This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
The KeyframeEffect()
constructor of the Web Animations API returns a new
object instance, and also allows you to clone an existing keyframe effect object instance.KeyframeEffect
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"
), orboth
. 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 ofInfinity
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 2 The definition of 'KeyframeEffectOptions.iterationComposite' in that specification. |
Draft | Added the iterationComposite option. |
Web Animations The definition of 'keyframeEffect()' in that specification. |
Working Draft | Editor's draft. |
Browser compatibility
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
KeyframeEffect() constructor | Chrome Full support Yes | Edge Full support ≤79 | Firefox Full support 63 | IE No support No | Opera No support No | Safari No support No | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android Full support 63 | Opera Android No support No | Safari iOS No support No | Samsung Internet Android Full support Yes |
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.