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

css
/* 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 valueborder-box
Applies toall elements; In SVG, it applies to container elements excluding the <defs> element and all graphics elements
Inheritedno
Computed valueas specified
Animation typediscrete

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.

html
<div class="masked"></div>
css
.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

BCD tables only load in the browser

See also