How do AAC and M4Acompare? Here's everything you need to know to choose the right format — and how to convert between them.
Advanced Audio Coding
AAC is the successor to MP3, offering better sound quality at lower bitrates. It's the default audio format for Apple Music, YouTube, and most streaming platforms.
MPEG-4 Audio
M4A is an audio-only MPEG-4 container, typically containing AAC or ALAC encoded audio. It's Apple's preferred format for music files in iTunes and Apple Music.
| Specification | AAC | M4A |
|---|---|---|
| Full name | Advanced Audio Coding | MPEG-4 Audio |
| Extension | .aac | .m4a |
| MIME type | audio/aac | audio/mp4 |
| Category | Audio | Audio |
| Developer | ISO / Fraunhofer / Dolby / Sony / Nokia | Apple / ISO |
| Year introduced | 1997 | 2001 |
| Compression | Lossy | Lossy |
Both are excellent audio formats. AAC is preferred for apple music and itunes, while M4A shines at itunes music library.
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