Web platform features explorer - Registered custom properties

Web platform features explorer

Tags: api css

The CSS.registerProperty() static method and the @property CSS at-rule register custom properties for which types and behaviors can be defined.

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Specifications

CSS Properties and Values API Level 1, from Cascading Style Sheets (CSS) Working Group (W3C).

Browser support

Chrome 85 Released on 2020-08-25
Chrome Android 85 Released on 2020-08-25
Edge 85 Released on 2020-08-27
Firefox 128 Released on 2024-07-09
Firefox for Android 128 Released on 2024-07-09
Safari 16.4 Released on 2023-03-27
Safari on iOS 16.4 Released on 2023-03-27

Developer signals

State of CSS 2025: features/all_features question
State of CSS 2024: reading_list/reading_list question
State of CSS 2024: features/all_features question

Usage (according to Chrome Platform Status)

~3.600% of page loads. More data at chromestatus.

Interop

Included in Interop 2023
Included in Interop 2024

Web Platform Tests (WPT)

View the latest WPT test results for this feature

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