ALAC (Apple Lossless)
Also known as: Apple Lossless, ALAC file, Apple Lossless Audio Codec
ALAC (Apple Lossless Audio Codec) compresses audio with no loss of quality — it reproduces the original recording exactly while taking up less space than uncompressed PCM. Because nothing is discarded, ALAC files are much larger than lossy MP3 or AAC, typically several times the size.
- Lossless — exact copy of the original
- Much larger than MP3 or AAC
- Apple’s equivalent of FLAC
Lossless, not uncompressed
ALAC is lossless: it shrinks a file but can rebuild the original audio bit-for-bit, like zipping a document. That makes it roughly half the size of an uncompressed file, yet still far larger than a lossy MP3 or AAC of the same track.
For most listening on phones and earbuds, the audible difference from a good lossy file is negligible, but ALAC matters to people archiving music or editing audio who want a perfect master copy.
ALAC vs FLAC and storage
ALAC is Apple’s answer to FLAC; the two are technically similar lossless codecs, with ALAC preferred in the Apple ecosystem and FLAC more common elsewhere. ALAC usually lives in an `.m4a` or `.caf` file.
A lossless library eats storage fast. If space is tight on your device, converting archive copies to AAC or MP3 for everyday listening reclaims a large amount of room.