Comparison
MP3, M4A, WAV, or FLAC: which should you pick?
Short answer
Pick MP3 when the file has to play on anything, including old hardware and car stereos. Pick M4A when your devices are modern and you want the same quality in a smaller file, which is also the best choice when the source came from YouTube. Pick WAV when you are about to edit the audio and will re-save it several times. Pick FLAC when you are archiving something you want to keep bit-for-bit. For ordinary listening, the difference between MP3 at 320kbps and M4A is inaudible to almost everyone.
Side by side
| Format | Lossy? | Per minute | Choose it when |
|---|---|---|---|
| MP3 (320kbps) | Yes | 2.4 MB | It has to play on absolutely anything |
| M4A (AAC) | Yes | 1.5 MB | Modern devices, and the source is a video |
| WAV | No | 10 MB | You are editing and will re-save repeatedly |
| FLAC | No | 5 MB | You are archiving and want an exact copy |
Lossy and lossless, in one paragraph
MP3 and M4A are lossy: they permanently discard parts of the signal a listener is unlikely to notice, which is how they get small. WAV and FLAC are not: WAV stores the audio raw, FLAC compresses it the way a ZIP does, so it comes back out identical at roughly half the size.
That distinction only matters at the point of capture. If the audio you are saving was already lossy, and anything from a video platform was, converting it to FLAC preserves compressed audio perfectly. It does not undo the compression.
When the difference is audible
In careful listening tests, most people cannot distinguish a 320kbps MP3 from a lossless source on normal equipment. What people do reliably hear is repeated re-encoding, low bitrates below about 160kbps, and poor source material.
So the practical advice is unglamorous: convert once, from the best source you have, at a high bitrate, and stop worrying about the format.
Where each one bites you
MP3 cannot store more than two channels usefully and its metadata support is fiddly, but nothing refuses to play it. M4A is occasionally awkward on old Android and cheap car head units. WAV files are enormous and carry metadata badly, so a WAV library is painful to browse. FLAC is unsupported by some older hardware and, notably, by a few car systems, though every desktop and phone player handles it.
Last checked .