Web platform features explorer - Custom properties

Web platform features explorer

Custom properties are CSS properties prefixed with -- that set values you can reuse with the var() function. For example, you can set a --key-color property to reuse as border-color: var(--key-color). Also known as CSS variables.

Status

Baseline Widely Available (since 2019-10-05)

MDN documentation

Custom properties (--*): CSS variables

Specifications

CSS Custom Properties for Cascading Variables Module Level 1, from Cascading Style Sheets (CSS) Working Group (W3C).

Browser support (view on caniuse.com)

Chrome 49 Released on 2016-03-02
Chrome Android 49 Released on 2016-03-09
Edge 15 Released on 2017-04-05
Firefox 31 Released on 2014-07-22
Firefox for Android 31 Released on 2014-07-22
Safari 9.1 Released on 2016-03-21
Safari on iOS 9.3 Released on 2016-03-21

Web Platform Tests (WPT)

View the latest WPT test results for this feature

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