1.6k stars · MIT · v0.5.2 (2025-02-13) per ungh.cc/repos/sandreas/m4b-tool/releases/latest. CORRECTION: the 20 September note dated this tag 13 February 2026, which was wrong by a year. Nineteen months old, while ungh.cc reports code pushed 2026-04-18 · Track this in Scout
Merges, splits and chapterises audiobook files from the command line.
▶Repo detailsthe review · specs · pros & cons · install
What it is
A wrapper around ffmpeg and mp4v2, distributed as a single PHP archive file or as a container image. It handles MP3, AAC, OGG, ALAC, FLAC and M4B, and can read chapter names from MusicBrainz.
What it is good for. Anyone with a folder of loose audio files that should be one thing: an audiobook bought as 60 MP3s, a recorded lecture series, a long interview cut into takes. It also matters to anyone who records long spoken audio and wants to publish it with chapters, because chapter marks are what make a two-hour file navigable at all. The silence-detection option is the part worth trying first: it finds the natural breaks without you scrubbing through the file.
- MIT, free, and it does one job properly rather than being a whole media library.
- The container image carries ffmpeg, mp4v2 and the tagger with it, so there is nothing else to install.
- It can generate chapters automatically from silence, which saves the slowest part of the work.
- Its newest release, v0.5.2, is dated 13 February 2025 — nineteen months ago. The code itself was last pushed on 18 April 2026, five months ago, so the project is quiet rather than finished, and the README recommends the pre-release build over the stable one for bug fixes. That is an unusual thing for a project to say and you should know it before you rely on the stable file.
- A manual install wants PHP,
ffmpeg,mp4v2-utilsand optionallyfdkaac, which on some systems is more work than the tool itself. - It is a command with many options and no window. Getting the first merge right takes a few attempts.
- advplyr/audiobookshelf
It is the library and player for the files this produces, and it does not merge or chapterise anything itself.
Track this in Scout - sandreas/tone
By the same author, it reads and writes the tags and chapter data inside an audio file, and this project uses it.
Track this in Scout
# the container image carries every dependency docker run -it --rm -v "$(pwd)":/mnt sandreas/m4b-tool:latest \ merge /mnt/my-audiobook-folder/ --output-file="/mnt/audiobook.m4b" --auto-split-silence # macOS brew install sandreas/tap/m4b-tool
