CAF to AU Converter
Processing entirely on your device — large files may take a moment.
Core Audio Format and Sun Microsystems Audio exist for different jobs: CAF is Apple's Core Audio container — Logic Pro projects and macOS system sounds live in it, with support for huge files and any codec. Converting AU to WAV preserves the samples in a format every modern tool reads.
Because the whole conversion happens on your device, it is instant, unlimited and genuinely private — no accounts, no watermarks, no files on anyone's server. Multiple files are converted in one go.
How CAF compares to AU
| CAF | AU | |
|---|---|---|
| Compatibility | afconvert, Logic Pro, ffmpeg | Legacy Unix tools |
| Best for | Apple pro-audio workflows | Old system sounds and recordings |
How to convert CAF to AU
- 1
Select your files
Drag & drop your CAF files onto the area above, or click to browse. You can add multiple files at once for batch conversion.
- 2
Convert instantly
Click "Convert to AU". The conversion runs entirely inside your browser using WebAssembly — no upload, no queue, no waiting.
- 3
Download results
Download each converted AU file individually, or grab everything at once as a ZIP archive.
About the CAF format
CAF (Core Audio Format) is Apple's container for pro audio: 64-bit file offsets for recordings of any length, any codec as payload (PCM, ALAC, AAC), and time-stamped MIDI-style event chunks. Logic Pro exports it and macOS system sounds ship in it.
ffmpeg decodes the common PCM/ALAC payload variants, converting CAF to WAV or MP3 for use in any non-Apple DAW, player or web player.
+ Strengths
- ✓64-bit offsets — no size ceilings
- ✓Native to Logic Pro pipelines
- ✓Flexible codec payload
! Limitations
- −Apple-centric — rare outside macOS
- −Some CAF variants (UUID chunks) unsupported
- −Tag metadata Apple-specific
About the AU format
AU is Sun Microsystems' audio format from the Unix workstation age: a small header followed by µ-law (or PCM) samples. Java's applet era shipped it everywhere, and old Unix sound tooling still emits it.
Modern players increasingly skip it. Converting AU to WAV preserves the samples bit-for-bit while moving the file into universal territory — the standard rescue path for system sounds and old recordings.
+ Strengths
- ✓Simple, lossless sample storage
- ✓Native to old Unix/Java tooling
! Limitations
- −µ-law flavor sounds dated and mono
- −Dropped by modern players
Why convert CAF to AU?
Converting makes sense where the strengths of AU meet what CAF cannot give you. Simple, lossless sample storage Meanwhile Apple-centric — rare outside macOS One pass through the converter above puts your file on the right side of that trade-off.
Frequently asked questions
Is this CAF to AU converter really free?
Yes — completely free, with no sign-up, no watermark and no daily conversion limits. The site is supported by advertising.
Are my files uploaded to a server?
No. The conversion runs entirely inside your browser using WebAssembly, so your files never leave your device — that is what makes it instant and private.
Does it work on Windows, Mac, iPhone and Android?
Yes. Anything with a modern browser works: Windows, macOS, Linux, Android and iOS. No software installation is required.
Is there a file size limit for CAF to AU?
The only limit is your device's memory, since nothing is uploaded. Files up to a few hundred megabytes work fine on a modern desktop browser; very large files simply take a little longer.
Are tags like title and artist preserved?
Tag handling varies between target formats and this conversion focuses on the audio itself. For archival copies where tags matter, keep the original file; the converted copy is for playback and sharing.
Will converting CAF to AU reduce audio quality?
If AU is lossless, the output contains everything the CAF file contains — no further loss is added. If AU is lossy, one recompression pass is unavoidable; the quality slider controls how much. Loss that already happened in the source file can never be undone by converting.