Web/API/Animation/playbackRate

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

The Animation.playbackRate property of the Web Animations API returns or sets the playback rate of the animation.

Animations have a playback rate that provides a scaling factor from the rate of change of the animation's timeline time values to the animation’s current time. The playback rate is initially 1.

Syntax

var currentPlaybackRate = Animation.playbackRate;

Animation.playbackRate = newRate;

Value

Takes a number that can be 0, negative, or positive. Negative values reverse the animation. The value is a scaling factor, so for example a value of 2 would double the playback rate.

Setting an animation’s playbackRate to 0 effectively pauses the animation (however, its playstate does not necessarily become paused).

Examples

In the Growing/Shrinking Alice Game example, clicking or tapping the bottle causes Alice's growing animation (aliceChange) to reverse, causing her to shrink:

var shrinkAlice = function() {
  aliceChange.playbackRate = -1;
  aliceChange.play();
}

// On tap or click, Alice will shrink.
bottle.addEventListener("mousedown", shrinkAlice, false);
bottle.addEventListener("touchstart", shrinkAlice, false);

Contrariwise, clicking on the cake causes her to "grow," playing aliceChange forwards again:

var growAlice = function() {
  aliceChange.playbackRate = 1;
  aliceChange.play();  
}

// On tap or click, Alice will grow.
cake.addEventListener("mousedown", growAlice, false);
cake.addEventListener("touchstart", growAlice, false);

In another example, the Red Queen's Race Game, Alice and the Red Queen are constantly slowing down:

setInterval( function() {

  // Make sure the playback rate never falls below .4

  if (redQueen_alice.playbackRate > .4) {
    redQueen_alice.playbackRate *= .9;    
  }

}, 3000);

But clicking or tapping on them causes them to speed up by multiplying their playbackRate:

var goFaster = function() {
  redQueen_alice.playbackRate *= 1.1;
}

document.addEventListener("click", goFaster);
document.addEventListener("touchstart", goFaster);

Specifications

Specification	Status	Comment
Web AnimationsThe definition of 'Animation.playbackRate' in that specification.	Working 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
`playbackRate` Experimental'	Chrome Full support 39	Edge Full support 79	Firefox Full support 48 Full support 48 No support 46 — 48 Disabled' Disabled' From version 46 until version 48 (exclusive): this feature is behind the `dom.animations-api.core.enabled` preference (needs to be set to `true`). To change preferences in Firefox, visit about:config.	IE No support No	Opera Full support 26	Safari No support No	WebView Android Full support 39	Chrome Android Full support 39	Firefox Android Full support 48 Full support 48 No support 46 — 48 Disabled' Disabled' From version 46 until version 48 (exclusive): this feature is behind the `dom.animations-api.core.enabled` preference (needs to be set to `true`). To change preferences in Firefox, visit about:config.	Opera Android Full support 26	Safari iOS No support No	Samsung Internet Android Full support 4.0

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.
User must explicitly enable this feature.': User must explicitly enable this feature.