The tiny animation library - high performance, works with everthing from iOS to IE6, and dependency free. For applications where you need a lot of animation functionality without a lot of footprint.


A super lightweight, high performance, cross-browser, dependency-free animation library for the modern web.


  • Super lightweight: Just 3kb minified
  • High performance: Uses requestAnimationFrame and hardware-accelerated CSS transforms, degrades gracefully in older browsers
  • Cross browser: Tested in Chrome, Safari, Firefox, Opera, iOS, Android, and IE6+
  • Dependency-free: No jQuery, no MooTools, no YUI, no Closure
  • Supports module loaders: CommonJS and AMD


var fx = new Fx(DOMElement, property, options);
fx.get();       // get current value of the property 
fx.set(value);  // immediately set value 
fx.to(value);   // animate to value 


var element = document.getElementById('myElement');
var fx = new Fx(element, 'top', {
    duration: 1000


  • Fx.element {DOMElement} Returns the element attached to the Fx instance
  • Fx.property {String} Returns the property attached to the Fx instance
  • Fx.get() {Function} Returns the current value of the property attached to the Fx instance
  • Fx.set(value) {Function} Set the Fx instance's value immediately (without animating it)
  • Fx.to(value) {Function} Animate the Fx instance to the given value


  • duration {Number} The animation duration (in milliseconds)
  • animationStart {Function} Animation start hook
  • animationEnd {Function} Animation end hook
  • transition {Function} Custom relative transition function
  • unit {String} Units (px, %, em, deg, etc...)

##Supported properties

bottom height left margin margin-bottom margin-left margin-right margin-top opacity padding padding-bottom padding-left padding-right padding-top right scale scale3d top translate translate3d width zoom


background-color border-bottom-color border-color border-left-color border-right-color border-top-color color


scrollLeft scrollTop

##To do:

  • Unit tests
  • Support for transitioning multiple properties
  • Support for CSS class transitions
  • Support for colors