Convert MPEG-4 Audiobook (.m4b) to Flash Video (.flv) 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 .flv file when it's ready.
FLV (Flash Video) is Adobe's legacy container from the Flash Player era. Converting M4B audiobooks to FLV packages spoken-word audio inside an FLV container with AAC or MP3 encoding. This niche conversion serves legacy RTMP streaming servers, archived Flash-based audiobook platforms, and content delivery systems that only accept FLV uploads.
Some legacy web-based audiobook platforms built during the Flash era (2005-2015) only process FLV files. RTMP ingest servers configured for audio streaming may expect FLV containers. Converting M4B to FLV enables delivery of audiobook content through these aging but still-operational systems.
FFmpeg decodes the M4B's AAC and muxes into an FLV container. If the M4B's AAC is compatible with FLV's AAC support, a stream copy is possible. Otherwise, re-encoding to MP3 provides broader FLV compatibility. FLV chapter support is limited to FLV metadata cue points, which do not directly map from M4B chapters.
With AAC stream copy: identical to M4B source. With MP3 re-encoding at 128 kbps: equivalent quality for spoken word. The FLV container adds no quality overhead.
| Device | M4B | FLV |
|---|---|---|
| Windows PC | Partial | Partial |
| 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 FLV serves legacy streaming and web platform infrastructure. Chapter markers are lost. Use AAC stream copy when possible for maximum quality preservation.
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 | FLV |
|---|---|---|
| Koko nimi | MPEG-4 Audiobook | Flash Video |
| Tiedostopääte | .m4b | .flv |
| Paras käyttökohde | Chapter support | Small file size |