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

The read-only Animation.ready property of the Web Animations API returns a Promise which resolves when the animation is ready to play. A new promise is created every time the animation enters the "pending" play state as well as when the animation is canceled, since in both of those scenarios, the animation is ready to be started again.

Since the same Promise is used for both pending play and pending pause requests, authors are advised to check the state of the animation when the promise is resolved.


var readyPromise = Animation.ready;


A Promise which resolves when the animation is ready to be played. You'll typically use a construct similar to this when using the ready promise:

animation.ready.then(function() {
  // Do whatever needs to be done when
  // the animation is ready to run


In the following example, the state of the animation will be running when the current ready Promise is resolved because the animation does not leave the pending play state in between the calls to pause and play and hence the current ready Promise does not change.

animation.ready.then(function() {
  // Displays 'running'


Specification Status Comment
Web Animations
The definition of 'Animation.ready' in that specification.
Working Draft Editor's draft.

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support No ?371 No No No
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support No No ?371 No No No

1. From version 37: 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.

See also

Document Tags and Contributors

Contributors to this page: fscholz, Sheppy, birtles, chrisdavidmills, rachelnabors
Last updated by: fscholz,