The Apple Lossless Audio Codec (ALAC) is an audio codec developed by Apple and included in the original iPod. ALAC is a data compression method which reduces the size of audio files with no loss of information. A decoded ALAC stream is bit-for-bit identical to the original uncompressed audio file.

The original encoder and decoder were open sourced by Apple, and this is a port of the decoder to CoffeeScript so that ALAC files can be played in the browser.

You can check out a demo alongside our other decoders flac.js, MP3.js, and AAC.js. Currently, alac.js works properly in the latest versions of Firefox, Chrome, and Safari.

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

We use browserify to build alac.js. You can download a prebuilt version from the Github releases page. To build alac.js for the browser yourself, use the following commands:

npm install
make browser

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

alac.js depends on Aurora.js, our audio codec framework. For detailed information on how to use Aurora.js, check out the documentation.

alac.js is released under the same terms as the original ALAC decoder from Apple, which is the Apache 2 license.