This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the specification changes.
The mask-composite CSS property represents a compositing operation used on the current mask layer with the mask layers below it.
/* Keyword values */ mask-composite: add; mask-composite: subtract; mask-composite: intersect; mask-composite: exclude; /* Global values */ mask-composite: inherit; mask-composite: initial; mask-composite: unset;
| Initial value | add |
|---|---|
| Applies to | all elements; In SVG, it applies to container elements excluding the <defs> element and all graphics elements |
| Inherited | no |
| Media | visual |
| Computed value | as specified |
| Animation type | discrete |
| Canonical order | the unique non-ambiguous order defined by the formal grammar |
Syntax
One or more of the keyword values listed below, separated by commas.
Values
For the composition the current mask layer is referred to as source, while all layers below it are referred to as destination.
add- The source is placed over the destination.
subtract- The source is placed, where it falls outside of the destination.
intersect- The parts of source that overlap the destination, replace the destination.
exclude- The non-overlapping regions of source and destination are combined.
Formal syntax
<compositing-operator>#where
<compositing-operator> = add | subtract | intersect | exclude
Example
CSS
#masked {
width: 100px;
height: 100px;
background-color: #8cffa0;
mask-image: url(https://mdn.mozillademos.org/files/12668/MDN.svg),
url(https://mdn.mozillademos.org/files/12676/star.svg);
mask-size: 100% 100%;
mask-composite: add; /* Can be changed in the live sample */
}
HTML
<div id="masked"> </div> <select id="compositeMode"> <option value="add">add</option> <option value="subtract">subtract</option> <option value="intersect">intersect</option> <option value="exclude">exclude</option> </select>
JavaScript
var clipBox = document.getElementById("compositeMode");
clipBox.addEventListener("change", function (evt) {
document.getElementById("masked").style.maskComposite = evt.target.value;
});
Specifications
| Specification | Status | Comment |
|---|---|---|
| CSS Masking Module Level 1 The definition of 'mask-composite' in that specification. |
Candidate Recommendation | Initial definition |
Browser compatibility
| Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
|---|---|---|---|---|---|
| Basic support | No support[1] | 53.0 (53.0) | No support | No support[1] | No support[1] |
| Feature | Android | Firefox Mobile (Gecko) | IE Phone | Opera Mobile | Safari Mobile |
|---|---|---|---|---|---|
| Basic support | ? | 53.0 (53.0) | No support | ? | ? |
[1] WebKit and Blink have a -webkit-mask-composite property, which has different keywords.