Audio format
The M4A format
M4A is AAC audio in an MP4 container, Apple’s everyday audio format. Apple popularised M4A with iTunes in 2003; it is AAC audio in an MP4 container, and what Voice Memos records.
When to use M4A
Use M4A for music and recordings on Apple devices, or anywhere AAC is accepted and size matters.
It is best for good-sounding audio at small sizes, and it opens on Apple devices, Android, browsers and most players; some older car stereos, Windows apps and forms refuse it.
How to open it: Apple Music, QuickTime, Windows Media Player, VLC and every browser play M4A files.
| Full name | MPEG-4 Audio |
|---|---|
| Extensions | .m4a, .m4b, .m4r |
| MIME type | audio/mp4 |
| Introduced | 2003 |
| Compression | Lossy |
| Typical quality | 128–256 kbps AAC |
| Support | Opens almost everywhere |
| Typical size | About 1 MB a minute at 128 kbps |
Good at
- Better quality than MP3 at the same size
- Native to iPhones and Macs
- Proper chapters and cover art
Not so good at
- Some car stereos, older players and upload forms accept only MP3
The common mistake
An .m4a can also hold lossless ALAC audio, several times larger; the extension alone doesn’t tell you which.
Convert M4A to another audio format
Convert to M4A from
Compare M4A with
Questions
What is an M4A file?
M4A (MPEG-4 Audio) is AAC audio in an MP4 container, Apple’s everyday audio format. Apple popularised M4A with iTunes in 2003; it is AAC audio in an MP4 container, and what Voice Memos records.
How do I open an M4A file?
Apple Music, QuickTime, Windows Media Player, VLC and every browser play M4A files.
How do I convert M4A to another format?
Pick the target on this page, or open the Audio Converter, drop the M4A file and choose a format. It converts in your browser, so nothing is uploaded.