MOV to M4B Converter
Processing entirely on your device — large files may take a moment.
MOV is Apple QuickTime’s native video container. iPhones and DSLRs record to it, but Windows and Android apps often struggle with it. Converting M4B to MP3 frees audiobooks to play on car stereos, dumb players and anything without chapter support.
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 MOV compares to M4B
| MOV | M4B | |
|---|---|---|
| Compression | H.264 up to ProRes | Lossy AAC + chapters |
| Quality | Can be studio-grade | Speech-optimized bitrates |
| Compatibility | Best in Apple ecosystems | Apple Books, Audible |
| Best for | Editing intermediates, ProRes | Chaptered audiobooks |
How to convert MOV to M4B
- 1
Select your files
Select your MOV video.
- 2
Convert instantly
The engine demuxes the container and encodes the audio track into your chosen format.
- 3
Download results
Download the M4B audio — the video track is simply dropped.
About the MOV format
MOV is Apple's QuickTime container, and technically the elder sibling of MP4 — same ISO base media format, same codec freedom. What sets it apart is professional video: ProRes intermediate codecs, timecode tracks and alpha channels live in MOV, which is why Final Cut, Premiere and every camera that shoots Apple ProRes hand you MOV files.
For everyday sharing it behaves exactly like MP4 (an H.264 MOV is interchangeable in practice). Where it hurts is size: ProRes and other editing codecs run hundreds of gigabytes per hour by design — they prioritize frame-accurate editing over compactness.
+ Strengths
- ✓Native to macOS, iOS and pro editing suites
- ✓Carries ProRes, alpha and timecode tracks
- ✓MP4-compatible for standard codecs
! Limitations
- −Editing codecs produce enormous files
- −ProRes playback needs capable hardware/players
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
Why convert MOV to M4B?
Converting makes sense where the strengths of M4B meet what MOV cannot give you. Chapter markers survive on Apple platforms Meanwhile Editing codecs produce enormous files One pass through the converter above puts your file on the right side of that trade-off.
Frequently asked questions
Is this MOV to M4B 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 MOV to M4B?
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.
Why is video conversion slower than image conversion?
Every frame has to be decoded and re-encoded. This site runs that work on your own CPU via WebAssembly — nothing is uploaded, but a multi-minute video reasonably takes a few minutes. Images, by comparison, are single-frame jobs.
Will the audio track be kept?
Yes. The audio is carried over and re-encoded to the standard audio codec of M4B, staying in sync with the video. If your MOV file has multiple audio tracks, the first one is used.