Web platform features explorer

The rcap CSS length unit is a font-relative length equal to the value of the cap unit on the root element. Cap-height is approximately equal to the height of a capital Latin letter.

Status

Baseline Newly Available (since 2026-01-13)

This feature is expected to reach Baseline Widely Available status on: 2028-07-13

MDN documentation

Rcap, in <length>

Specifications

CSS Values and Units Module Level 4 (#font-relative-lengths), from Cascading Style Sheets (CSS) Working Group (W3C).

Browser support

Chrome 118 Released on 2023-10-10
Chrome Android 118 Released on 2023-10-10
Edge 118 Released on 2023-10-13
Firefox 147 Released on 2026-01-13
Firefox for Android 147 Released on 2026-01-13
Safari 17.2 Released on 2023-12-11
Safari on iOS 17.2 Released on 2023-12-11

Usage (according to Chrome Platform Status)

~0.002% of page loads. More data at chromestatus.com.

Web Platform Tests (WPT)

View the latest WPT test results for this feature

Developer signals

Votes: 1

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