Back to all tools
Convert AU to M4A
Convert AU to M4A format — 100% browser-based, no upload required.
2 cores · low tier
Drop a file here or click to select
Format will be auto-detected
About these formats
Source
AU
Sun/NeXT AudioSimple audio format from Sun Microsystems. Originally used in Unix systems and Java audio. Typically stores µ-law compressed audio.
Best for
Unix/Java audioLegacy systemsSimple audio storage
Advantages
- + Simple format
- + Java support
- + Compact for telephony
Limitations
- − Outdated
- − Low quality
- − Limited use
Target
M4A
MPEG-4 AudioAudio-only container using AAC codec. Standard format for iTunes/Apple Music purchases and podcast distribution.
Best for
iTunes/Apple MusicPodcastsAudiobooksApple ecosystem
Advantages
- + High quality AAC
- + Apple native
- + Chapters & metadata
- + Podcast standard
Limitations
- − Limited non-Apple support
- − Essentially AAC in MP4 container