Convert MPEG-4 Audiobook (.m4b) to iPhone Audio (.iphone-audio) online for free. Fast, secure audio conversion with no watermarks or registration.
Upload your .m4b file by dragging it into the upload area or clicking to browse.
Choose your output settings. The default settings work great for most files.
Click Convert and download your .m4a file when it's ready.
iPhone handles M4B audiobooks natively through Apple Books with full chapter navigation, bookmark resume, and variable playback speed. Converting M4B to iPhone Audio (M4A or AAC) is typically done to move audiobook content from the Books app to the Music app, strip audiobook-specific metadata, or share excerpts as standard audio files. The conversion removes chapter markers and the bookmark-on-close functionality that makes M4B unique.
Some iPhone users prefer a single app for all audio content. Others need audiobook segments as ringtones (M4R), voice samples, or shareable clips that M4B format complicates. Fitness apps that accept M4A for workout audio do not recognize M4B. Podcast apps can import M4A but not M4B for manual podcast feed content. The conversion broadens where and how the audio can be used on iPhone.
FFmpeg stream-copies the AAC audio from the M4B container to an M4A container, changing only the container format and stripping the chapter track. The operation is instant and lossless for the audio data. Optionally, the M4B can be split at chapter boundaries, producing numbered M4A files. iPhone treats M4A as music content, routing it through the Music app's library and Now Playing interface.
Stream copy preserves bit-identical audio. No quality change whatsoever. The only difference is the loss of chapter and bookmark metadata.
| Device | M4B | iPhone Audio |
|---|---|---|
| Windows PC | Partial | Partial |
| macOS | Partial | Partial |
| iPhone/iPad | Partial | Partial |
| Android | Partial | Partial |
| Linux | Partial | Partial |
| Web Browser |
Resolution: N/A
Bitrate: 320 kbps
OGG Vorbis preferred
Resolution: N/A
Bitrate: 256 kbps
AAC format required
Resolution: N/A
Bitrate: 128 kbps
Lossless FLAC/WAV for best quality
Resolution: N/A
Bitrate: 128 kbps
MP3 mono for spoken word
M4B to iPhone Audio changes how the content is categorized on your device. The audio quality is preserved perfectly when using stream copy.
Безопасная передача
Загрузки зашифрованы по HTTPS
Конфиденциальность прежде всего
Файлы автоматически удаляются после обработки
Без регистрации
Начните конвертировать мгновенно
Работает везде
Любой браузер, любое устройство
| No |
| Характеристика | M4B | iPhone Audio |
|---|---|---|
| Полное название | MPEG-4 Audiobook | iPhone Compatible Audio |
| Расширение | .m4b | .m4a |
| Лучше всего подходит для | Chapter support | iPhone optimized |