Guide
FLAC vs ALAC vs MP3: what to put on your DAP
· 6 min read
Format arguments online run hot because people are usually answering two different questions at once. Separate them and the answer gets simple: what do I archive at home? and what do I carry in my pocket?They don't need the same answer — and mostly shouldn't.
The formats in one table
| Format | Type | Size per album* | Plays on |
|---|---|---|---|
| FLAC | Lossless | ~300–400 MB | Nearly every DAP, Rockbox, Android; not Apple Music app |
| ALAC | Lossless | ~300–400 MB | Apple everything; most DAPs |
| MP3 (320k) | Lossy | ~120 MB | Literally everything, including 2004 car stereos |
| AAC (256k) | Lossy | ~90 MB | Almost everything modern |
*A typical ~45-minute CD; your mileage varies with the music.
At home: lossless, no debate
Your library is the master copy. Storage costs almost nothing at library scale, and a lossless file can be converted to any other format, forever, without loss. A lossy file cannot be upgraded — transcoding MP3 to FLAC just makes a big MP3. Rip and archive in FLAC(or ALAC if you live entirely in Apple's ecosystem — they're equivalent in quality, and conversion between them is lossless in both directions). More in how to rip CDs to FLAC.
In your pocket: it depends on the pocket
A modern DAP with a big card(FiiO, HiBy, iBasso, Rockbox iPod with an SSD mod): carry FLAC. The hardware decodes it natively, a 512 GB card holds over a thousand albums lossless, and you never wonder whether you're hearing the rip or the transcode.
A small card, huge library, or long trips: high-bitrate lossy is the honest engineering answer. AAC at 256k and MP3 at 320k are transparent to nearly all listeners on nearly all material — double the music per gigabyte, and often better battery life, since decoding is lighter and the disk spins up less.
The car USB stick: MP3, no contest. Car head units are the least format-literate audio hardware still in service; MP3 in a plain Artist/Album folder tree plays in everything ever made.
The workflow that makes the question disappear
Keep one lossless library; transcode on the way out, per device. This is how Diskoteca's device profiles work: the DAP's profile syncs FLAC as-is, the car stick's profile converts to MP3 at your chosen bitrate during sync, and the library itself never changes. Set each device's answer once, and go back to arguing about music instead of formats.