MP3 file format
MPEG-1 Audio Layer III
MP3 is the most compatible audio format in the world. It uses lossy compression to make songs about a tenth the size of a CD-quality WAV, and plays on every device.
| Property | MP3 |
|---|---|
| File extensions | .mp3 |
| MIME type | audio/mpeg |
| Introduced | 1993 by Fraunhofer IIS / MPEG |
| Compression | Lossy |
| Typical bitrate | 128–320 kbps |
| 3-minute song | ≈ 4.3 MB at 192 kbps |
| Tags and cover art | Yes (ID3) |
| Compatibility | Universal |
| Best for | Music and podcasts on any device |
What is an MP3 file?
MP3 (MPEG-1 Audio Layer III) was developed largely at Germany's Fraunhofer Institute and standardised in 1993. It removes sounds the ear is unlikely to notice — a technique called perceptual coding — so a 3-minute song takes about 4 MB at 192 kbps instead of about 32 MB as WAV. The last MP3 patents expired in 2017, so it's now free to use.
Strengths and weaknesses
MP3 plays on every phone, car stereo, browser and media player. Its weakness is efficiency: AAC and Opus sound better at the same bitrate, and every re-encode loses a little more quality.
When should you use MP3?
Use MP3 whenever compatibility matters most. 192 kbps is transparent for most listeners; 320 kbps is the maximum. Keep lossless FLAC or WAV masters if you edit audio.