What is a M4A file?
M4A is an MPEG-4 container holding audio, almost always AAC (Advanced Audio Coding). AAC was designed as MP3’s successor and gives noticeably better quality at the same bitrate, especially below 160 kbps. It is the format of the iTunes Store, Apple Music downloads, iPhone voice memos and YouTube’s audio streams.
Plain .aac files are the same codec without the MP4 wrapper; .m4b is the audiobook variant. Apple devices, Android, Windows 10+ and every browser play M4A, though a few older car stereos and MP3 players still only handle MP3.
| Extensions | .m4a, .aac, .m4b |
|---|---|
| MIME type | audio/mp4 |
| Codec | AAC-LC |
| Compression | Lossy |
| Typical bitrate | 128–256 kbps |
| Standard | ISO/IEC 14496-3, 1997 |
Reading .aac and .m4b works too; output is always .m4a with AAC-LC audio.
Convert M4A to…
Every conversion listed works in the converter above: add a M4A file and pick the target format.
Convert to M4A from…
Detailed guides: M4A to MP3
Part of the audio converter · all formats.