M4A Audio (MIME: audio/mp4) is an audio file format using the MPEG-4 container, typically with AAC encoding. It is the default format for Apple Music, iTunes purchases, and iOS voice memos.
History and Development
M4A emerged as part of the MPEG-4 standard. Apple popularized it when the iTunes Store launched in 2003, using M4A as the format for purchased music. The .m4a extension distinguishes audio-only MPEG-4 files from .mp4 video files. Apple's DRM-protected version uses .m4p extension.
Technical Specifications
- Container: MPEG-4 Part 14
- Codec: Usually AAC (lossy) or ALAC (lossless)
- Bitrate: Typically 128-256 kbps (AAC)
- Sample rates: Up to 96 kHz
- Metadata: Rich MP4 atoms (title, artist, album art, lyrics)
- DRM: Optional FairPlay DRM (.m4p)
Common Use Cases
M4A is the standard for iTunes/Apple Music downloads, iOS recordings, podcasts distributed through Apple, and audiobooks. It's widely used in the Apple ecosystem for both music and spoken word content.
M4A vs Similar Formats
- M4A vs MP3: M4A (AAC) offers better quality at the same bitrate. MP3 has wider legacy device support.
- M4A vs FLAC: FLAC is lossless; M4A is typically lossy (unless using ALAC). FLAC is for archiving; M4A for daily listening.
- M4A vs MP4: Same container format. M4A is audio-only; MP4 contains video + audio.
How to Open and Edit
M4A plays natively on all Apple devices, iTunes, Windows Media Player, and most Android media players. VLC supports M4A on all platforms. Edit with GarageBand, Audacity, or Adobe Audition.
Frequently Asked Questions
Can Windows play M4A files?
Yes. Windows 10/11 can play M4A natively through the built-in media player. Older Windows versions may need VLC or a codec pack.
Is M4A better than MP3?
At the same bitrate, yes. M4A (AAC) produces better audio quality than MP3, especially at lower bitrates. Apple uses 256 kbps AAC, which is comparable to 320 kbps MP3.