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 KeyframeEffect interface of the Web Animations API lets us create sets of animatable properties and values, called keyframes. These can then be played using the Animation.Animation() constructor.


Returns a new KeyframeEffect object instance.


This interface inherits some of its methods and properties from its parent, KeyframeEffectReadOnly, and its grandparent AnimationEffectReadOnly.

The AnimationEffectTimingReadOnly object associated with the animation containing all the animation's timing values.
Gets and sets the element or pseudo-element being animated by this object. This may be null for animations that do not target a specific element.

Future properties

The following options are currently not shipped anywhere, but will be added in the near future.

Gets and sets the iteration composite operation for resolving the property value changes of this keyframe effect.
Gets and sets the composite operation property for resolving the property value changes between this and other keyframe effects.
Gets and sets the temporal spacing of the keyframe effect's iterations.


Returns the computed keyframes that make up this effect along with their computed keyframe offsets.
Replaces the set of keyframes that make up this effect.
Returns the calculated, current timing values for this keyframe effect.


In the Follow the White Rabbit example, the KeyframeEffect constructor is used to create a set of keyframes that dictate how the White Rabbit should animate down the hole:

 var rabbitDownKeyframes = new KeyframeEffect( 
    whiteRabbit, // element to animate
      { transform: 'translateY(0%)' }, // keyframe 
      { transform: 'translateY(100%)' } // keyframe
    { duration: 3000, fill: 'forwards' } // keyframe options


Specification Status Comment
Web Animations
The definition of 'keyframeEffect' 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 No support No support No support No support No support No support No support No support

See also


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

Animation API Experimental Interface KeyframeEffect Reference waapi web animations api