M4B to AIFF Converter
Processing entirely on your device — large files may take a moment.
MPEG-4 Audiobook and Audio Interchange File Format exist for different jobs: M4B is the audiobook flavour of M4A — AAC audio with chapter markers, used by Audible and Apple Books. AIFF imports cleanly into Logic Pro and older Mac audio tooling.
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 M4B compares to AIFF
| M4B | AIFF | |
|---|---|---|
| Compression | Lossy AAC + chapters | Uncompressed PCM |
| Quality | Speech-optimized bitrates | Bit-exact |
| Compatibility | Apple Books, Audible | Mac-first |
| Best for | Chaptered audiobooks | Mac recording and production |
How to convert M4B to AIFF
- 1
Select your files
Drag & drop your M4B 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 AIFF". The conversion runs entirely inside your browser using WebAssembly — no upload, no queue, no waiting.
- 3
Download results
Download each converted AIFF file individually, or grab everything at once as a ZIP archive.
About the M4B 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
About the AIFF format
AIFF is Apple's counterpart to WAV: uncompressed PCM in an IFF container, born with the classic Mac in 1988. It stores the same bit-perfect audio as WAV but carries metadata far better — iTunes-era tags, cover art and loop points all fit natively, which made it the default of Logic Pro and Mac-based audio production.
Functionally the WAV-versus-AIFF choice is platform history: same quality, same sizes, AIFF friendlier on Mac, WAV friendlier everywhere else. Converting between them is a lossless retagging exercise, nothing more.
+ Strengths
- ✓Bit-perfect uncompressed audio
- ✓Better metadata support than WAV
- ✓Native to macOS and Logic Pro
! Limitations
- −Same bulk as WAV (~10 MB/minute)
- −Windows tooling historically prefers WAV
Why convert M4B to AIFF?
Converting makes sense where the strengths of AIFF meet what M4B cannot give you. Bit-perfect uncompressed audio Meanwhile Chapters vanish in MP3 conversion One pass through the converter above puts your file on the right side of that trade-off.
Frequently asked questions
Is this M4B to AIFF 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 M4B to AIFF?
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 M4B to AIFF reduce audio quality?
If AIFF is lossless, the output contains everything the M4B file contains — no further loss is added. If AIFF 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.
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.