mask-origin

Baseline 2023

Newly available

Since December 2023, this feature works across the latest devices and browser versions. This feature might not work in older devices or browsers.

The mask-origin CSS property sets the origin of a mask.

For elements rendered as a single box, this property specifies the mask positioning area. In other words, this property specifies the origin position of an image specified by the mask-image CSS property. For elements rendered as multiple boxes, such as inline boxes on several lines or boxes on several pages, it specifies which boxes box-decoration-break operates upon to determine the mask positioning area.

Syntax

/* Keyword values */
mask-origin: content-box;
mask-origin: padding-box;
mask-origin: border-box;
mask-origin: fill-box;
mask-origin: stroke-box;
mask-origin: view-box;

/* Multiple values */
mask-origin: padding-box, content-box;
mask-origin: view-box, fill-box, border-box;

/* Non-standard keyword values */
-webkit-mask-origin: content;
-webkit-mask-origin: padding;
-webkit-mask-origin: border;

/* Global values */
mask-origin: inherit;
mask-origin: initial;
mask-origin: revert;
mask-origin: revert-layer;
mask-origin: unset;

One or more of the keyword values listed below, separated by commas.

Values

content-box: The position is relative to the content box.
padding-box: The position is relative to the padding box. For single boxes 0 0 is the upper left corner of the padding edge, 100% 100% is the lower right corner.
border-box: The position is relative to the border box.
fill-box: The position is relative to the object bounding box.
stroke-box: The position is relative to the stroke bounding box.
view-box: Uses the nearest SVG viewport as reference box. If a viewBox attribute is specified for the element creating the SVG viewport, the reference box is positioned at the origin of the coordinate system established by the viewBox attribute and the dimension of the reference box is set to the width and height values of the viewBox attribute.
content: Same as content-box.
padding: Same as padding-box.
border: Same as border-box.

Formal definition

Initial value	`border-box`
Applies to	all elements; In SVG, it applies to container elements excluding the `<defs>` element and all graphics elements
Inherited	no
Computed value	as specified
Animation type	discrete

Formal syntax

mask-origin = 
  <coord-box>#  

<coord-box> = 
  <paint-box>  |
  view-box     

<paint-box> = 
  <visual-box>  |
  fill-box      |
  stroke-box    

<visual-box> = 
  content-box  |
  padding-box  |
  border-box

Examples

Setting mask origin to border-box

Click "Play" in the live sample to open the code in the MDN Playground and try some of the other possible mask-origin values.

<div class="masked"></div>

.masked {
  width: 100px;
  height: 100px;
  margin: 10px;
  border: 10px solid blue;
  background-color: #8cffa0;
  padding: 10px;

  mask-image: url(https://mdn.github.io/shared-assets/images/examples/mask-star.svg);
  mask-origin: border-box;
}

Specifications

Specification
CSS Masking Module Level 1 # the-mask-origin

Browser compatibility

	Desktop					Mobile
	Chrome	Edge	Firefox	Opera	Safari	Chrome Android	Firefox for Android	Opera Android	Safari on IOS	Samsung Internet	WebView Android
`mask-origin`	1201	12079	53	10615	15.44	12018	53	8014	15.43.2	25.01.0	2
`border`	1	79	No	15	15.44	18	No	14	15.43.2	1.0	2
`content`	1	79	No	15	15.44	18	No	14	15.43.2	1.0	2
`fill-box`	120	120	53	106	No	120	53	80	No	25.0	120
`padding`	1	79	No	15	15.44	18	No	14	15.43.2	1.0	2
`stroke-box`	120	120	53	106	No	120	53	80	No	25.0	120
`view-box`	120	120	53	106	No	120	53	80	No	25.0	120