This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the specification changes.

The duration property of AnimationEffectTimingReadOnly represents the duration in milliseconds to complete a single iteration of the animation.

Note: In AnimationEffectTiming, a mutable subclass of AnimationEffectTimingReadOnly used withKeyframeEffects, the property acts as both a getter and a setter.


// Getting the duration of each iteration
var animationLoopDuration = animation.effect.timing.duration;

// Setting the duration of each iteration
animation.effect.timing.duration = 5000;


The number of milliseconds each iteration of the animation takes to complete. Defaults to 0.

Note: In this level of this specification, the string value auto is equivalent to 0. This is a forwards-compatiblity measure since a future level of this specification will introduce group effects where the auto value expands to include the duration of the child effects.


In the Red Queen's Race example, we set the background's animation to begin halfway through its first loop:

var sceneryTimingBackground = {
  duration: 36000,
  iterations: Infinity

var sceneryTimingForeground = {
  duration: 12000,
  iterations: Infinity

var background1 = document.getElementById('background1');

// Animating the background
var background1Movement = background1.animate( sceneryFrames, sceneryTimingBackground );

// Setting the background animation's start position based on its duration
background1Movement.currentTime = background1Movement.effect.timing.duration / 2;


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

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support (Yes) 48 (48) No support (Yes) No support
Feature Android Android Webview Chrome for Android Firefox Mobile (Gecko) Firefox OS IE Mobile Opera Mobile Safari Mobile
Basic support ? ? ? ? ? No support No support No support

See also


© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.

Animation AnimationEffectTimingReadOnly API duration Experimental Property Reference waapi web animations api