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Commit time
Nov 11, 2014
May 5, 2016
Jun 24, 2019

What is Web Animations?

A new JavaScript API for driving animated content on the web. By unifying the animation features of SVG and CSS, Web Animations unlocks features previously only usable declaratively, and exposes powerful, high-performance animation capabilities to developers.

What is in this repository?

A JavaScript implementation of the Web Animations API that provides Web Animation features in browsers that do not support it natively. The polyfill falls back to the native implementation when one is available.

Quick start

Here's a simple example of an animation that fades and scales a <div>.
Try it as a live demo.

<!-- Include the polyfill -->
<script src="web-animations.min.js"></script>

<!-- Set up a target to animate -->
<div class="pulse" style="width: 150px;">Hello world!</div>

<!-- Animate! -->
    var elem = document.querySelector('.pulse');
    var animation = elem.animate({
        opacity: [0.5, 1],
        transform: ['scale(0.5)', 'scale(1)'],
    }, {
        direction: 'alternate',
        duration: 500,
        iterations: Infinity,


We love feedback!

Keep up-to-date

Breaking polyfill changes will be announced on this low-volume mailing list:

More info