuesOpera: Opera drops invalid item for tech() but not other invalid valuesOpera Android: Opera Android drops invalid item for tech() but not other invalid valuesSamsung Internet: Samsung Internet drops invalid item for tech() but not other invalid valuesWebView Android: WebView Android drops invalid item for tech() but not other invalid values
css.at-rules.keyframes.named_range_keyframes 📋Safari9/15/2025185
css.at-rules.media.-moz-device-pixel-ratio Firefox3/22/20115476
css.at-rules.media.-webkit-animation Safari6/8/20096128
css.at-rules.media.-webkit-transform-2d Safari6/8/20096128
css.at-rules.media.-webkit-transition Safari6/8/20096128
css.at-rules.media.color-index 📋Safari10/16/20144172
css.at-rules.media.media_query_values Firefox3/13/20182928
css.at-rules.media.prefers-color-scheme.respects-inherited-scheme Firefox9/20/20221276
Chrome: Only supports SVG images, not iframes.Chrome Android: Only supports SVG images, not iframes.Edge: Only supports SVG images, not iframes.Opera: Only supports SVG images, not iframes.Opera Android: Only supports SVG images, not iframes.Samsung Internet: Only supports SVG images, not iframes.WebView Android: Only supports SVG images, not iframes.
css.at-rules.media.prefers-reduced-transparency 📋Firefox5/9/20231045
css.at-rules.media.video-dynamic-range 📋Firefox5/3/20221416
css.at-rules.page.page-orientation 📋Firefox1/23/2024786
css.at-rules.view-transition 📋Safari12/11/2024463
css.properties.-moz-float-edge Firefox11/9/20047800
css.properties.-moz-force-broken-image-icon Firefox11/9/20047800
css.properties.-moz-orient Firefox8/16/20115329
css.properties.-moz-orient.block Firefox8/11/20153873
css.properties.-moz-orient.inline Firefox8/11/20153873
css.properties.-webkit-border-before Safari7/20/20115356
css.properties.-webkit-border-horizontal-spacing Safari6/8/20096128
css.properties.-webkit-border-vertical-spacing Safari6/8/20096128
css.properties.-webkit-box-reflect Safari6/8/20096128
css.properties.-webkit-column-axis Safari7/25/20124985
css.properties.-webkit-column-break-after Safari6/8/20096128
css.properties.-webkit-column-break-before Safari6/8/20096128
css.properties.-webkit-column-break-inside Safari6/8/20096128
css.properties.-webkit-column-progression Safari10/22/20134531
css.properties.-webkit-cursor-visibility Safari10/22/20134531
css.properties.-webkit-hyphenate-limit-after Safari7/20/20115356
css.properties.-webkit-hyphenate-limit-before Safari7/20/20115356
css.properties.-webkit-hyphenate-limit-lines Safari7/25/20124985
css.properties.-webkit-line-align Safari7/25/20124985
css.properties.-webkit-line-box-contain Safari7/20/20115356
css.properties.-webkit-line-grid Safari7/25/20124985
css.properties.-webkit-line-snap Safari7/25/20124985
css.properties.-webkit-locale Safari7/20/20115356
css.properties.-webkit-logical-height Safari7/20/20115356
css.properties.-webkit-logical-width Safari7/20/20115356
css.properties.-webkit-margin-after Safari7/20/20115356
css.properties.-webkit-margin-before Safari7/20/20115356
css.properties.-webkit-mask-box-image Safari3/18/20086575
css.properties.-webkit-mask-composite Safari3/18/20086575
css.properties.-webkit-mask-source-type Safari10/22/20134531
css.properties.-webkit-max-logical-height Safari7/20/20115356
css.properties.-webkit-max-logical-width Safari7/20/20115356
css.properties.-webkit-min-logical-height Safari7/20/20115356
css.properties.-webkit-min-logical-width Safari7/20/20115356
css.properties.-webkit-nbsp-mode Safari6/8/20096128
css.properties.-webkit-perspective-origin-x Safari6/8/20096128
css.properties.-webkit-perspective-origin-y Safari6/8/20096128
css.properties.-webkit-rtl-ordering Safari6/8/20096128
css.properties.-webkit-text-combine Safari7/20/20115356
css.properties.-webkit-text-zoom Safari9/20/20163467
css.properties.-webkit-transform-origin-x Safari6/8/20096128
css.properties.-webkit-transform-origin-y Safari6/8/20096128
css.properties.-webkit-transform-origin-z Safari6/8/20096128
css.properties.-webkit-user-drag Safari6/8/20096128
css.properties.align-content.multicol_context 📋Safari3/5/2024744
css.properties.align-self.position_absolute_context 📋Firefox1/7/2025436
css.properties.alignment-baseline 📋Safari7/20/20115356
css.properties.alignment-baseline.alphabetic Safari7/20/20115356
css.properties.alignment-baseline.baseline Safari7/20/20115356
css.properties.alignment-baseline.central Safari7/20/20115356
css.properties.alignment-baseline.ideographic Safari7/20/20115356
css.properties.alignment-baseline.mathematical Safari7/20/20115356
css.properties.alignment-baseline.middle Safari7/20/20115356
css.properties.alignment-baseline.text-after-edge Safari7/20/20115356
css.properties.alignment-baseline.text-before-edge Safari7/20/20115356
css.properties.animation-duration.auto 📋Safari3/31/2025353
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 📋Safari9/15/2025185
css.properties.animation-range.normal 📋Safari9/15/2025185
css.properties.animation-range-end 📋Safari9/15/2025185
css.properties.animation-range-end.normal 📋Safari9/15/2025185
css.properties.animation-range-start 📋Safari9/15/2025185
css.properties.animation-range-start.normal 📋Safari9/15/2025185
css.properties.animation-timeline.auto 📋Safari9/15/2025185
css.properties.animation-timeline.none 📋Safari9/15/2025185
css.properties.background.x-end 📋Safari9/15/2025185
css.properties.background.x-start 📋Safari9/15/2025185
css.properties.background.y-end 📋Safari9/15/2025185
css.properties.background.y-start 📋Safari9/15/2025185
css.properties.background-clip.border-area 📋Safari12/11/2024463
css.properties.background-image.element 📋Firefox3/22/20115476
css.properties.background-position.x-end 📋Safari9/15/2025185
css.properties.background-position.x-start 📋Safari9/15/2025185
css.properties.background-position.y-end 📋Safari9/15/2025185
css.properties.background-position.y-start 📋Safari9/15/2025185
css.properties.background-position-x.x-end 📋Safari9/15/2025185
css.properties.background-position-x.x-start 📋Safari9/15/2025185
css.properties.background-position-y.y-end 📋Safari9/15/2025185
css.properties.background-position-y.y-start 📋Safari9/15/2025185
css.properties.baseline-shift 📋Safari6/8/20096128
css.properties.baseline-shift.baseline 📋Safari6/8/20096128
css.properties.baseline-shift.sub 📋Safari6/8/20096128
css.properties.baseline-shift.super 📋Safari6/8/20096128
css.properties.baseline-source 📋Firefox7/4/2023989
css.properties.baseline-source.auto 📋Firefox7/4/2023989
css.properties.baseline-source.first 📋Firefox7/4/2023989
css.properties.baseline-source.last 📋Firefox7/4/2023989
css.properties.block-size.fit-content_function Firefox8/10/20211682
css.properties.box-flex-group Safari10/26/20076719
css.properties.box-lines Safari10/26/20076719
css.properties.break-after.always Firefox1/29/20192606
css.properties.break-after.avoid-column Safari9/20/20163467
css.properties.break-after.avoid-page Safari9/20/20163467
css.properties.break-after.column Safari9/20/20163467
css.properties.break-after.multicol_context 📋Firefox1/29/20192606
Firefox: Only supported in print mode. See bug 1675322.Firefox for Android: Only supported in print mode. See bug 1675322.
css.properties.break-after.multicol_context.always Firefox1/29/20192606
Firefox: Only supported in print mode. See bug 1675322.Firefox for Android: Only supported in print mode. See bug 1675322.
css.properties.break-after.paged_context.always Firefox1/29/20192606
css.properties.break-after.paged_context.avoid-page Safari9/20/20163467
css.properties.break-after.recto Safari9/20/20163467
css.properties.break-after.verso Safari9/20/20163467
css.properties.break-before.always Firefox1/29/20192606
css.properties.break-before.avoid-column Safari9/20/20163467
css.properties.break-before.avoid-page Safari9/20/20163467
css.properties.break-before.column Safari9/20/20163467
css.properties.break-before.multicol_context 📋Firefox1/29/20192606
Firefox: Only supported in print mode. See bug 1675322.Firefox for Android: Only supported in print mode. See bug 1675322.
css.properties.break-before.multicol_context.always Firefox1/29/20192606
Firefox: Only supported in print mode. See bug 1675322.Firefox for Android: Only supported in print mode. See bug 1675322.
css.properties.break-before.paged_context.always Firefox1/29/20192606
css.properties.break-before.recto Safari9/20/20163467
css.properties.break-before.verso Safari9/20/20163467
css.properties.break-inside.paged_context.avoid-page Firefox9/7/20211654
css.properties.buffered-rendering Safari10/22/20134531
css.properties.buffered-rendering.auto Safari10/22/20134531
css.properties.buffered-rendering.dynamic Safari10/22/20134531
css.properties.buffered-rendering.static Safari10/22/20134531
css.properties.caption-side.writing-mode_relative_values Firefox11/3/20153789
css.properties.color-interpolation.linearGradient Firefox2/20/2024758
css.properties.content.none_applies_to_elements Firefox8/10/20211682
css.properties.content-visibility.is_transitionable 📋Safari9/16/2024549
css.properties.content-visibility.keyframe_animatable 📋Safari9/16/2024549
css.properties.counter-reset.reset_does_not_affect_siblings Firefox10/20/20201976
css.properties.counter-reset.reversed 📋Firefox1/11/20221528
css.properties.d 📋Firefox2/8/20221500
Safari: The property parses, but has no effect.Safari on iOS: The property parses, but has no effect.WebView on iOS: The property parses, but has no effect.
css.properties.d.none 📋Firefox2/8/20221500
css.properties.display.contents.contents_unusual 📋Firefox3/13/20182928
css.properties.display.is_transitionable 📋Safari9/16/2024549
css.properties.display.keyframe_animatable 📋Safari9/16/2024549
css.properties.display.list-item.legend-support Firefox12/11/20182655
css.properties.display.none.option_is_hidden Firefox11/9/20047800
css.properties.display.ruby Firefox5/12/20153964
css.properties.display.ruby-base Firefox5/12/20153964
css.properties.display.ruby-base-container Firefox5/12/20153964
css.properties.display.ruby-text Firefox5/12/20153964
css.properties.display.ruby-text-container Firefox5/12/20153964
css.properties.dynamic-range-limit 📋Safari9/15/2025185
css.properties.dynamic-range-limit.no-limit 📋Safari9/15/2025185
css.properties.dynamic-range-limit.standard 📋Safari9/15/2025185
css.properties.field-sizing 📋Safari12/12/202597
css.properties.field-sizing.content 📋Safari12/12/202597
css.properties.field-sizing.fixed 📋Safari12/12/202597
css.properties.filter.svg_elements Firefox1/13/20154083
css.properties.flex-grow.less_than_zero_animate Firefox9/2/20144216
Firefox: Before Firefox 32, Firefox wasn't able to animate values starting or stopping at 0.Firefox for Android: Before Firefox for Android 32, Firefox for Android wasn't able to animate values starting or stopping at 0.
css.properties.font-family.ui-monospace Safari3/24/20202186
css.properties.font-family.ui-rounded Safari3/24/20202186
css.properties.font-family.ui-sans-serif Safari3/24/20202186
css.properties.font-family.ui-serif Safari3/24/20202186
css.properties.font-language-override 📋Firefox12/1/20144126
css.properties.font-language-override.normal 📋Firefox3/22/20115476
css.properties.font-size.math Firefox8/29/2023933
css.properties.font-synthesis.position Firefox9/26/2023905
css.properties.font-synthesis-position 📋Firefox9/26/2023905
css.properties.font-synthesis-position.auto 📋Firefox9/26/2023905
css.properties.font-synthesis-position.none 📋Firefox9/26/2023905
css.properties.font-synthesis-style.oblique-only 📋Firefox4/1/2025352
css.properties.font-variant-emoji.emoji 📋Firefox7/22/2025240
css.properties.font-variant-emoji.normal 📋Firefox7/22/2025240
css.properties.font-variant-emoji.text 📋Firefox7/22/2025240
css.properties.font-variant-emoji.unicode 📋Firefox7/22/2025240
css.properties.font-width 📋Safari3/31/2025353
css.properties.font-width.condensed 📋Safari3/31/2025353
css.properties.font-width.expanded 📋Safari3/31/2025353
css.properties.font-width.extra-condensed 📋Safari3/31/2025353
css.properties.font-width.extra-expanded 📋Safari3/31/2025353
css.properties.font-width.normal 📋Safari3/31/2025353
css.properties.font-width.percentage 📋Safari3/31/2025353
css.properties.font-width.semi-condensed 📋Safari3/31/2025353
css.properties.font-width.semi-expanded 📋Safari3/31/2025353
css.properties.font-width.ultra-condensed 📋Safari3/31/2025353
css.properties.font-width.ultra-expanded 📋Safari3/31/2025353
css.properties.forced-color-adjust 📋Firefox5/9/20231045
css.properties.forced-color-adjust.auto 📋Firefox5/9/20231045
css.properties.forced-color-adjust.none 📋Firefox5/9/20231045
css.properties.glyph-orientation-vertical 📋Safari6/8/20096128
css.properties.grid-template-columns.masonry 📋Firefox6/2/20202116
css.properties.grid-template-rows.masonry 📋Firefox6/2/20202116
css.properties.hanging-punctuation 📋Safari9/20/20163467
Safari: The characters U+0027 and U+0022 are not supported by the first and last keywords.Safari on iOS: The characters U+0027 and U+0022 are not supported by the first and last keywords.WebView on iOS: The characters U+0027 and U+0022 are not supported by the first and last keywords.
css.properties.hanging-punctuation.allow-end 📋Safari9/20/20163467
css.properties.hanging-punctuation.first 📋Safari9/20/20163467
css.properties.hanging-punctuation.last 📋Safari9/20/20163467
css.properties.hanging-punctuation.none 📋Safari9/20/20163467
css.properties.height.fit-content_function 📋Firefox8/10/20211682
css.properties.hyphenate-limit-chars 📋Firefox4/1/2025352
css.properties.hyphenate-limit-chars.auto 📋Firefox4/1/2025352
css.properties.hyphens.language_afrikaans Firefox11/8/20115245
css.properties.hyphens.language_bosnian Firefox11/8/20115245
css.properties.hyphens.language_bulgarian Firefox11/8/20115245
css.properties.hyphens.language_esperanto Firefox11/8/20115245
css.properties.hyphens.language_estonian Firefox11/8/20115245
css.properties.hyphens.language_galician Firefox12/20/20115203
css.properties.hyphens.language_german_swiss_orthography Firefox11/8/20115245
css.properties.hyphens.language_german_traditional_orthography Firefox11/8/20115245
css.properties.hyphens.language_icelandic Firefox11/8/20115245
css.properties.hyphens.language_interlingua Firefox11/8/20115245
css.properties.hyphens.language_kurmanji Firefox11/8/20115245
css.properties.hyphens.language_latin Firefox11/8/20115245
css.properties.hyphens.language_lithuanian Firefox11/8/20115245
css.properties.hyphens.language_mongolian Firefox11/8/20115245
css.properties.hyphens.language_norwegian_nn Firefox11/8/20115245
css.properties.hyphens.language_slovak Firefox9/3/2024562
css.properties.hyphens.language_slovenian Firefox11/8/20115245
css.properties.hyphens.language_upper_sorbian Firefox11/8/20115245
css.properties.hyphens.language_welsh Firefox11/8/20115245
css.properties.image-rendering.smooth 📋Firefox10/5/20211626
css.properties.ime-mode 📋Firefox6/17/20086484
css.properties.initial-letter 📋Safari9/30/20153823
Safari: See bug 229090 for the unprefixed property.Safari on iOS: See bug 229090 for the unprefixed property.Safari on iOS: Does not support decimal values. See bug 296785.WebView on iOS: See bug 229090 for the unprefixed property.WebView on iOS: Does not support decimal values. See bug 296785.
css.properties.initial-letter.normal 📋Safari9/30/20153823
css.properties.inline-size.fit-content_function Firefox8/10/20211682
css.properties.justify-self.position_absolute_context 📋Firefox1/7/2025436
css.properties.list-style.symbols 📋Firefox1/13/20154083
css.properties.list-style-type.afar Safari6/7/20105764
css.properties.list-style-type.amharic Safari6/7/20105764
css.properties.list-style-type.amharic-abegede Safari6/7/20105764
css.properties.list-style-type.asterisks Safari7/20/20115356
css.properties.list-style-type.binary Safari6/7/20105764
css.properties.list-style-type.ethiopic Safari6/7/20105764
css.properties.list-style-type.ethiopic-abegede Safari6/7/20105764
css.properties.list-style-type.ethiopic-abegede-am-et Safari6/7/20105764
css.properties.list-style-type.ethiopic-abegede-gez Safari6/7/20105764
css.properties.list-style-type.ethiopic-abegede-ti-er Safari6/7/20105764
css.properties.list-style-type.ethiopic-abegede-ti-et Safari6/7/20105764
css.properties.list-style-type.ethiopic-halehame-aa-er Safari6/7/20105764
css.properties.list-style-type.ethiopic-halehame-aa-et Safari6/7/20105764
css.properties.list-style-type.ethiopic-halehame-am-et Safari6/7/20105764
css.properties.list-style-type.ethiopic-halehame-gez Safari6/7/20105764
css.properties.list-style-type.ethiopic-halehame-om-et Safari6/7/20105764
css.properties.list-style-type.ethiopic-halehame-sid-et Safari6/7/20105764
css.properties.list-style-type.ethiopic-halehame-so-et Safari6/7/20105764
css.properties.list-style-type.ethiopic-halehame-tig Safari6/7/20105764
css.properties.list-style-type.footnotes Safari7/20/20115356
css.properties.list-style-type.lower-hexadecimal Safari6/7/20105764
css.properties.list-style-type.lower-norwegian Safari6/7/20105764
css.properties.list-style-type.octal Safari6/7/20105764
css.properties.list-style-type.oromo Safari6/7/20105764
css.properties.list-style-type.sidama Safari6/7/20105764
css.properties.list-style-type.somali Safari6/7/20105764
css.properties.list-style-type.symbols 📋Firefox1/13/20154083
css.properties.list-style-type.tigre Safari6/7/20105764
css.properties.list-style-type.tigrinya-er Safari6/7/20105764
css.properties.list-style-type.tigrinya-er-abegede Safari6/7/20105764
css.properties.list-style-type.tigrinya-et Safari6/7/20105764
css.properties.list-style-type.tigrinya-et-abegede Safari6/7/20105764
css.properties.list-style-type.upper-greek Safari6/23/20038305
css.properties.list-style-type.upper-hexadecimal Safari6/7/20105764
css.properties.list-style-type.upper-norwegian Safari6/7/20105764
css.properties.margin-trim 📋Safari3/27/20231088
css.properties.margin-trim.block 📋Safari3/27/20231088
css.properties.margin-trim.block-end 📋Safari3/27/20231088
css.properties.margin-trim.block-start 📋Safari3/27/20231088
css.properties.margin-trim.inline 📋Safari3/27/20231088
css.properties.margin-trim.inline-end 📋Safari3/27/20231088
css.properties.margin-trim.inline-start 📋Safari3/27/20231088
css.properties.margin-trim.none 📋Safari3/27/20231088
css.properties.mask.x-end 📋Safari9/15/2025185
css.properties.mask.x-start 📋Safari9/15/2025185
css.properties.mask.y-end 📋Safari9/15/2025185
css.properties.mask.y-start 📋Safari9/15/2025185
css.properties.mask-border 📋Safari12/11/2023829
css.properties.mask-border-outset 📋Safari12/11/2023829
css.properties.mask-border-repeat 📋Safari12/11/2023829
css.properties.mask-border-slice 📋Safari12/11/2023829
css.properties.mask-border-source 📋Safari12/11/2023829
css.properties.mask-border-width 📋Safari12/11/2023829
css.properties.mask-clip.border Safari6/8/20096128
Chrome: Only works when using -webkit-mask-clip.Chrome Android: Only works when using -webkit-mask-clip.Edge: Only works when using -webkit-mask-clip.Quest Browser: Only works when using -webkit-mask-clip.Opera: Only works when using -webkit-mask-clip.Opera Android: Only works when using -webkit-mask-clip.Samsung Internet: Only works when using -webkit-mask-clip.
css.properties.mask-clip.border-box Firefox4/19/20173256
css.properties.mask-clip.content Safari6/8/20096128
Chrome: Only works when using -webkit-mask-clip.Chrome Android: Only works when using -webkit-mask-clip.Edge: Only works when using -webkit-mask-clip.Quest Browser: Only works when using -webkit-mask-clip.Opera: Only works when using -webkit-mask-clip.Opera Android: Only works when using -webkit-mask-clip.Samsung Internet: Only works when using -webkit-mask-clip.
css.properties.mask-clip.content-box Firefox4/19/20173256
css.properties.mask-clip.fill-box Firefox4/19/20173256
css.properties.mask-clip.no-clip Firefox4/19/20173256
css.properties.mask-clip.padding Safari6/8/20096128
Chrome: Only works when using -webkit-mask-clip.Chrome Android: Only works when using -webkit-mask-clip.Edge: Only works when using -webkit-mask-clip.Quest Browser: Only works when using -webkit-mask-clip.Opera: Only works when using -webkit-mask-clip.Opera Android: Only works when using -webkit-mask-clip.Samsung Internet: Only works when using -webkit-mask-clip.
css.properties.mask-clip.padding-box Firefox4/19/20173256
css.properties.mask-clip.stroke-box Firefox4/19/20173256
css.properties.mask-clip.text Safari6/8/20096128
Chrome: Only works when using -webkit-mask-clip.Chrome Android: Only works when using -webkit-mask-clip.Edge: Only works when using -webkit-mask-clip.Quest Browser: Only works when using -webkit-mask-clip.Opera: Only works when using -webkit-mask-clip.Opera Android: Only works when using -webkit-mask-clip.Samsung Internet: Only works when using -webkit-mask-clip.
css.properties.mask-clip.view-box Firefox4/19/20173256
css.properties.mask-origin.border Safari3/14/20221466
css.properties.mask-origin.border-box Firefox4/19/20173256
css.properties.mask-origin.content Safari3/14/20221466
css.properties.mask-origin.content-box Firefox4/19/20173256
css.properties.mask-origin.fill-box Firefox4/19/20173256
css.properties.mask-origin.padding Safari3/14/20221466
css.properties.mask-origin.padding-box Firefox4/19/20173256
css.properties.mask-origin.stroke-box Firefox4/19/20173256
css.properties.mask-origin.view-box Firefox4/19/20173256
css.properties.mask-position.x-end 📋Safari9/15/2025185
css.properties.mask-position.x-start 📋Safari9/15/2025185
css.properties.mask-position.y-end 📋Safari9/15/2025185
css.properties.mask-position.y-start 📋Safari9/15/2025185
css.properties.math-depth 📋Firefox8/29/2023933
css.properties.math-depth.auto-add 📋Firefox8/29/2023933
css.properties.max-block-size.fit-content_function Firefox8/10/20211682
css.properties.max-height.fit-content_function 📋Firefox8/10/20211682
css.properties.max-height.stretch 📋Safari9/30/20153823
css.properties.max-inline-size.fit-content_function Firefox8/10/20211682
css.properties.max-width.fit-content_function 📋Firefox8/10/20211682
css.properties.max-width.stretch 📋Safari10/22/20134531
css.properties.min-block-size.fit-content_function Firefox8/10/20211682
css.properties.min-height.fit-content_function 📋Firefox8/10/20211682
css.properties.min-height.stretch Safari9/30/20153823
css.properties.min-inline-size.fit-content_function Firefox8/10/20211682
css.properties.min-width.fit-content_function 📋Firefox8/10/20211682
css.properties.min-width.stretch Safari10/22/20134531
css.properties.mix-blend-mode.plus-darker 📋Safari9/30/20153823
css.properties.mix-blend-mode.svg_elements Firefox9/2/20144216
css.properties.object-position.x-end 📋Safari9/15/2025185
css.properties.object-position.x-start 📋Safari9/15/2025185
css.properties.object-position.y-end 📋Safari9/15/2025185
css.properties.object-position.y-start 📋Safari9/15/2025185
css.properties.offset.margin-box 📋Safari9/12/20221284
css.properties.offset.x-end 📋Safari9/15/2025185
css.properties.offset.x-start 📋Safari9/15/2025185
css.properties.offset.y-end 📋Safari9/15/2025185
css.properties.offset.y-start 📋Safari9/15/2025185
css.properties.offset-anchor.x-end 📋Safari9/15/2025185
css.properties.offset-anchor.x-start 📋Safari9/15/2025185
css.properties.offset-anchor.y-end 📋Safari9/15/2025185
css.properties.offset-anchor.y-start 📋Safari9/15/2025185
css.properties.offset-path.margin-box 📋Safari9/16/2024549
css.properties.offset-position.x-end 📋Safari9/15/2025185
css.properties.offset-position.x-start 📋Safari9/15/2025185
css.properties.offset-position.y-end 📋Safari9/15/2025185
css.properties.offset-position.y-start 📋Safari9/15/2025185
css.properties.orphans 📋Safari4/15/20057643
css.properties.overflow.replaced_elements 📋Firefox2/24/202623
css.properties.overflow-anchor 📋Firefox3/19/20192557
css.properties.overflow-anchor.auto 📋Firefox3/19/20192557
css.properties.overflow-anchor.none 📋Firefox3/19/20192557
css.properties.overflow-block.overlay Firefox4/11/20231073
css.properties.overflow-clip-margin 📋Firefox6/28/20221360
Chrome: Only works when both axes are using overflow: clip. See bug 40235584.Chrome Android: Only works when both axes are using overflow: clip. See bug 40235584.Edge: Only works when both axes are using overflow: clip. See bug 40235584.Firefox: Only supports using a length, not a visual box. See bug 1661582.Firefox for Android: Only supports using a length, not a visual box. See bug 1661582.Quest Browser: Only works when both axes are using overflow: clip. See bug 40235584.Opera: Only works when both axes are using overflow: clip. See bug 40235584.Opera Android: Only works when both axes are using overflow: clip. See bug 40235584.Samsung Internet: Only works when both axes are using overflow: clip. See bug 40235584.WebView Android: Only works when both axes are using overflow: clip. See bug 40235584.
css.properties.overflow-clip-margin.border-box 📋Firefox2/24/202623
css.properties.overflow-clip-margin.content-box 📋Firefox2/24/202623
css.properties.overflow-clip-margin.padding-box 📋Firefox2/24/202623
css.properties.overflow-inline.overlay 📋Firefox4/11/20231073
css.properties.overflow-x.replaced_elements 📋Firefox2/24/202623
css.properties.overflow-y.replaced_elements 📋Firefox2/24/202623
css.properties.perspective-origin.x-end 📋Safari9/15/2025185
css.properties.perspective-origin.x-start 📋Safari9/15/2025185
css.properties.perspective-origin.y-end 📋Safari9/15/2025185
css.properties.perspective-origin.y-start 📋Safari9/15/2025185
css.properties.place-self.position_absolute_context 📋Firefox1/7/2025436
css.properties.pointer-events.bounding-box 📋Safari9/19/20192373
css.properties.position-anchor.none Firefox1/13/202665
css.properties.ruby-overhang 📋Safari12/11/2024463
css.properties.ruby-overhang.auto 📋Safari12/11/2024463
css.properties.ruby-overhang.none 📋Safari12/11/2024463
css.properties.ruby-position.alternate Firefox4/19/20211795
css.properties.ruby-position.inter-character Safari12/11/2024463
Chrome: This value is only supported with the prefixed version of the property.Chrome Android: This value is only supported with the prefixed version of the property.Edge: This value is only supported with the prefixed version of the property.Quest Browser: This value is only supported with the prefixed version of the property.Opera: This value is only supported with the prefixed version of the property.Opera Android: This value is only supported with the prefixed version of the property.Samsung Internet: This value is only supported with the prefixed version of the property.WebView Android: This value is only supported with the prefixed version of the property.
css.properties.scroll-timeline.none 📋Safari9/15/2025185
css.properties.scroll-timeline-axis.block 📋Safari9/15/2025185
css.properties.scroll-timeline-axis.inline 📋Safari9/15/2025185
css.properties.scroll-timeline-axis.x 📋Safari9/15/2025185
css.properties.scroll-timeline-axis.y 📋Safari9/15/2025185
css.properties.scroll-timeline-name.none 📋Safari9/15/2025185
css.properties.shape-image-threshold.percentages Firefox10/22/20192340
css.properties.speak-as 📋Safari4/12/20182898
css.properties.speak-as.digits 📋Safari4/12/20182898
css.properties.speak-as.literal-punctuation 📋Safari4/12/20182898
css.properties.speak-as.no-punctuation 📋Safari4/12/20182898
css.properties.speak-as.normal 📋Safari4/12/20182898
css.properties.speak-as.spell-out 📋Safari4/12/20182898
css.properties.stroke-color 📋Safari4/12/20182898
css.properties.stroke-color.currentColor 📋Safari4/12/20182898
css.properties.stroke-color.transparent 📋Safari4/12/20182898
css.properties.text-align-last.match-parent 📋Safari9/12/20221284
css.properties.text-autospace.insert 📋Firefox11/11/2025128
css.properties.text-box 📋Safari12/11/2024463
css.properties.text-box.auto 📋Safari12/11/2024463
css.properties.text-box.cap 📋Safari12/11/2024463
css.properties.text-box.ex 📋Safari12/11/2024463
css.properties.text-box.ideographic 📋Safari12/11/2024463
css.properties.text-box.ideographic-ink 📋Safari12/11/2024463
css.properties.text-box.none 📋Safari12/11/2024463
css.properties.text-box.normal 📋Safari12/11/2024463
css.properties.text-box.text 📋Safari12/11/2024463
css.properties.text-box.trim-both 📋Safari12/11/2024463
css.properties.text-box.trim-end 📋Safari12/11/2024463
css.properties.text-box.trim-start 📋Safari12/11/2024463
css.properties.text-box-edge 📋Safari12/11/2024463
css.properties.text-box-edge.auto 📋Safari12/11/2024463
css.properties.text-box-edge.cap 📋Safari12/11/2024463
css.properties.text-box-edge.ex 📋Safari12/11/2024463
css.properties.text-box-edge.ideographic 📋Safari12/11/2024463
css.properties.text-box-edge.ideographic-ink 📋Safari12/11/2024463
css.properties.text-box-edge.text 📋Safari12/11/2024463
css.properties.text-box-trim 📋Safari12/11/2024463
css.properties.text-box-trim.none 📋Safari12/11/2024463
css.properties.text-box-trim.trim-both 📋Safari12/11/2024463
css.properties.text-box-trim.trim-end 📋Safari12/11/2024463
css.properties.text-box-trim.trim-start 📋Safari12/11/2024463
css.properties.text-decoration-inset 📋Firefox12/9/2025100
css.properties.text-decoration-inset.auto 📋Firefox12/9/2025100
css.properties.text-decoration-skip 📋Safari3/25/20192551
Chrome: Only supported the deprecated ink value.Chrome Android: Only supported the deprecated ink value.Opera: Only supported the deprecated ink value.Opera Android: Only supported the deprecated ink value.Samsung Internet: Only supported the deprecated ink value.WebView Android: Only supported the deprecated ink value.
css.properties.text-decoration-skip.auto 📋Safari10/22/20134531
css.properties.text-decoration-skip.none 📋Safari10/22/20134531
css.properties.text-emphasis-position.auto Firefox10/29/2024506
css.properties.text-justify 📋Firefox8/8/20173145
Edge: Standard values inter-character and none are supported. The deprecated distribute value is also supported.Internet Explorer: Standard values inter-character and none are supported. The deprecated distribute value is also supported.
css.properties.text-justify.auto 📋Firefox8/8/20173145
css.properties.text-justify.inter-character 📋Firefox8/8/20173145
css.properties.text-justify.inter-word 📋Firefox8/8/20173145
css.properties.text-justify.none 📋Firefox8/8/20173145
css.properties.text-overflow.string Firefox12/20/20115203
css.properties.text-overflow.two_value_syntax Firefox12/20/20115203
css.properties.text-transform.dutch_ij_digraph Firefox7/17/20124993
css.properties.text-transform.greek_accented_characters Firefox8/28/20124951
css.properties.text-transform.math-auto 📋Firefox8/29/2023933
css.properties.text-wrap.pretty 📋Safari9/15/2025185
css.properties.text-wrap-style.pretty 📋Safari9/15/2025185
css.properties.timeline-scope 📋Safari9/15/2025185
css.properties.timeline-scope.all 📋Safari9/15/2025185
css.properties.timeline-scope.none 📋Safari9/15/2025185
css.properties.transition-behavior.transitionable_content-visibility 📋Safari9/16/2024549
css.properties.transition-behavior.transitionable_display 📋Safari9/16/2024549
css.properties.user-modify Safari10/26/20076719
Firefox: While the CSS property is parsed and accepted, it does not have any effect.Firefox for Android: While the CSS property is parsed and accepted, it does not have any effect.
css.properties.user-modify.read-write-plaintext-only Safari10/26/20076719
css.properties.view-timeline.none 📋Safari9/15/2025185
css.properties.view-timeline-axis.block 📋Safari9/15/2025185
css.properties.view-timeline-axis.inline 📋Safari9/15/2025185
css.properties.view-timeline-axis.x 📋Safari9/15/2025185
css.properties.view-timeline-axis.y 📋Safari9/15/2025185
css.properties.view-timeline-inset 📋Safari9/15/2025185
css.properties.view-timeline-inset.auto 📋Safari9/15/2025185
css.properties.view-timeline-name.none 📋Safari9/15/2025185
css.properties.white-space.preserve-spaces 📋Firefox3/19/2024730
css.properties.white-space.shorthand_values Firefox3/19/2024730
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.Firefox: Only accepts values for white-space-collapse and text-wrap-mode, not white-space-trim.Firefox for Android: 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.white-space.svg_elements Firefox2/24/20154041
css.properties.white-space-collapse.preserve-spaces 📋Firefox3/19/2024730
css.properties.widows 📋Safari4/15/20057643
css.properties.width.fit-content_function 📋Firefox8/10/20211682
css.selectors.-moz-color-swatch Firefox2/4/20144426
css.selectors.-moz-first-node Firefox8/8/20173145
css.selectors.-moz-last-node Firefox8/8/20173145
css.selectors.-moz-list-bullet Firefox11/9/20047800
css.selectors.-moz-list-number Firefox11/9/20047800
css.selectors.-moz-only-whitespace Firefox11/9/20047800
css.selectors.-moz-progress-bar Firefox8/16/20115329
css.selectors.-moz-range-progress Firefox6/25/20134650
css.selectors.-moz-range-thumb Firefox5/14/20134692
css.selectors.-moz-range-track Firefox5/14/20134692
css.selectors.-moz-submit-invalid Firefox4/19/20211795
Firefox: From Firefox 88 the feature has been placed behind a flag. See bug 1694129.Firefox for Android: From version 88, the feature has been withdrawn. See bug 1694129.
css.selectors.-moz-window-inactive Firefox3/22/20115476
css.selectors.-webkit-inner-spin-button Safari6/7/20105764
css.selectors.-webkit-meter-bar Safari7/20/20115356
css.selectors.-webkit-meter-even-less-good-value Safari7/20/20115356
css.selectors.-webkit-meter-inner-element Safari10/22/20134531
css.selectors.-webkit-meter-optimum-value Safari7/20/20115356
css.selectors.-webkit-meter-suboptimum-value Safari7/20/20115356
css.selectors.-webkit-progress-bar Safari10/22/20134531
css.selectors.-webkit-progress-inner-element Safari10/22/20134531
css.selectors.-webkit-progress-value Safari10/22/20134531
css.selectors.-webkit-resizer Safari6/8/20096128
css.selectors.-webkit-scrollbar Safari6/8/20096128
Safari on iOS: From Safari 13, only display: none works with this pseudo-element. Other styles have no effect.WebView on iOS: From Safari 13, only display: none works with this pseudo-element. Other styles have no effect.
css.selectors.-webkit-scrollbar-button Safari6/8/20096128
css.selectors.-webkit-scrollbar-corner Safari6/8/20096128
css.selectors.-webkit-scrollbar-thumb Safari6/8/20096128
css.selectors.-webkit-scrollbar-track Safari6/8/20096128
css.selectors.-webkit-scrollbar-track-piece Safari6/8/20096128
css.selectors.-webkit-search-cancel-button Safari10/26/20076719
css.selectors.-webkit-search-results-button Safari10/26/20076719
css.selectors.-webkit-slider-runnable-track Safari9/16/2024549
css.selectors.-webkit-slider-thumb Safari9/16/2024549
css.selectors.after.nested_marker 📋Firefox9/16/2025184
css.selectors.attribute.case_sensitive_modifier Firefox3/19/20192557
css.selectors.before.nested_marker 📋Firefox9/16/2025184
css.selectors.buffering 📋Safari3/14/20221466
css.selectors.cue.selector_argument Safari10/22/20134531
css.selectors.first-child.no_parent_required Firefox3/7/20173299
css.selectors.first-letter.dutch_ij_digraph Firefox3/23/20211822
css.selectors.first-letter.svg_text_element Firefox3/19/2024730
css.selectors.first-line.svg_text_element Firefox3/19/2024730
css.selectors.fullscreen.all_elements Firefox12/15/20153747
css.selectors.future 📋Safari10/22/20134531
css.selectors.grammar-error 📋Safari3/5/2024744
css.selectors.has-slotted 📋Firefox3/4/2025380
css.selectors.last-child.no_parent_required Firefox3/7/20173299
css.selectors.left 📋Safari6/7/20105764
css.selectors.marker.counter_support 📋Firefox1/13/202665
css.selectors.marker.quotes_support 📋Firefox1/13/202665
css.selectors.muted 📋Safari3/14/20221466
css.selectors.nth-child.no_parent_required Firefox3/7/20173299
css.selectors.nth-last-child.no_parent_required Firefox3/7/20173299
css.selectors.open 📋Firefox3/4/2025380
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.past 📋Safari10/22/20134531
css.selectors.paused 📋Safari3/14/20221466
css.selectors.picture-in-picture 📋Safari3/24/20202186
css.selectors.playing 📋Safari3/14/20221466
css.selectors.right 📋Safari6/7/20105764
css.selectors.seeking 📋Safari3/14/20221466
css.selectors.spelling-error 📋Safari3/5/2024744
css.selectors.stalled 📋Safari3/14/20221466
css.selectors.volume-locked 📋Safari3/14/20221466
css.types.anchor-size.inset_margin Safari9/15/2025185
css.types.basic-shape.path.d 📋Firefox2/8/20221500
css.types.calc.typed_division_produces_unitless_number 📋Safari9/15/2025185
css.types.color.system-color.buttonborder 📋Firefox1/17/20231157
css.types.color.system-color.mark 📋Firefox1/17/20231157
css.types.color.system-color.marktext 📋Firefox1/17/20231157
css.types.image.cross-fade 📋Safari9/20/20163467
Chrome: Supports the original dual-image with percentage implementation only.Chrome: See bug 40470742 for supporting the unprefixed cross-fade() function.Chrome Android: Supports the original dual-image with percentage implementation only.Chrome Android: See bug 40470742 for supporting the unprefixed cross-fade() function.Edge: Supports the original dual-image with percentage implementation only.Edge: See bug 40470742 for supporting the unprefixed cross-fade() function.Quest Browser: Supports the original dual-image with percentage implementation only.Quest Browser: See bug 40470742 for supporting the unprefixed cross-fade() function.Opera: Supports the original dual-image with percentage implementation only.Opera: See bug 40470742 for supporting the unprefixed cross-fade() function.Opera Android: Supports the original dual-image with percentage implementation only.Opera Android: See bug 40470742 for supporting the unprefixed cross-fade() function.Safari: Supports the original dual-image with percentage implementation only.Safari: Supports the original dual-image with percentage implementation only.Safari on iOS: Support for the original dual-image with percentage implementation only.Safari on iOS: Supports the original dual-image with percentage implementation only.Samsung Internet: Supports the original dual-image with percentage implementation only.Samsung Internet: See bug 40470742 for supporting the unprefixed cross-fade() function.WebView Android: Supports the original dual-image with percentage implementation only.WebView Android: See bug 40470742 for supporting the unprefixed cross-fade() function.WebView on iOS: Support for the original dual-image with percentage implementation only.WebView on iOS: Supports the original dual-image with percentage implementation only.
css.types.image.element 📋Firefox11/14/20173047
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.image.filter 📋Safari3/21/20163650
css.types.progress 📋Safari9/15/2025185
css.types.random 📋Safari12/12/202597
css.types.random.dashed-ident 📋Safari12/12/202597
css.types.random.element-shared 📋Safari12/12/202597
css.types.random.step 📋Safari12/12/202597
css.types.ratio.number_value Firefox6/30/20202088
css.types.sibling-count 📋Safari12/12/202597
css.types.sibling-index 📋Safari12/12/202597
css.types.sign.typed_division_produces_unitless_number 📋Safari9/15/2025185
css.types.text-edge 📋Safari12/11/2024463
css.types.text-edge.alphabetic 📋Safari12/11/2024463
css.types.text-edge.cap 📋Safari12/11/2024463
css.types.text-edge.ex 📋Safari12/11/2024463
css.types.text-edge.text 📋Safari12/11/2024463