Animation: playbackRate property

Baseline 2022

Newly available

Since September 2022, this feature works across the latest devices and browser versions. This feature might not work in older devices or browsers.

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.

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.

Note: 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:

js
const shrinkAlice = () => {
  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:

js
const growAlice = () => {
  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:

js
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:

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

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

Specifications

Specification
Web Animations
# dom-animation-playbackrate

Browser compatibility

BCD tables only load in the browser

See also