Audio Formats Explained: MP3, WAV, FLAC, AAC, OGG & More
Published March 4, 2026 · 10 min read
Whether you're a music listener, podcaster, or audio professional, understanding audio formats helps you make better decisions about quality, file size, and compatibility.
Lossy vs. Lossless: The Fundamental Divide
Lossy formats (MP3, AAC, OGG) permanently discard audio information that psychoacoustic models determine most humans can't hear. This achieves 5–12× compression versus raw audio. Once data is removed, it can never be recovered.
Lossless formats (FLAC, ALAC, WAV) preserve every bit of the original recording. No information is ever lost. Files are larger (2–5×), but you always have the ability to produce a perfect copy or re-encode to any other format.
MP3
The most universally recognized audio format, MP3 (MPEG-1 Audio Layer III) launched the digital music revolution. At 320 kbps, MP3 is virtually indistinguishable from the original for most listeners. At 128 kbps, compression artifacts become noticeable — a metallic swirling effect on cymbals and high frequencies. Supported by literally every audio device made in the last 25 years.
AAC (Advanced Audio Coding)
The successor to MP3, adopted by Apple for iTunes and YouTube for its streaming audio. AAC delivers better quality than MP3 at the same bitrate, especially below 128 kbps. It's the default format for iPhone recordings, Apple Music downloads, and most streaming platforms.
OGG Vorbis
An open-source, royalty-free lossy format. OGG Vorbis offers quality comparable to AAC at similar bitrates. It's widely used in gaming (Unity, Unreal Engine) and by Spotify for streaming. Browser support is excellent across Chrome, Firefox, and Edge.
Opus
The newest and most technically advanced lossy codec. Opus excels at every bitrate from 6 kbps (voice) to 510 kbps (transparent music). It's used by Discord, WhatsApp, and Zoom for voice chat. For music, Opus at 128 kbps is roughly equivalent to MP3 at 192 kbps.
WAV
Uncompressed PCM audio in Microsoft's RIFF container. WAV files are large — a 3-minute song at CD quality (44.1 kHz, 16-bit, stereo) takes about 30 MB. WAV is the standard interchange format for audio editing because there's zero processing overhead and universal compatibility.
FLAC (Free Lossless Audio Codec)
The gold standard for lossless audio distribution. FLAC compresses CD-quality audio to roughly 50–60% of the original size — completely losslessly. It supports metadata tags, album art, and up to 32-bit/384 kHz resolution. Used by Tidal, Qobuz, and audiophile music stores. Not supported natively by Apple devices (use ALAC instead).
ALAC (Apple Lossless)
Apple's lossless codec. Technically similar to FLAC in compression ratio, but wrapped in an M4A container for Apple ecosystem compatibility. Apple Music uses ALAC for their lossless tier. If you're an Apple user who wants lossless, ALAC is the path of least resistance.
Format Comparison Table
| Format | Type | 3 min song | Quality |
|---|---|---|---|
| WAV | Uncompressed | ~30 MB | Perfect |
| FLAC | Lossless | ~18 MB | Perfect |
| MP3 320 | Lossy | ~7 MB | Near-transparent |
| AAC 256 | Lossy | ~5.5 MB | Near-transparent |
| OGG 192 | Lossy | ~4.2 MB | Very good |
| Opus 128 | Lossy | ~2.8 MB | Very good |
| MP3 128 | Lossy | ~2.8 MB | Acceptable |
Which Format Should You Use?
- Archiving your music collection: FLAC (or ALAC if Apple-only)
- Sharing via messaging: MP3 320 kbps (universal compatibility)
- Podcast publishing: MP3 128–192 kbps (industry standard)
- Web audio/games: OGG Vorbis or Opus
- Audio editing: WAV (zero processing overhead)
- Streaming upload: FLAC (the platform will transcode)