FLAC vs WAV vs ALAC: Lossless Audio Explained (+ Opus)
Three lossless formats with identical sound and very different jobs — plus the lossy champion nobody talks about, honest words on hi-res, and the one conversion rule you must never break.
Same sound, different jobs (≈3-minute CD track)
| Format | Type | ≈ Size | Plays on | Use for |
|---|---|---|---|---|
| WAV | Uncompressed | ~30 MB | Everything | Studio interchange, DAW timelines |
| FLAC | Lossless (~60%) | ~18 MB | Everything but old Apple SW | Music archiving (default pick) |
| ALAC | Lossless (~60%) | ~18 MB | Apple + modern everything | Archives in Apple households |
| MP3 320k | Lossy | ~7 MB | Literally everything | Universal sharing |
| Opus 128k | Lossy | ~3 MB | Browsers, apps, modern players | Voice, streaming, tiny files |
For the lossy side in full — MP3 vs AAC, bitrates, when lossy is audibly fine — see our MP3 vs WAV guide. And to pull audio out of video first, the extraction guide covers that step.
Two rules that prevent 90% of audio mistakes
Rule 1: never upconvert
MP3 → FLAC wraps degraded audio in a bigger file; the discarded data is gone forever. Derive everything downward from a lossless original (FLAC → MP3/AAC/Opus freely), and treat lossy files as dead ends.
Rule 2: hi-res hearing honesty
16-bit/44.1kHz already exceeds what rooms and ears resolve in finished listening — 24-bit matters when recording(headroom before clipping), not when replaying. Record 24-bit; don't rebuy libraries for it.
Conversion one-liners (FFmpeg)
WAV → FLAC (archive it)
ffmpeg -i track.wav -c:a flac track.flac
FLAC → ALAC for Apple (M4A container)
ffmpeg -i track.flac -c:a alac track.m4a
Anything → MP3 320k / Opus 96k (share it)
ffmpeg -i track.flac -c:a libmp3lame -b:a 320k track.mp3 ffmpeg -i track.flac -c:a libopus -b:a 96k track.opus
Whole folder to MP3 (Windows CMD)
for %i in (*.flac) do ffmpeg -i "%i" -c:a libmp3lame -b:a 320k "%~ni.mp3"
The library option
Convert the music library without babysitting loops.
FLAC archive on disk, MP3 mirror for the car, Opus for the phone — three libraries from one source. Formatif Pro ($8.95 one-time) batch-converts audio folders offline with per-file status, so a decade of rips becomes every format you need in one run.
Lossless audio questions, answered
FLAC vs WAV vs ALAC?
Identical sound. WAV: huge universal studio file. FLAC: ~60% size, open, default archive pick. ALAC: Apple's equivalent for Apple households.
Is FLAC better than MP3?
FLAC preserves everything; MP3 320k discards what you likely can't hear. FLAC's real value is archiving — derive perfect MP3s from it forever.
What is Opus for?
Voice, streaming, tiny files — beats MP3/AAC below ~128kbps. Discord, WhatsApp, YouTube low-bitrate, podcasts.
16-bit vs 24-bit audible?
In finished listening, essentially no. 24-bit matters when recording (headroom), not replaying.
MP3 to FLAC — quality back?
No. Upconverting wraps degraded audio bigger. Convert downward from lossless originals only.
Convert commands?
-c:a flac / alac / libmp3lame 320k / libopus 96k. WAV needs no codec flag. Batch loops above.
Keep learning
Every format your ears need, offline.
Formatif Pro ($8.95 one-time) and Formatif AI ($12.95 one-time) handle video, image, and audio conversion offline — with batch workflows, no file size limits, and a 3-day free trial.
The FFmpeg commands above are complete and free forever — pick whichever method fits your library size.
Written by
Founder of Formatif, a local-first offline media processing suite for Windows and Linux. Hadi writes about video, image, and audio formats, compression, and privacy-first desktop workflows.