01
One file, one address
Drop in the MP3 or M4B you own and pick the container you need. Songs and clips work too — no chapter marks required.
MP3 ⇄ M4B · 1.6 GB in
Convert an audiobook between MP3 and M4B.
Upload one file and get it back in the other container — chapters, cover art and metadata preserved. The download link is emailed and expires after 12 hours.
- Accepts
- M4B · MP3
- Up to
- 1.6 GB · 30 h
- Chapters needed
- No
- Cost
- Free
The swap
MP3
M4B
- Chapters kept
- Cover art kept
- Tags kept
- Full length
Need per-chapter files instead of one converted file? Split the audiobook
Convert your audiobook
Your file is processed, then deleted with its result after 12 hours. Only upload audio you own or are authorised to convert.
How it works
02
A faithful re-encode
MP3 and M4B never share a codec, so the audio is always re-encoded — but chapters, cover art and tags are carried across, not stripped.
ffmpeg · metadata kept
03
Grab it, then delete it
Download from this tab or the email. Press delete when you have it, or leave it and the file removes itself.
TTL 12 h · delete on demand