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 composite property of a KeyframeEffectReadOnly or a KeyframeEffect resolves how an element's animation impacts its underlying property values. 

Note: For KeyframeEffect, this property is both a getter and a setter. For KeyframeEffectReadOnly, it is read-only.


// getting
var compositeEnumeration = keyframeEffect.composite;

// setting
keyframeEffect.composite = 'accumulate';


To understand these values, take the example of a keyframeEffect value of blur(2) working on an underlying property value of  blur(3).

The keyframeEffect overrides the underlying value it is combined with:  blur(2) replaces blur(3).
The keyframeEffect is added to the underlying value with which it is combined (aka additive):  blur(2) blur(3).
The keyframeEffect is accumulated on to the underlying value:  blur(5).


Specification Status Comment
Web Animations
The definition of 'keyframeEffectReadOnly.composite' in that specification.
Working Draft Editor's draft.

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support No support No support No support No support No support
Feature Android Android Webview Chrome for Android Firefox Mobile (Gecko) Firefox OS IE Mobile Opera Mobile Safari Mobile
Basic support ? ? ? ? ? ? ? ?

See also


© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.

Animation API composite Experimental KeyframeEffect KeyframeEffectReadOnly Property Reference waapi web animations api