• Filters:
• Newly available
• Widely available
• Limited availability
• One missing engine
• Discouraged
• All features

• Features only in:
• Chromium
• Firefox
• Safari

• Browser releases:
• Chrome
• Chrome Android
• Edge 141
• Firefox 144
• Firefox for Android 144
• Safari 26
• Safari on iOS 26

Features implemented only in Safari

The following features are only implemented in Safari.

• Audio session

  Limited availability

  The navigator.audioSession API controls how audio playback interacts with other applications. For example, playing music can pause audio from other applications, while ambient audio can play at the same time.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox ❌
  • Firefox for Android ❌
  • Safari 16.4 Released on 2023-03-27
  • Safari on iOS 16.4 Released on 2023-03-27

• Audio and video tracks

  Limited availability

  The audioTracks and videoTracks APIs for media elements switch audio and video tracks during playback.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox ❌
  • Firefox for Android ❌
  • Safari 8 Released on 2014-10-16
  • Safari on iOS 8 Released on 2014-09-17

• background-clip: border-area

  Limited availability

  The background-clip: border-area CSS declaration draws the background underneath only the border of an element.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox ❌
  • Firefox for Android ❌
  • Safari 18.2 Released on 2024-12-11
  • Safari on iOS 18.2 Released on 2024-12-11

• contrast-color()

  Limited availability

  The contrast-color() CSS function picks a color that has guaranteed contrast against a specified foreground or background color.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox ❌
  • Firefox for Android ❌
  • Safari 26 Released on 2025-09-15
  • Safari on iOS 26 Released on 2025-09-15

• cross-fade()

  Limited availability

  The cross-fade() CSS function generates an image by mixing two images.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox ❌ Vendor position : unknown
  • Firefox for Android ❌ Vendor position : unknown
  • Safari 10 Released on 2016-09-20
  • Safari on iOS 9.3 Released on 2016-03-21

• CSS object model (DOM level 2)

  Discouraged

  The DOM level 2 style specification defined interfaces to access and modify CSS styles, such as CSSValue and CSSPrimitiveValue, that were later excluded from the CSS object model.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox ❌
  • Firefox for Android ❌
  • Safari 10 Released on 2016-09-20
  • Safari on iOS 10 Released on 2016-09-13

• UI fonts

  Limited availability

  The ui-serif, ui-sans-serif, ui-monospace and ui-rounded values for the font-family CSS property use device-default user interface fonts for text.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox ❌
  • Firefox for Android ❌
  • Safari 13.1 Released on 2020-03-24
  • Safari on iOS 13.4 Released on 2020-03-24

• font-width

  Limited availability

  The font-width CSS property selects a font face from a font family based on width, either by a keyword such as condensed or a percentage.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox ❌
  • Firefox for Android ❌
  • Safari 18.4 Released on 2025-03-31
  • Safari on iOS ❌

• glyph-orientation-vertical

  Discouraged

  The glyph-orientation-vertical CSS property sets the orientation of glyphs in text rendered in a vertical writing mode.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox ❌
  • Firefox for Android ❌
  • Safari 4 Released on 2009-06-08
  • Safari on iOS 3.2 Released on 2010-04-03

• alpha and colorspace attributes for <input type=color>

  Limited availability

  The ability to control the opacity of a color picked using <input type="color"> and determine the colorspace of the selected color.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox ❌ Vendor position : positive
  • Firefox for Android ❌ Vendor position : positive
  • Safari 18.4 Released on 2025-03-31
  • Safari on iOS 18.4 Released on 2025-03-31

• Insertable streams for MediaStreamTrack

  Limited availability

  The MediaStreamTrackProcessor and MediaStreamTrackGenerator APIs modify the contents of a media track for merging streams, applying real-time effects like funny hats, and content overlays.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox ❌
  • Firefox for Android ❌
  • Safari 18 Released on 2024-09-16
  • Safari on iOS 18 Released on 2024-09-16

• inverted-colors media query

  Limited availability

  The inverted-colors CSS media query sets styles based on whether the user has inverted all colors, such as with mobile accessibility settings.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox ❌ Vendor position : unknown
  • Firefox for Android ❌ Vendor position : unknown
  • Safari 9.1 Released on 2016-03-21
  • Safari on iOS 10 Released on 2016-09-13

• JPEG XL

  Limited availability

  The JPEG XL image format is a raster graphics file format that supports animation, alpha transparency, and lossy as well as lossless compression.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox ❌ Vendor position : neutral
  • Firefox for Android ❌ Vendor position : neutral
  • Safari 17 Released on 2023-09-18
  • Safari on iOS 17 Released on 2023-09-18

• Managed media source

  Limited availability

  The ManagedMediaSource API is a MediaSource where the browser manages the memory of source buffers and may evict data if needed.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox ❌ Vendor position : positive
  • Firefox for Android ❌ Vendor position : positive
  • Safari 17 Released on 2023-09-18
  • Safari on iOS 17.1 Released on 2023-10-25

• margin-trim

  Limited availability

  The margin-trim CSS property removes the margins of child elements when they meet the edges of the container.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox ❌ Vendor position : positive
  • Firefox for Android ❌ Vendor position : positive
  • Safari 16.4 Released on 2023-03-27
  • Safari on iOS 16.4 Released on 2023-03-27

• mask-border

  Limited availability

  The mask-border CSS property sets how the edges of an element are masked. It is a shorthand for mask-border-outset, mask-border-repeat, mask-border-slice, mask-border-source, and mask-border-width.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox ❌
  • Firefox for Android ❌
  • Safari 17.2 Released on 2023-12-11
  • Safari on iOS 17.2 Released on 2023-12-11

• Media element pseudo-classes

  Limited availability

  The :playing, :paused, :seeking, :buffering, :stalled, :muted, and :volume-locked CSS pseudo-classes match <audio> and <video> elements based on their state.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox ❌
  • Firefox for Android ❌
  • Safari 15.4 Released on 2022-03-14
  • Safari on iOS 15.4 Released on 2022-03-14

• MediaController

  Discouraged

  The playback of multiple <video> or <audio> elements can be coordinated by a MediaController instance, for example to synchronize a sign-language interpreter track with the main video track.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox ❌
  • Firefox for Android ❌
  • Safari 7 Released on 2013-10-22
  • Safari on iOS 7 Released on 2013-09-18

• Private click measurement

  Limited availability

  The attributionsourceid and attributiondestination attributes for <a> elements measure clicks across websites without associating a click to a specific session. Not to be confused with attribution reporting. Also known as PCM.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox ❌ Vendor position : defer
  • Firefox for Android ❌ Vendor position : defer
  • Safari 15.4 Released on 2022-03-14
  • Safari on iOS 15.4 Released on 2022-03-14

• ruby-overhang

  Limited availability

  The ruby-overhang CSS property sets whether ruby annotations may overlap adjacent text.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox ❌
  • Firefox for Android ❌
  • Safari 18.2 Released on 2024-12-11
  • Safari on iOS 18.2 Released on 2024-12-11

• Scoped custom element registries

  Limited availability

  The CustomElementRegistry() constructor creates a new custom element registry that's separate from the global window.customElements registry. Creating more than one registry is useful for multiple custom elements that have the same tag name to coexist.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox ❌
  • Firefox for Android ❌
  • Safari 26 Released on 2025-09-15
  • Safari on iOS 26 Released on 2025-09-15

• speak-as

  Limited availability

  The speak-as CSS property sets how any element's content is spoken. Not to be confused with the speak-as descriptor of @counter-style at-rules.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox ❌
  • Firefox for Android ❌
  • Safari 11.1 Released on 2018-04-12
  • Safari on iOS 11.3 Released on 2018-03-29