Audio Format Comparison

M4A vs AIFF — Apple AAC vs Apple Uncompressed

M4A and AIFF are both Apple-native audio formats. M4A typically holds AAC (lossy compressed) audio. AIFF stores uncompressed PCM. They serve opposite purposes: M4A is for distribution (small files, good quality), AIFF is for editing (uncompressed, immediate access). Both work natively in Logic Pro, GarageBand, and Apple Music.

M4AvsAIFF

Quick Verdict

Use M4A when…

Use M4A for music storage, distribution, and casual playback on Apple devices. M4A files are small enough for cloud sync and large libraries.

Use AIFF when…

Use AIFF for audio editing, sample libraries, and any production workflow where you need immediate uncompressed access for editing. AIFF is Apple's standard for working files.

M4A vs AIFF: Feature Comparison

Feature	M4A	AIFF
Compression	Lossy (AAC) or lossless (ALAC)	Uncompressed PCM
File size (4 min stereo)	~8 MB at 256 kbps	~40 MB at 16-bit/44.1 kHz
Decoding overhead	CPU decode required	Zero — direct playback
Logic Pro / GarageBand	Native	Native (preferred for editing)
Apple Music	Native distribution format	Not a distribution format
Cross-platform	Universal	Universal but Apple-rooted

When M4A wins

✓Compression: Lossy (AAC) or lossless (ALAC)
✓File size (4 min stereo): ~8 MB at 256 kbps
✓Decoding overhead: CPU decode required

When AIFF wins

✓Compression: Uncompressed PCM
✓File size (4 min stereo): ~40 MB at 16-bit/44.1 kHz
✓Decoding overhead: Zero — direct playback

Frequently asked questions

Should I use M4A or AIFF for podcasts?

Distribute as M4A or MP3 (smaller). Edit and master in AIFF. Most podcast hosts (Anchor, Libsyn, Buzzsprout) accept M4A and MP3 distribution; AIFF would be too large.

Is M4A better than AIFF?

Different uses. M4A is better for distribution and storage; AIFF is better for editing. Most audio production workflows use AIFF as the working format and export to M4A or MP3 for delivery.