• 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 Firefox

The following features are only implemented in Firefox.

• Alternative style sheets

  Limited availability

  The rel="alternate stylesheet" attribute for the <link> HTML element offers an alternative style option to users.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox 3 Released on 2008-06-17
  • Firefox for Android 4 Released on 2011-03-29
  • Safari ❌
  • Safari on iOS ❌

• autocorrect

  Limited availability

  The autocorrect global HTML attribute controls whether to automatically correct spelling or punctuation errors for user input.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox 136 Released on 2025-03-04
  • Firefox for Android 136 Released on 2025-03-04
  • Safari ❌
  • Safari on iOS ❌

• Case-sensitive attribute selector

  Limited availability

  The s identifier in a CSS attribute selector matches attribute values case-sensitively in document languages like HTML where attribute values are case-insensitive.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox 66 Released on 2019-03-19
  • Firefox for Android 66 Released on 2019-03-19
  • Safari ❌
  • Safari on iOS ❌

• Reversed counter-reset

  Limited availability

  The reversed() CSS function for counter-reset creates a counter that counts down.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox 96 Released on 2022-01-11
  • Firefox for Android 96 Released on 2022-01-11
  • Safari ❌
  • Safari on iOS ❌

• Custom ellipses

  Limited availability

  The text-overflow CSS property with a string value sets the string representing clipped text.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox 9 Released on 2011-12-20
  • Firefox for Android 9 Released on 2011-12-21
  • Safari ❌
  • Safari on iOS ❌

• display: ruby

  Limited availability

  The display: ruby CSS declaration renders an element with the box layout of a <ruby> HTML element. Child elements may use equivalents to <ruby> internal elements such as display: ruby-base for <rb>.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox 88 Released on 2021-04-19
  • Firefox for Android 88 Released on 2021-04-19
  • Safari ❌
  • Safari on iOS ❌

• Early data

  Limited availability

  TLS 1.3 sessions may be resumed more quickly by sending so-called early data to servers before the TLS handshake has finished. Also known as zero round-trip time resumption or 0-RTT.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox 58 Released on 2018-01-23
  • Firefox for Android 58 Released on 2018-01-22
  • Safari ❌
  • Safari on iOS ❌

• font-language-override

  Limited availability

  The font-language-override CSS property sets which language-specific glyphs are displayed.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox 34 Released on 2014-12-01
  • Firefox for Android 34 Released on 2014-12-01
  • Safari ❌ Vendor position : unknown
  • Safari on iOS ❌ Vendor position : unknown

• font-synthesis-position

  Limited availability

  The font-synthesis-position CSS property sets whether or not the browser should synthesize subscript and superscript typefaces when they're missing from the font.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox 118 Released on 2023-09-26
  • Firefox for Android 118 Released on 2023-09-26
  • Safari ❌
  • Safari on iOS ❌

• Gamepad VR hands and poses

  Limited availability

  The hand and pose properties of a Gamepad object represent the position in space and the hand that WebVR controllers are held in.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox 55 Released on 2017-08-08
  • Firefox for Android 55 Released on 2017-08-08
  • Safari ❌ Vendor position : support (concerns: integration)
  • Safari on iOS ❌ Vendor position : support (concerns: integration)

• Map getOrInsert()

  Limited availability

  The getOrInsert() and getOrInsertComputed() methods of Map objects get a value, setting and getting a default value if needed.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox 144 Released on 2025-10-14
  • Firefox for Android 144 Released on 2025-10-14
  • Safari ❌
  • Safari on iOS ❌

• Global privacy control

  Limited availability

  The Sec-GPC request header indicates that the user does not consent to a website or service selling or sharing their personal information with third parties.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox 120 Released on 2023-11-21
  • Firefox for Android 122 Released on 2024-01-23
  • Safari ❌
  • Safari on iOS ❌

• ime-mode

  Discouraged

  The ime-mode CSS property sets the state of the input method editor for text fields.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox 3 Released on 2008-06-17
  • Firefox for Android 4 Released on 2011-03-29
  • Safari ❌
  • Safari on iOS ❌

• Math.sumPrecise()

  Limited availability

  The Math.sumPrecise() static method returns the sum of an iterable of numbers. It avoids the precision loss of intermediate partial sums, as found using reduce() or a loop to add together an array of values.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox 137 Released on 2025-04-01
  • Firefox for Android 137 Released on 2025-04-01
  • Safari ❌
  • Safari on iOS ❌

• ReadableStream.from()

  Limited availability

  The ReadableStream.from() static method converts an iterable or async iterable object, such as an array or async generator function, into a readable stream.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox 117 Released on 2023-08-29
  • Firefox for Android 117 Released on 2023-08-29
  • Safari ❌
  • Safari on iOS ❌

• image-rendering: smooth

  Limited availability

  The image-rendering: smooth CSS declaration scales images while retaining a gradual color blending that is useful for photos.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox 93 Released on 2021-10-05
  • Firefox for Android 93 Released on 2021-10-05
  • Safari ❌
  • Safari on iOS ❌

• Temporal

  Limited availability

  The Temporal API allows you to work with dates, times, time zones, and durations. It is more powerful than the Date API.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox 139 Released on 2025-05-27
  • Firefox for Android 139 Released on 2025-05-27
  • Safari ❌
  • Safari on iOS ❌

• text-justify

  Limited availability

  The text-justify CSS property sets the justification method of text when text-align: justify is set.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox 55 Released on 2017-08-08
  • Firefox for Android 55 Released on 2017-08-08
  • Safari ❌
  • Safari on iOS ❌

• video-dynamic-range media query

  Limited availability

  The video-dynamic-range CSS media query sets styles based on whether a device can display video with at least standard range colors or at least high range colors. Non-visual devices will match neither.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox 100 Released on 2022-05-03
  • Firefox for Android 100 Released on 2022-05-03
  • Safari ❌
  • Safari on iOS ❌

• WebDriver

  Limited availability

  The WebDriver protocol allows out-of-process programs to inspect and control browsers to, for example, run tests of web applications. Also known as WebDriver classic.

  Learn more

  • Chrome ❌
  • Chrome Android ❌
  • Edge ❌
  • Firefox 66 Released on 2019-03-19
  • Firefox for Android ❌
  • Safari ❌
  • Safari on iOS ❌