M4B → WAV · Free · No Upload
Free Online M4B to WAV Converter — No Installation
Convert M4B (audiobook) to WAV (PCM) right in your browser, in seconds. Free, unlimited, and private: your file never leaves your device.
100% local processing: your file never leaves your device. Once the engine is ready, this tab can keep converting offline. Reopening or reloading offline may not work.
Supported formats:Files .m4b up to 300 MB — processed locally · Video and virtually any audio format are also accepted — we extract the audio automatically.
How it works
- 01
Upload the M4B file
Drag the .m4b file to the area above or click to select. Files up to 300 MB are accepted — everything is processed locally.
- 02
The conversion runs in your browser
FFmpeg (the same engine used by professionals) runs in WebAssembly right on the page. No bytes are sent to servers — total privacy.
- 03
Download the WAV
In seconds, the .wav file is ready for download, in standard 16-bit PCM, ready for any audio editor.
Frequently asked questions
Why convert M4B to WAV?
M4B features (chapters, resume-where-you-left-off) only work in Apple apps and dedicated readers — many players won't even open the file. Converting to MP3 makes the audiobook play on any device; chapters become one continuous audio track. WAV is the WORKING format: lossless editing, accepted by every audio software, and what telephony/IVR systems usually require (8 kHz mono WAV).
Where do M4B files come from?
Typically from audiobooks from iTunes/Apple Books, audiobook assembly tools (m4b-tool, Audiobook Builder) and downloaded audiobook libraries. Same MP4 container as M4A; the .m4b extension tells the player to treat it as an audiobook (bookmarks). Files easily exceed 10 hours — watch the size when converting.
Is it worth using WAV?
WAV is the WORKING format: lossless editing, accepted by every audio software, and what telephony/IVR systems usually require (8 kHz mono WAV). Microsoft/IBM RIFF container (1991); 16-bit/44.1 kHz stereo is 10.1 MB/min; RIFF has a 4 GB ceiling — longer recordings use W64 or RF64.
Do I lose quality when converting M4B to WAV?
There is no additional loss: the WAV preserves exactly what exists in the M4B file. Keep in mind that the original quality of the M4B (which is already compressed) is the ceiling — converting to a lossless format does not "recover" quality.
What if I need a transcript of this audio?
After converting, you can transcribe the file with AI on VoxScriber: 30 free minutes per month, with automatic punctuation and speaker identification. Ideal for WhatsApp audio messages, meetings, and interviews.
Is my file sent to any server?
No. All processing is local (FFmpeg compiled to WebAssembly running on the page). The file never leaves your device—it even works offline after the page loads.
Is there a size or quantity limit?
The limit is 300 MB per file (browser memory). There is no limit on the number of uses. For larger files, VoxScriber processes them on the server with uploads up to 5 GB.
Need the text from this audio? Transcribe with AI — 30 min free
Create free account →30 minutes/month free. No credit card required.
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Tools
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Convert M4B to OGG
OGG compresses well with high quality and is an open, royalty-free format—great for web and games.
Convert MP3 to WAV
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Convert M4A to WAV
Older stereos, car radios, and some corporate systems won't open M4A — an iPhone voice memo arrives and no one can play it.
Convert AAC to WAV
Raw .