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Aurora.js is a framework that makes writing audio decoders in JavaScript easier. It handles common tasks for you such as dealing with binary data, and the decoding pipeline from source to demuxer to decoder, and finally to the audio hardware itself by abstracting browser audio APIs. Aurora contains two high level APIs for inspecting and playing back decoded audio, and it is easily extendible to support more sources, demuxers, decoders, and audio devices.

Check out the documentation to learn more about using and extending Aurora.


We have written several decoders using Aurora.js, whose demos you can find here and whose source code can be found on our Github page.


Aurora.js was written by @jensnockert and @devongovett of Audiocogs.


You can use Aurora.js both in the browser, as well as in Node.js. In the browser, you can either download a prebuilt release or use browserify to build it into your own app bundle (see below for Node.js usage - it's the same for browserify).

<script src="aurora.js"></script>
<script src="mp3.js"></script>
<!-- more codecs here -->

To use Aurora.js in Node.js or a browserify build, you can install it from npm:

npm install av

Then, require the module and codecs you need:

var AV = require('av');
// more codecs here...

For much more detailed information on how to use Aurora.js, check out the documentation.


We use browserify to build Aurora.js. To build Aurora.js for the browser yourself, use the following commands:

npm install
make browser

This will place a built aurora.js file, as well as a source map in the build/ directory.

By itself, Aurora will play LPCM, uLaw and aLaw files in a number of containers. Be sure to add additional codec support by including some of our other decoders:

If you want to build Aurora without the default codecs, you can use the "browser_slim" profile:

make browser_slim

This can help shave off approx. 30 KB from the joined file, or 20 KB when minified.


Aurora.js is released under the MIT license.