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Keyframe Formats

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.

Element.animate(), KeyframeEffectReadOnly.KeyframeEffectReadOnly(), KeyframeEffect.KeyframeEffect(), KeyframeEffect.setKeyframes() and SharedKeyframeList.SharedKeyframeList() all accept objects formatted to represent a set of keyframes. There are several options to this format, which are explained below.

Syntax

There are two different ways to format keyframes:

  1. An object containing key-value pairs consisting of the property to animate and an array of values to iterate over.

    element.animate({
      opacity: [ 0, 1 ],          // [ from, to ]
      color:   [ "#fff", "#000" ] // [ from, to ]
    }, 2000);
    
  2. An array of objects (keyframes) consisting of properties and values to iterate over. This is the canonical format returned by the getKeyframes() method.

    element.animate([ 
      { // from
        opacity: 0,
        color: "#fff"
      }, 
      { // to
        opacity: 1,
     ​   color: "#000"
      }
    ], 2000);

    With this latter form it is also possible to specify offsets for each keyframe by providing an offset value.

    element.animate([ { opacity: 1 },
                      { opacity: 0.1, offset: 0.7 },
                      { opacity: 0 } ],
                    2000);
    

    Note: offset values, if provided, must be between 0.0 and 1.0 and arranged in ascending order.

    Furthermore, using this form it is also possible to specify easing to apply between keyframes by providing an easing value as illustrated below.

    element.animate([ { opacity: 1, easing: 'ease-out' },
                      { opacity: 0.1, easing: 'ease-in' },
                      { opacity: 0 } ],
                    2000);
    

    In this example, the specified easing only applies from the keyframe where it is specified until the next keyframe. Any easing value specified on the options argument, however, applies across a single iteration of the animation — for the entire duration.

Specifications

Specification Status Comment
Web Animations
The definition of 'Keyframe object formats' in that specification.
Working Draft Initial definition

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support No support (Yes) No support No support 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