How do M4A and AIFFcompare? Here's everything you need to know to choose the right format — and how to convert between them.
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.
Audio Interchange File Format
AIFF is Apple's uncompressed audio format, the macOS equivalent of WAV. It stores full-quality audio data and is commonly used in professional audio production on Apple systems.
| Specification | M4A | AIFF |
|---|---|---|
| Full name | MPEG-4 Audio | Audio Interchange File Format |
| Extension | .m4a | .aiff |
| MIME type | audio/mp4 | audio/aiff |
| Category | Audio | Audio |
| Developer | Apple / ISO | Apple |
| Year introduced | 2001 | 1988 |
| Compression | Lossy | Lossless |
M4A is practical for everyday listening with good compression. AIFF is essential for professional audio work where every detail matters.
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