Animation: playbackRate property

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.


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.

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


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


const shrinkAlice = () => {
  aliceChange.playbackRate = -1;;

// 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:


const growAlice = () => {
  aliceChange.playbackRate = 1;;

// 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(() => {
  // Make sure the playback rate never falls below .4

  if (redQueen_alice.playbackRate > 0.4) {
    redQueen_alice.playbackRate *= 0.9;
}, 3000);

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


const goFaster = () => {
  redQueen_alice.playbackRate *= 1.1;

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


Web Animations
# dom-animation-playbackrate

Browser compatibility

BCD tables only load in the browser

See also