MP3 vs WAV vs FLAC vs OGG vs AAC — which audio format should you pick?
Compare five audio formats by compression scheme (lossy / lossless / uncompressed), file size, compatibility, and use case. The right answer depends on whether you are distributing, editing, or archiving.
Four axes that separate audio formats
Picking an audio format is not a contest of “which one sounds best” — it is a question of what trade-off you want to make. Four axes carry most of the weight. Compression scheme (uncompressed / lossless / lossy) sets how much quality you sacrifice and how much room you keep for editing. Bitrate and file size drive streaming bandwidth costs and how many tracks fit on a phone. Compatibility matters as soon as the file leaves your machine — a car stereo, an enterprise CMS, a DAW, or a browser may refuse anything exotic. Use case flips the answer: distribution, editing, and archival have opposite optima.
There is no one-dimensional ranking where FLAC wins because it is lossless or MP3 loses because it is old. A podcast is a compatibility problem; a mastering session is a quality problem; an archive is a size-vs-fidelity problem; a web game is a latency problem.
Side-by-side comparison
| Property | MP3 | WAV | FLAC | OGG (Vorbis/Opus) | AAC |
|---|---|---|---|---|---|
| Compression | Lossy | Uncompressed PCM | Lossless | Lossy | Lossy |
| Typical bitrate | 128-320 kbps | 1411 kbps (44.1 kHz / 16-bit) | 700-1100 kbps | 96-256 kbps | 96-256 kbps |
| Size at same quality | Baseline (100%) | 800-1000% | 400-600% | 60-80% | 70-90% |
| Metadata | ID3v2 | RIFF / BWF (limited) | Vorbis Comment (rich) | Vorbis Comment | iTunes-style + ID3 |
| Where it plays | Everywhere | Everywhere | Most DAWs, modern browsers | Firefox / Chrome, web delivery | iTunes / YouTube / Apple Music / most streaming |
| Year introduced | 1992 (ISO/IEC 11172-3) | 1991 (Microsoft / IBM) | 2001 (Xiph.Org) | Vorbis 2002 / Opus 2012 (IETF RFC 6716) | 1997 (ISO/IEC 13818-7) |
The size column uses CD-quality WAV (44.1 kHz / 16-bit stereo) as the “uncompressed reference”. MP3 at 192 kbps, AAC at 160 kbps, and Opus at 96 kbps are roughly equivalent in perceived quality, with Opus reaching the same fidelity at the lowest bitrate. FLAC’s distinguishing trait is bit-exact decoding back to the original PCM — the same audio you would get from WAV, in roughly half the disk space.
Use case → recommended format
Music distribution and podcast publishing: AAC or MP3. Apple Music / YouTube / Spotify will re-encode to AAC or Opus on their end, so what you ship is mostly an upload-side compatibility question. MP3 remains the de-facto standard inside podcast RSS feeds.
DAW editing and mastering: WAV. Uncompressed PCM survives any number of export round-trips without quality loss, and every major DAW (Pro Tools, Logic, Cubase, Reaper) treats it as the canonical interchange. Keeping intermediates in a lossy format means quality erodes with every save.
Long-term archives and lossless libraries: FLAC. The same bits as WAV after decoding, at 50-60 % of the size, with rich Vorbis Comment tagging. Standard practice for CD ripping and for keeping 24-bit / 96 kHz hi-res masters.
Web delivery, in-game audio, voice calls: OGG Opus. Same perceived quality at lower bitrates, plus very low encoding latency (~20 ms), which is why WebRTC and Discord adopted it as the voice codec. If the MP4 / iOS compatibility gap is acceptable, Opus is the most efficient pick.
Voice memos and meeting notes: Opus when bytes matter, AAC when compatibility matters more than size.
Converting locally in the browser
Knowing which format you want still leaves the conversion problem — what you have is rarely already in the format you need. audio-convert uses ffmpeg.wasm to transcode between MP3, WAV, FLAC, OGG, AAC, and M4A, with bitrate and sample-rate options exposed. Unlike upload-style converters, there is no code path that ships your recordings to a server.
The biggest pitfall is lossy → lossy re-encoding. Chaining MP3 → AAC → Opus quietly trims harmonics and high-frequency detail at every step, even when the difference is inaudible at first listen. If the original master (WAV or FLAC) is still on hand, convert once from the master to the target format, never through intermediate lossy stops. If all you want is a smaller file in the same format, audio-compressor lets you re-pick the bitrate without changing format. The source is auditable on GitHub, and the DevTools Network tab makes it straightforward to confirm the audio never leaves the browser.