Audio format
What is a .mp3 file?
MP3 (MPEG-1 Audio Layer III) is a lossy audio format. It removes sounds the ear barely notices, so a song takes about a tenth of the space it would as uncompressed audio.
It isn’t the most efficient codec any more, but it plays on practically every device made in the last 25 years, which is why it’s still the default for sharing audio.
fileclay opens and writes MP3
MP3 vs AAC vs FLAC
| MP3 | AAC | FLAC | |
|---|---|---|---|
| Compression | Lossy | Lossy | Lossless |
| Quality at low bitrates | Fair | Better | Not applicable |
| Metadata | ID3 tags | MP4 tags | Vorbis comments |
| Playback | Everywhere | Almost everywhere | Most players |
| Best for | Sharing, podcasts | Apple devices, streaming | Archiving music |
Per minute
Calculated from the bitrate. WAV is CD quality: 44.1 kHz, 16 bits.
When to use MP3
Good for
- Music and podcasts you want to play anywhere
- Audio for older car stereos and players
- Sending recordings by email or chat
Not a good fit
- Master copies: every re-encode loses more
- Audio you still plan to edit
- Archives: FLAC keeps everything
How to open .mp3 files
| Platform | App | Notes |
|---|---|---|
| Windows | Media Player | Built in |
| macOS | Music, QuickTime Player | Built in |
| iPhone, iPad | Files, Music | Built in |
| Android | Files, any music app | Built in |
| Browsers | Chrome, Safari, Firefox, Edge | Drag the file into a tab |
| Editors | Audacity, Adobe Audition | Opens and exports |
Convert MP3 files
How to identify a .mp3 file
Most MP3 files start with “ID3”, the tag that holds title and artist. Files without tags start directly with an audio frame, usually FF FB.
It’s read here, in your browser. Only the first bytes.
Your file
What comes after
Questions about MP3
What bitrate should an MP3 have?
128 kbps is fine for speech, 192 kbps for everyday music, and 320 kbps is the highest the format allows.
Is MP3 lossy?
Yes. Detail is discarded on encoding and can’t be recovered, even by converting to WAV or FLAC.
Does converting WAV to MP3 lose quality?
Yes, though at 192 kbps or more most listeners don’t notice. Keep the WAV if you may need to edit it.
Is MP3 still patented?
No. The last patents expired in 2017, so anyone can use it without a license.
Is AAC better than MP3?
At the same bitrate, generally yes. MP3 remains the more compatible of the two.