Audio Formats Explained: MP3, AAC, FLAC, WAV & More
MP3, AAC, FLAC, WAV, OGG, M4A... there are dozens of audio formats out there. Here's what you actually need to know — no technical degree required.
The Two Categories: Lossy vs. Lossless
All audio formats fall into two buckets:
Lossy formats (MP3, AAC, OGG) throw away some audio data to make files smaller. It's like JPEG for images — you lose a tiny bit of quality, but the file is much more manageable.
Lossless formats (FLAC, WAV, ALAC) keep all the original audio data. Perfect quality, but much larger files.
For most people, lossy formats are the right choice. The quality loss is imperceptible in normal listening conditions.
The Common Formats
MP3 — The Universal Standard
Type: Lossy
File size: Small (~1 MB per minute at 128kbps)
Compatibility: Everything. Literally everything.
Best for: General use, sharing, portability
MP3 has been around since 1993 and plays on every device ever made. It's not the "best" format technically, but it's the most practical. When in doubt, use MP3.
AAC — Apple's Favorite
Type: Lossy
File size: Small (similar to MP3)
Compatibility: Excellent (Apple devices, most modern players)
Best for: iTunes, Apple Music, streaming
AAC is technically superior to MP3 at the same bitrate — slightly better quality in a slightly smaller file. It's what Apple uses for iTunes and what YouTube uses internally. The downside? Some older devices don't support it.
FLAC — The Audiophile Choice
Type: Lossless
File size: Large (~25-30 MB for a 4-minute song)
Compatibility: Good (most modern players, not iTunes)
Best for: Archiving music, high-end audio systems
FLAC preserves every bit of audio data while still compressing the file (unlike WAV). It's the gold standard for people who want perfect quality and have the storage space.
WAV — Raw and Uncompressed
Type: Lossless (uncompressed)
File size: Huge (~10 MB per minute)
Compatibility: Universal
Best for: Audio editing, professional work
WAV is the raw audio format — no compression at all. Files are massive, but there's zero quality loss. Audio professionals use WAV for editing because you don't want to compress and decompress repeatedly.
OGG (Vorbis) — The Open Source Option
Type: Lossy
File size: Small
Compatibility: Moderate (Spotify, games, Android)
Best for: Spotify, video games, open-source projects
OGG is technically excellent (better than MP3 at low bitrates) but never achieved mainstream adoption. You'll find it in Spotify streams and video game audio.
M4A — AAC in a Container
Type: Usually lossy (AAC inside)
File size: Small
Compatibility: Good (Apple ecosystem, modern players)
Best for: Apple devices, iTunes purchases
M4A is essentially AAC audio in an MP4 container. If you've bought music from iTunes, it's probably M4A. Quality is great, but compatibility isn't as universal as MP3.
Quick Decision Guide
- Need it to play everywhere? → MP3
- Staying in Apple ecosystem? → AAC/M4A
- Archiving music you love? → FLAC
- Editing audio professionally? → WAV
- Don't know what to pick? → MP3
Can You Hear the Difference?
Here's the uncomfortable truth: in blind tests, most people can't tell the difference between a 256kbps MP3 and a FLAC file. The differences are subtle and usually only apparent with:
- High-end headphones or speakers
- Quiet listening environments
- Music with complex instrumentation
- Trained ears actively looking for artifacts
If you're listening through AirPods on a subway, MP3 at 192kbps is genuinely fine.
Why MP3 Still Wins
Despite being "outdated" technology, MP3 remains the most practical format because:
- It plays on literally every device
- File sizes are reasonable
- Quality at 192-320kbps is excellent
- Everyone knows what an MP3 is
Sometimes the "best" solution isn't the technically superior one — it's the one that just works.