A library to work with CSS3 keyframe animations from javascript
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Create, Modify, and Remove CSS3 Keyframe Animations with javascript!

This library uses the CSS DOM API to access CSS3 keyframe animations, enabling you to do anything you want with them from javascript.

You can add, modify, and remove individual keyframes from existing animations, in addition to creating and deleting animations themselves.



Download css-animations.js to your project and load it. It works as an AMD module as well as a global object.

If not using it as an AMD module, it exports a global objects named CSSAnimations that allows you to access the API.

NOTE: This library searches all your stylesheets immediately when it is loaded. This will cause problems if you are somehow dynamically loading stylesheets after js is loaded (problems being missing animations). If this is common, I will change this library.

Browser Support

This is a new library and hasn't been extensively tested. It has only been tested in Firefox 17+ and Chrome 23+. It should work in browsers that implement unprefixed CSS3 animations and webkit (special prefixing has only been applied to webkit as it is not unprefixed yet).



  • CSSAnimations.get(name): return a KeyframeAnimation object representing the animation named name

  • CSSAnimations.create(name, frames): create a new animation named name and return the newly constructed KeyframeAnimation object. If frames is suppled, add them to the new animation with setKeyframes (see below). name is optional; if not specified a random name is generated. frames is also optional.

    // Create with name and keyframes
    var anim = CSSAnimations.create('foo', {
        '0%': { 'background-color': 'red' },
        '100%': { 'background-color': 'blue' }
    // Create with keyframes, names is randomly generated
    var anim = CSSAnimations.create({
        '0%': { 'background-color': 'red' },
        '100%': { 'background-color': 'blue' }
    // Create with just name and no keyframes
    var anim = CSSAnimations.create('foo');
    // Create with random name and no keyframes
    var anim = CSSAnimations.create();
  • CSSAnimations.remove(name): remove the animation named name. name can also be an instance of KeyframeAnimation. Right now, you can only remove animations created with CSSAnimations.create.


The KeyframeAnimation object represents a CSS3 animation.

  • KeyframeAnimation.getKeyframe(text): return a KeyframeRule object representing the animation at the specified keyframe. text is a string that represents the keyframe, such as "10%".

    var rule = anim.getKeyframe('10%');
  • KeyframeAnimation.setKeyframe(text, css): set the CSS for a specified keyframe. text is a string the represents the keyframes, like "10%", and css is a javascript object with key/values representing the CSS to set. It returns the same KeyframeAnimation object so you can chain it.

    anim.setKeyframe('10%': { 'background-color': '#333333' });
  • KeyframeAnimation.setKeyframes(frames): Same as setKeyframe, but sets multiple keyframes at once. frames is an object with the percentage values, like 10%, as keys and css as values.

        '10%': { 'background-color': '#333333' },
        '20%': { 'background-color': '#666666' },
  • KeyframeAnimation.clear(): Remove all keyframes from this animation.

  • KeyframeAnimation.getKeyframeTexts(): Get all the texts representing the keyframe positions, like "10%" and "100%".


The KeyframeRule object represents a specific animation keyframe.

  • KeyframeRule.keyText: the text representing the keyframe position, like "10%"

  • KeyframeRule.css: a javascript object representing the CSS for this keyframe

NOTE: In several places we represent CSS as javascript objects, but it does not transform property names to camelCase formatting. The keys in the object are the raw CSS properties and you'll most likely have to quote them because they contain dashed. For example, css = { 'background-color': 'red' } and css['background-color'].


// Changing an animation

var anim = CSSAnimations.get('pulse');
anim.setKeyframe('100%', { 'background-color': 'red' });

// Dynamically creating and applying an animation

var anim = CSSAnimations.create({
    '0%': { transform: 'translateY(0)' },
    '70%': { transform: 'translateY(50px)' },
    '100%': { transform: 'translateY(150px)' }

$(el).css({ 'animation-name': anim.name,
            'animation-duration': '1s' });

$(el).on('animationend', function() {

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