CAF to F4B Converter
Processing entirely on your device — large files may take a moment.
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. Convert F4B audiobooks exactly like M4B — to MP3, M4A or WAV.
iLoveConverter processes everything locally on your computer, which makes it private and fast: no upload wait, no server storage, no limits. Add as many files as you like — batch conversion is built in.
How CAF compares to F4B
| CAF | F4B | |
|---|---|---|
| Compatibility | afconvert, Logic Pro, ffmpeg | Apple Books, Audible |
| Best for | Apple pro-audio workflows | Chaptered audiobooks |
How to convert CAF to F4B
- 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 F4B". The conversion runs entirely inside your browser using WebAssembly — no upload, no queue, no waiting.
- 3
Download results
Download each converted F4B 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 F4B format
M4B is M4A wearing an audiobook badge: the same AAC audio in an MP4 container, plus chapter markers that Apple Books and Audible apps render as a scrubbing timeline. Buy an audiobook outside Audible and it likely arrives as M4B.
The format is deliberately chained to Apple's book ecosystem. Converting M4B to MP3 sets the book free: car stereos, gym players, old iPods and every app without chapter support will play it — though the chapter marks themselves are flattened away.
+Strengths
- ✓Chapter markers survive on Apple platforms
- ✓Efficient AAC audio
!Limitations
- −Chapters vanish in MP3 conversion
- −Non-Apple support is patchy
Why convert CAF to F4B?
Converting makes sense where the strengths of F4B meet what CAF cannot give you. Chapter markers survive on Apple platforms 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 F4B 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 F4B?
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.
Will converting CAF to F4B reduce audio quality?
If F4B is lossless, the output contains everything the CAF file contains — no further loss is added. If F4B 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.
Can I convert a whole folder of CAF files?
You can select many files at once and they are processed in a single batch. Output files land in one ZIP download when there is more than one result.