Keyframes allows dynamic generation of CSS3 keyframes with callback events and other niceness.

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Keyframes allows dynamic generation of CSS keyframes with callback events and other niceness.


CSS3 introduced fancy features like transformations, translations, rotations and scaling. Keyframes allows you to manage and execute animations using Javascript.


Install from npm:
npm install @keyframes/core --save

Import into your project using the following line:
import Keyframes from '@keyframes/core';

Be sure to define and play animations after the page has loaded by including your script tag at the bottom of the document or using window.onload.


Detecting CSS animation support
var supportedFlag = Keyframes.isSupported();


Defining keyframes happens before any any animation logic takes place. The CSS is stored and indexed in a single style tag in the header with the id keyframesjs-stylesheet.
Adding a new animation sequence (keyframe)
    name: 'trapdoor-sequence',
    '0%': {height: 70},
    '30%': {height: 10},
    '60%': {height: 30},
    '100%': {height: 10}

Adding a single frame style
    name: 'ball-roll',
    from: {
        transform: 'rotate(0deg)'
    to: {
        transform: 'rotate(360deg)'

Adding multiple frame styles
	name: 'roll-clockwise',
	'0%': {
	    marginLeft: 0,
	    backgroundColor: 'red',
	    transform: 'rotate(0deg)'
	'100%': {
	    marginLeft: 600,
	    transform: 'rotate(360deg)'
	name: 'roll-anti-clockwise',
	'0%': {
	    marginLeft: 0,
	    backgroundColor: 'red',
	    transform: 'rotate(0deg)'
	'100%': {
	    marginLeft: 600,
	    transform: 'rotate(-360deg)'

Adding styles and properties in array fashion
Gives resemblance to CSS styling definitions
var shake_start = {transform: 'translate(0px)'};
var shake_odd1 = {transform: 'translate(-10px, -10px)'};
var shake_even1 = {transform: 'translate(10px, 10px)'};
var shake_odd2 = {transform: 'translate(10px, -10px)'};
var shake_even2 = {transform: 'translate(-10px, 10px)'};

	name: 'crazy',
	'0%': shake_start,
	'10%': shake_odd2,
	'20%': shake_even1,
	'30%': shake_odd2,
	'40%': shake_even2,
	'50%': shake_odd2,
	'60%': shake_even1,
	'70%': shake_odd1,
	'80%': shake_even2,
	'90%': shake_odd1

Please note, you can add as many properties to the array as you want to
Responsive animations
    name: 'roll-clockwise',
    media: 'screen and (max-width: 700px)',
    from: {
        marginLeft: 0
    to: {
        marginLeft: 600


After the keyframes have been defined (see above), they can now be used on any element in the dom. First we must create an instance of Keyframejs using our chosen element.
const ball = new Keyframes(document.getElementById('ball'));

The css3 animation methods available are better documented here: http://www.w3schools.com/css/css3animations.asp
    name: 'trapdoor-sequence', // [required] name of the keyframe you want to bind to the selected element
    duration: '1s', // [optional, default: '0s'] how long you want it to last in milliseconds
    timingFunction: 'linear', // [optional, default: 'ease'] specifies the speed curve of the animation
    delay: '0s', //[optional, default: '0s']  how long you want to wait before the animation starts
    iterationCount: 'infinite', //[optional, default: 1]  how many times you want the animation to repeat
    direction: 'normal', //[optional, default: 'normal']  which direction you want the frames to flow
    fillMode: 'forwards', //[optional, default: 'forward']  how to apply the styles outside the animation time, default value is forwards
{ // Callbacks
    onBeforeStart, // Optional: Fired before the animation starts.
    onStart, // Optional: Fired after the animation started.
    onIteration, // Optional: If your animation has multiple iterations, this function will fire after each one.
    onEnd, // Optional: Fired at the end of the animation but if using a `queue`, it will fire after the queue has completed.

Playing an animation (shorthand)
    'trapdoor-sequence 1s linear 0s infinite normal forwards',

Playing multiple animations simultaneously (at the same time)
    'trapdoor-sequence 1s linear 0s infinite',
      name: 'ball-roll',
      duration: "3s",
      timingFunction: 'ease',
      iterationCount: 1
], callbacks);

Playing multiple animations sequentially on a loop
    'trapdoor-sequence 1s',
    ['crazy 2s', 'crazy-alt 2s'], // These animations are played simultaneously.
], callbacks);

Use a queue which can be added to whenever If the queue was previously empty, the queue will start executing immediately.
ball.queue('trapdoor-sequence 1s', callbacks) // Setting callbacks overrides previous callbacks so you only need to set it on the first call.
    .queue('crazy 3s'); // Run crazy after the trapdoor-sequence is complete.
setTimeout(() => ball.queue('crazy 3s'), 1000); // Add crazy to the queue again, so it will be run twice.

Reset the animation Resets styling, animations and removes callbacks.

Reset the queue Resets styling, animations, removes callbacks and clears the queue.

Pause keyframe animation

Resume keyframe animation

Want more control?

Handy functions to let you handle the styling yourself...
Generate the defined keyframes css
let css = Keyframes.defineCSS({
    name: 'ball-spin',
    from: {
        transform: 'rotate(90deg)',
    to: {
        transform: 'rotate(450deg)',
}); // "@keyframes ball-spin {from {transform:rotate(90deg);}to {transform:rotate(450deg);}"

Generate the "animation" rule's value (play)
const css = Keyframes.playCSS({
    name: 'ball-spin',
    duration: '1s',
    iterationCount: 1
}); // "ball-spin 1s ease 0s 1 normal forwards"


Installing a plugin is simple...
import Pathfinder from '@keyframes/pathfinder';
Keyframes.plugin(Pathfinder); // You can also pass an array of plugins for convenience.

See other plugins that allow for spritesheets & more complex movement paths: https://github.com/Keyframes


  • Deprecate chain
  • Fixed a bug where queue would not actually queue animations

  • Added loop method
  • Bug fixes
  • Added freeze and unfreeze

  • https://github.com/Keyframes/Keyframes/issues/1 Queue
  • https://github.com/Keyframes/Keyframes/issues/9 Js Style keys

  • Reset now uses requestAnimationFrame instead of timeouts.
  • Allow an array of plugins to be added
  • Code reduction.

  • Use insertRule to add keyframes to a single style tag in the header.

  • Add playCSS and defineCSS generation functions

  • Make it a module
  • Add plugin function

  • Vanilla project initiated