CSS -webkit-mask-origin Property Reference

The CSS -webkit-mask-origin property is a nonstandard property in WebKit Extensions. Review its formal syntax, computed behavior, and practical declarations.

Updated 2026-08-12

-webkit-mask-origin overview

The CSS -webkit-mask-origin property is a nonstandard property in WebKit Extensions. Review its formal syntax, computed behavior, and practical declarations.

The property is not inherited by default. Use an explicit global keyword when inheritance is intended.

Syntax and formal definition

-webkit-mask-origin formal syntax

Field	Value
Formal syntax	[ <coord-box> \| border \| padding \| content ]#
Initial value	padding
Applies to	allElements
Inherited	No
Percentages	no
Computed value	asSpecified
Animation type	discrete
Media	visual
Specification group	WebKit Extensions
Status	Nonstandard

Practical examples

These declarations demonstrate valid ways to set -webkit-mask-origin. The initial and inherit global keywords remain available even when a property-specific value is preferable.

-webkit-mask-origin live example

CSS

.reset-example {
  -webkit-mask-origin: initial;
}

.inherit-example {
  -webkit-mask-origin: inherit;
}

@supports (-webkit-mask-origin: initial) {
  .supported {
    -webkit-mask-origin: initial;
  }
}