You are here: Home > Resources >

What is ALAC

What Is ALAC

ALAC stands for Apple Lossless Audio Codec(also known as Apple Lossless Encoder, ALE) is an audio codec developed for lossless data compression of digital music.


Apple Lossless data is stored within an MP4 container with the filename extension .m4a. It is not a variant of AAC (which is a lossy format), but a distinct lossless format that uses linear prediction similar to other lossless codecs such as FLAC and Shorten. All current iPod players can play Apple Lossless-encoded files. It does not use any digital rights management (DRM) scheme, but by the nature of the container, it is thought that DRM could be applied to ALAC much the same way it can with other files in QuickTime containers.


Apple claims that audio files compressed with its lossless codec will use up "about half the storage space" that the uncompressed data would require. Testers using a selection of music have found that compressed files are about 40% to 60% the size of the originals depending on the kind of music, similar to other lossless formats. Furthermore, the speed at which it can be decoded makes it useful for a limited-power device such as the iPod.

The Apple Lossless Encoder was introduced as a component of QuickTime 6.5.1 on April 28, 2004 and thus as a feature of iTunes 4.5 and above. The codec is also used in the AirPort Express's AirPlay implementation.

ALAC Related Articles


How to play ALAC?
How to join ALAC files
How to split ALAC files


ALAC Related Software


iPad Video Converter

iPhone Video Converter

Hot Topics

Top Search

3GP DVD Movie to iPad WMV Convert Videos to iPad rip DVD to iPhone 4 FLV MOV MP4 MPEG MOD TOD MKV SWF XVID DIVX VOB M2TS AVI MTS BDMV AVHCD DV M4V H.264 YouTube MOV to iPad