Convert MPEG-4 Audiobook (.m4b) to Windows Media Audio (.wma) 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 .wma file when it's ready.
WMA (Windows Media Audio) is Microsoft's proprietary codec. Converting M4B audiobooks to WMA moves content from Apple's ecosystem to Microsoft's. WMA audiobooks play in Windows Media Player and on older Zune devices. Windows does not have a native M4B-aware audiobook player like Apple Books, so WMA provides a familiar format for Windows-based audiobook listening through Windows Media Player's library.
Windows users without iTunes may prefer WMA for audiobook listening through Windows Media Player. Older Windows CE/Mobile devices and Zune players support WMA natively. Some Windows-based digital library systems (OverDrive's older platform) used WMA for audiobook downloads. DLNA servers may transcode for devices that prefer WMA.
FFmpeg decodes the M4B's AAC audio and encodes using wmav2 inside an ASF container with .wma extension. For spoken word, 64-96 kbps WMA provides good clarity. WMA Lossless is also available for archival-quality conversion. Chapter markers from M4B are not preserved — ASF supports chapter-like markers but they do not map from M4B automatically.
WMA at 64 kbps provides comparable quality to the M4B's AAC at 64 kbps for spoken word. WMA is slightly less efficient than AAC, so 96 kbps WMA better matches the original quality. For audiobooks, the difference is subtle.
| Device | M4B | WMA |
|---|---|---|
| Windows PC | Partial | Native |
| macOS | Partial | Partial |
| iPhone/iPad | Partial | Partial |
| Android | Partial | Partial |
| Linux | Partial | Partial |
| Web Browser | No |
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 WMA serves Windows-centric audiobook listening. Quality is good for spoken word at 64-96 kbps WMA.
Turvallinen siirto
HTTPS-salatut lataukset
Yksityisyys ensin
Tiedostot poistetaan automaattisesti käsittelyn jälkeen
Ei rekisteröitymistä
Aloita muuntaminen heti
Toimii kaikkialla
Mikä tahansa selain, mikä tahansa laite
| No |
| Ominaisuus | M4B | WMA |
|---|---|---|
| Koko nimi | MPEG-4 Audiobook | Windows Media Audio |
| Tiedostopääte | .m4b | .wma |
| Paras käyttökohde | Chapter support | Windows native |