FLAC vs MP3 — Which Audio Format Should You Use?

FLAC and MP3 represent opposite ends of the audio quality spectrum. FLAC (Free Lossless Audio Codec) stores every bit of the original audio data; decoding a FLAC file produces a bit-for-bit identical copy of the original recording. MP3 (MPEG Layer 3) permanently discards data the psychoacoustic model considers inaudible, reducing file size by 70–90% at the cost of quality that cannot be recovered.

File size comparison: A 4-minute song at CD quality is approximately 40 MB as FLAC and 4–8 MB as MP3 (at 128–256 kbps).

Quality: FLAC is transparent — you hear exactly what was recorded. MP3 at 320 kbps is indistinguishable from lossless in most blind listening tests. MP3 at 128 kbps introduces audible artefacts in complex passages.

Compatibility: MP3 plays on every device ever made. FLAC requires a compatible player — supported on Android natively, but not by Apple's default Music app (use Plex, VLC, or a third-party player on iOS).

Use FLAC when: archiving your music collection, purchasing high-resolution downloads, or distributing final audio masters.

Use MP3 when: sharing audio files where the recipient may have limited storage, streaming on mobile, or compatibility with the broadest range of devices is required.

Summary: FLAC is the preservation format; MP3 is the distribution format. Keep FLAC masters and distribute MP3s — do not re-encode MP3 to FLAC (it adds file size without adding quality back).