AAC vs ALAC: Lossy vs Apple Lossless
Two Apple formats, one big difference: AAC is lossy and small, ALAC is lossless and large. Here's how to choose.
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Convert AAC files →AAC vs ALAC in one line
Both are Apple audio formats and both usually live inside an .m4a container — but AAC is lossy (small files, tiny quality trade-off) and ALAC (Apple Lossless Audio Codec) is lossless (perfect copies, big files). ALAC is essentially Apple's answer to FLAC.
| Property | AAC | ALAC |
|---|---|---|
| Type | Lossy | Lossless |
| Quality vs original | Excellent, not identical | Bit-perfect, identical |
| File size (3-min song) | ~5.8 MB (256 kbps) | ~20–30 MB |
| Container | .m4a (or .aac) | .m4a |
| Apple support | Native | Native |
| Best for | Everyday listening, mobile storage | Archiving, high-end playback |
The key difference
Because both can sit in .m4a files, people mix them up — but the codec inside is what matters. AAC discards data to stay small; ALAC keeps everything and just compresses it losslessly, so an ALAC file is a bit-perfect copy of the source at roughly 4–5× the size of an AAC version.
Can you hear the difference?
In everyday conditions — earbuds, a phone, a car, Bluetooth — almost nobody can distinguish 256 kbps AAC from ALAC. The lossless advantage shows up mainly on high-end equipment, for critical listening, or when you're editing and re-encoding repeatedly. For pure listening on the go, AAC gives you the same practical experience at a fraction of the size.
ALAC vs FLAC
ALAC and FLAC are both lossless and roughly equal in compression and quality. The practical difference is ecosystem: ALAC is native to Apple devices, while FLAC is the open, cross-platform standard. If your world is iPhone/Mac, ALAC fits; if it's mixed or Android/PC, FLAC is easier. See AAC vs FLAC for the lossy-vs-lossless breakdown.
When to choose each
Choose AAC for day-to-day listening and to keep your library small. Choose ALAC if you want a lossless master copy and you live in the Apple ecosystem. Many people archive in ALAC (or FLAC) and sync AAC to their phone.
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Convert AAC files →Frequently Asked Questions
Is ALAC better than AAC?
For fidelity, yes — ALAC is lossless and identical to the source. But it's far larger. AAC is better for everyday listening and mobile storage.
Are AAC and ALAC both .m4a?
They can be — both commonly use the .m4a container. The extension doesn't tell you which; check the file's codec info. See AAC vs M4A.
Is ALAC the same as FLAC?
Both are lossless with similar quality and size. ALAC is Apple-native; FLAC is the open cross-platform standard.
Should I rip my CDs to AAC or ALAC?
ALAC (or FLAC) if you want a perfect archive; AAC if you want small files and don't need a master copy.