What is a .mp3 file?
MPEG-1 Audio Layer III · Audio · Fraunhofer / MPEG · 1993
MP3 is the format that made digital music portable. Its lossy compression shrinks songs to a fraction of their original size while sounding good to most ears, and it plays on essentially every device ever made.
What is a .mp3 file used for?
MP3 discards audio detail that is hard to hear, which is how it makes files so small. At higher bitrates the loss is subtle, at low bitrates you can hear it.
Its unmatched compatibility is the reason it never really died. Every phone, car stereo, browser and player handles MP3.
For archival or critical listening, lossless formats like FLAC keep every bit, but at several times the file size.
How to open a .mp3 file
The .mp3 format opens in the following apps, grouped by operating system. If one app does not work, try another from the same list. For a step-by-step walkthrough, see how to open a .mp3 file.
Windows
- Media Player
- VLC
- any browser
macOS
- Music
- QuickTime
- VLC
Linux
- VLC
- Rhythmbox
- mpv
Web
- Every browser
How to convert a .mp3 file
You can convert a .mp3 file to WAV, AAC, FLAC, M4A using a conversion tool or the export menu of an app that opens it.
.mp3 file signature (magic bytes)
Programs recognise a .mp3 file by the bytes at the start of the file, not by its name. These are the signatures for MP3. For a full breakdown, see the MP3 file signature page.
| Hex signature | Offset | Note |
|---|---|---|
| 49 44 33 | 0 | 'ID3' tag at start |
| FF FB | 0 | MPEG frame sync (no tag) |
| FF F3 | 0 | MPEG frame sync |
See the full magic-numbers reference for every format.
Frequently asked questions
What is a .mp3 file?
MP3 is the format that made digital music portable. Its lossy compression shrinks songs to a fraction of their original size while sounding good to most ears, and it plays on essentially every device ever made.
Is MP3 or WAV better quality?
WAV is uncompressed and technically higher fidelity, but a high-bitrate MP3 sounds close to identical to most listeners at a tenth of the size.
What bitrate should I use for MP3?
320 kbps is near-transparent for music. 128 kbps is fine for speech and podcasts.
Comparisons
Related formats
Sources
Details on this page were checked against authoritative references: