Library & files
FLAC
FLAC is a lossless compressed format: it shrinks a file without discarding any audio, so decoding returns the original samples exactly. It typically lands around 60% the size of the WAV it came from.
Measured in real DJ libraries
FLAC holds 5.2% of a real DJ library — behind AIFF, ahead of WAV, and closer to both than the arguments about them suggest.
FLAC is the same audio as the WAV in roughly 60% of the space, so on the merits it should have taken the lossless category outright. It has not. The three lossless formats sit within a couple of points of each other in real collections, which says the deciding factor is player support and old software defaults, not what the format does. That support is worth checking rather than assuming — the moment to discover a player will not load your library is not when you are plugging in.
Updated daily from Rekordbox collections DJs have imported to Mixgraph. Method: what lossless actually guarantees.
Why it matters
FLAC is the format that makes the lossless argument affordable. Uncompressed audio is large enough that DJs abandon it for space reasons alone; FLAC removes most of that penalty and gives back a bit-identical file, so the only real cost is player support.
That support is the thing worth checking rather than assuming. Club players and DJ software have been reading FLAC for years now, but firmware varies, and the moment to discover a player will not load your library is not when you are plugging in.
Frequently asked
Is FLAC better than WAV?+
It is identical in sound and smaller on disk, so for storage it is strictly better. WAV wins only where a piece of software or hardware refuses to read FLAC.
Can club players read FLAC?+
Modern ones generally can, and have for years. Older units and unusual setups are the exception, which is why a lossy backup copy of the set costs little and removes the risk.
Does FLAC lose quality?+
No. It is lossless by definition — decode a FLAC and you get the original samples back exactly, bit for bit.
Related terms
Lossless
Lossless means the encoding discards nothing: decode the file and the original samples come back bit for bit. WAV, AIFF, FLAC and ALAC are lossless; MP3 and AAC are not.
WAV and AIFF
WAV and AIFF are uncompressed audio containers — the raw samples, no encoding. They sound identical to each other and differ mainly in how they store tags and which software wrote them.
Bit rate
Bit rate is how much data one second of audio uses, in kilobits per second. It decides the file size, and on a lossy format it decides how much of the original recording survives the encoding.
Lossy compression
Lossy compression shrinks a file by discarding audio a listener is unlikely to notice. What it removes is gone permanently, and encoding an already-lossy file removes more on top.
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