6 May 2026 | 6 min read
Lossless audio formats: when FLAC beats WAV, and when it does not
Lossless and uncompressed are not synonyms. Understanding the difference is what lets you halve your archive size without ever touching quality.
Lossless means the decoded audio is bit identical to what went in. Uncompressed means no compression was applied at all. WAV and AIFF are uncompressed and therefore lossless. FLAC and ALAC are compressed and also lossless. The distinction matters when someone tells you compression always degrades sound.
How lossless compression works
A lossless encoder predicts the next sample from the previous ones and stores only the error. Music and dialogue are highly predictable at the sample level, so the error is small and encodes compactly. Reverse the prediction on playback and every original sample comes back exactly.
Typical savings
- Dialogue with room tone: 50 to 65 percent smaller.
- Dense music or crowd ambience: 25 to 40 percent smaller.
- Silence and handles: close to 90 percent smaller.
- 32 bit float recordings: still compress, just less predictably.
Where WAV still wins
Random access. A WAV can be scrubbed and streamed from disk without decoding, which is why editors and DAWs prefer it on a working timeline. WAV also carries Broadcast Wave and iXML metadata that some FLAC tooling handles poorly, so a careless round trip can lose your timecode and track names.
A practical archive policy
Keep the working set as WAV. Once a project is delivered and locked, convert the original poly files to FLAC for long term storage, verify a sample of them decode back correctly, and keep a written note of the metadata that mattered. Storage halves, quality does not move.
If you need to check what survived a conversion, drop the file in the inspector here and compare channel count, sample rate, bit depth and embedded names against the original.