M4A (.m4a)
MPEG-4 audio container storing AAC-encoded audio. Used by Apple for iTunes downloads, Apple Music, and audio-only podcast exports.
- Extension
- .m4a
- MIME Type
- audio/mp4
Last updated
Overview
M4A is an MPEG-4 audio-only container that typically stores AAC-encoded audio. It is essentially a rename of the MP4 container restricted to audio tracks, introduced by Apple to distinguish audio files (M4A) from video files (MP4) in iTunes. The "M4" prefix means MPEG-4; the "A" means audio-only.
When you buy music from the iTunes Store or download from Apple Music, the files are delivered as M4A. The AAC audio inside is typically 256 kbps for purchased tracks. M4A also supports M4P (DRM-protected audio) and ALAC (Apple Lossless Audio Codec) for lossless quality.
Common Uses
- iTunes and Apple Music — all purchased and downloaded tracks use M4A
- GarageBand and Logic Pro exports — Apple DAWs default to M4A for audio bounce
- Podcast production — many podcast editors export to M4A for efficient distribution
- Audiobook distribution — Amazon Audible uses M4B (a variant of M4A with chapter support)
Advantages
- Better quality than MP3 — underlying AAC encoding is more efficient at the same bitrate
- Container metadata — supports cover art, album info, chapters, and lyrics reliably
- Lossless option — M4A with ALAC encoding is a lossless alternative to FLAC for Apple ecosystems
- Widely supported on Apple devices — plays natively on every iOS and macOS device
Limitations
- Limited non-Apple support — some older Android devices and non-Apple hardware do not play M4A by default
- DRM restrictions — M4P files purchased from iTunes before 2009 are DRM-locked to specific Apple IDs
- Not universally lossless — unless using ALAC encoding, M4A is still a lossy format
Supported Software
- Apple: iTunes, Music, QuickTime, GarageBand, Logic Pro, iOS/macOS natively
- Cross-platform: VLC, foobar2000, Windows Media Player (with codec), Audacity (with FFmpeg)
- Android: Native media player, VLC, Poweramp