Newly Available
Units
id: rex
rex unit
The
rex CSS length unit is a font-relative length that is equal to the x-height of the root element.
Baseline Status:
Achieved Newly Available on Jan 13, 2026 across core engines.
Desktop Browser Engine Support
Google Chrome
111
Supported
Mozilla Firefox
147
Supported
Apple Safari
17.2
Supported
Microsoft Edge
111
Supported
Mobile Browser Engine Support
Chrome Android
111
Firefox Android
147
Safari iOS
17.2
Specifications and References
MDN Browser Compat Data Keys: