Web/API/KeyframeEffect/KeyframeEffect

This is an experimental technologyCheck the Browser compatibility table carefully before using this in production.

The KeyframeEffect() constructor of the Web Animations API returns a new KeyframeEffect object instance, and also allows you to clone an existing keyframe effect object instance.

Syntax

var keyframes = new KeyframeEffect(element, keyframeSet, keyframeOptions);
var keyframes = new KeyframeEffect(sourceKeyFrames);

Parameters

The first type of constructor (see above) creates a completely new KeyframeEffect object instance. Its parameters are:

element

The DOM element to be animated, or null.

keyframeSet

An keyframe object or null.

keyframeOptions Optional

Either an integer representing the animation's duration (in milliseconds), or an Object containing one or more of the following:

delay Optional: The number of milliseconds to delay the start of the animation. Defaults to 0.
direction Optional: Whether the animation runs forwards (normal), backwards (reverse), switches direction after each iteration (alternate), or runs backwards and switches direction after each iteration (alternate-reverse). Defaults to "normal".
duration Optional: The number of milliseconds each iteration of the animation takes to complete. Defaults to 0. Although this is technically optional, keep in mind that your animation will not run if this value is 0.
easing Optional: The rate of the animation's change over time. Accepts the pre-defined values "linear", "ease", "ease-in", "ease-out", and "ease-in-out", or a custom "cubic-bezier" value like "cubic-bezier(0.42, 0, 0.58, 1)". Defaults to "linear".
endDelay Optional: The number of milliseconds to delay after the end of an animation. This is primarily of use when sequencing animations based on the end time of another animation. Defaults to 0.
fill Optional: Dictates whether the animation's effects should be reflected by the element(s) prior to playing ("backwards"), retained after the animation has completed playing ("forwards"), or both. Defaults to "none".
iterationStart Optional: Describes at what point in the iteration the animation should start. 0.5 would indicate starting halfway through the first iteration for example, and with this value set, an animation with 2 iterations would end halfway through a third iteration. Defaults to 0.0.
iterations Optional: The number of times the animation should repeat. Defaults to 1, and can also take a value of Infinity to make it repeat for as long as the element exists.

composite: Determines how values are combined between this animation and the element's underlying values.
iterationComposite: Determines how values build from iteration to iteration in the current animation.

The second type of constructor (see above) creates a clone of an existing KeyframeEffect object instance. Its parameter is as follows:

sourceKeyFrames: A KeyframeEffect object that you want to clone.

Examples

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
  );

Specifications

Specification	Status	Comment
Web Animations Level 2The definition of 'KeyframeEffectOptions.iterationComposite' in that specification.	Draft	Added the `iterationComposite` option.
Web AnimationsThe definition of 'keyframeEffect()' in that specification.	Working Draft	Editor's draft.

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`KeyframeEffect()` constructor Experimental'	Chrome Full support 75	Edge Full support 79	Firefox Full support 63	IE No support No	Opera Full support 62	Safari No support No	WebView Android Full support 75	Chrome Android Full support 75	Firefox Android Full support 63	Opera Android Full support 54	Safari iOS No support No	Samsung Internet Android Full support 11.0

Legend

Full support: Full support
No support: No support
Experimental. Expect behavior to change in the future.': Experimental. Expect behavior to change in the future.