ALAC (Apple Lossless Audio Codec)
Definition
A lossless audio compression codec developed by Apple. Reduces file size by approximately 40–60% without discarding any audio data. The decoded output is bit-identical to the original. Used by Apple Music for lossless streaming delivery.
In Simple Terms
Apple's version of FLAC — it shrinks audio files without losing any quality. Apple Music uses ALAC for its lossless streaming tier. If you're delivering to Apple platforms, your lossless files will be encoded in this format.
In Practice
Apple Music streams lossless audio as ALAC at up to 24-bit / 192 kHz for subscribers who enable the lossless quality setting. The format is natively supported on all Apple devices.
Common Confusion
ALAC and FLAC are functionally equivalent in quality — both are lossless. The difference is ecosystem compatibility. ALAC is native to Apple; FLAC is universal. Neither is better for audio quality.