FLAC vs WAV vs ALAC: Which Lossless Format to Archive In

Lossless means what it says: decode the file and you get back exactly the samples that went in, bit for bit. FLAC, WAV and ALAC all do this. So if quality is identical across all three, the choice comes down to size, metadata and compatibility — and those differences are large enough to matter.

This guide compares them and suggests which to use for an archive. If you have already decided, the FLAC converter and WAV converter handle the conversion.

WAV: uncompressed and universal

WAV stores raw PCM samples with essentially no compression. A CD-quality stereo recording occupies about 10 MB per minute, so a four-minute song is around 40 MB and an album approaches half a gigabyte.

In exchange you get complete, unquestioned compatibility. Every audio editor, DAW, sampler, CD authoring tool and embedded device reads WAV without a plugin or a conversion prompt. It is the lingua franca of audio software, and that is exactly what it should be used for: a working format during editing, mastering or CD authoring.

Its weakness is metadata. WAV's tagging support is an afterthought bolted on decades later, handled inconsistently by different software. Artist, album and cover art frequently fail to survive a trip between applications, which makes WAV a poor choice for a music library you intend to browse.

FLAC: lossless with the size and tags sorted out

FLAC compresses the same samples the way ZIP compresses a document — smaller on disk, identical when decoded. Typical compression is 40 to 60 per cent depending on the music, so that 40 MB WAV track becomes roughly 20 MB with nothing lost.

Crucially, FLAC has proper metadata built in from the start: artist, album, track number, year, genre and embedded cover art, all handled consistently by every player that supports the format. That combination — lossless, half the size, properly tagged — is why FLAC is the default choice for serious music archives.

Support is broad: Android and modern iOS play it natively, as do VLC, foobar2000, Plex, Roon and most network streamers. The gaps are old car head units and some cheap portable players, which is a good argument for keeping FLAC at home and generating MP3s from it for the road.

ALAC: Apple's equivalent

ALAC — Apple Lossless — does the same job as FLAC with comparable compression. It exists because Apple wanted its own lossless format, and it remains the one that iTunes, Music and older iPods handle natively.

Apple has since added FLAC support in various places, which has taken most of the reason to prefer ALAC away. Its practical downside is narrower support elsewhere: plenty of non-Apple hardware and software reads FLAC but not ALAC. Unless your entire ecosystem is Apple and always will be, FLAC is the safer archival choice.

Which to use for what

Archiving a collection: FLAC. Lossless, half the size of WAV, and tags that behave.

Editing, mastering, CD authoring: WAV. It is what the software expects, and the size penalty is temporary.

A strictly Apple household with an older iTunes library: ALAC is reasonable, though FLAC works nearly as well now.

Phones, cars, gym devices, sharing: none of them. Use MP3 or M4A — a tenth of the size, and the quality difference is inaudible in those settings.

The point everyone gets wrong

Converting a lossy file to a lossless one does not make it lossless. An MP3 turned into FLAC or WAV is a large, faithful copy of a file that already had detail removed. The result sounds exactly like the MP3 and takes up ten times the space.

Lossless conversion is worthwhile in two situations: when the source is genuinely lossless and you are changing format for size or compatibility, and when you want a stable working copy that will not degrade further through repeated edits and saves. Outside those cases it is storage spent for nothing. The bitrate guide explains the same principle from the lossy side.

A practical two-tier setup

The arrangement that works for most people is simple. Keep a lossless master library in FLAC — from CD rips, high-resolution purchases or your own recordings. Generate lossy copies from it for whatever needs them: MP3 for the car and older devices, M4A for iPhones. When a new device or format appears, generate fresh copies from the masters rather than converting the copies, which would stack a second generation of loss.

That way the archive keeps its quality permanently and the portable copies are disposable. The bulk conversion guide covers generating those copies efficiently, and the format comparison covers which lossy format to generate for which device. To build the archive itself, start with the FLAC converter.