M4Bindr – Convert MP3/M4A files into chaptered M4B audiobooks on iOS

Name: M4Bindr – Convert MP3/M4A files into chaptered M4B audiobooks on iOS
Availability: InStock
Author: NnaemekaO

by NnaemekaO·Mar 4, 2026·1 point·0 comments

Visit Project View on HN

AI Analysis

●●SolidCozySolve My ProblemNiche Gem

On-device M4B packager for DRM-free files, but iOS-only and narrow scope.

Strengths

•Entirely on-device processing eliminates trust concerns around uploading to web services
•Auto-chaptering per file is thoughtful UX that respects the common case (one file = one chapter)
•Proper M4B metadata (resume position, chapter navigation) works with Apple Books and BookPlayer

Weaknesses

•iOS-only (no Mac, Windows, or web alternative) severely limits addressable market vs iTunes or Audible Manager
•'Convert MP3 to M4B' is solved by desktop tools (ffmpeg, iTunes, Audiobook Maker); on-device is convenience, not necessity

Post Description

I built this because I had a library of DRM-free audiobooks as loose MP3 files — ripped CDs, Librivox recordings, purchases from DRM-free stores — and no good way to package them on iOS. Every solution either required a Mac, a third-party desktop app, or uploading files to a web service I didn't trust.

M4Bindr does the whole thing on-device. You import your tracks, reorder them, define chapters (manually or auto-generated per file), add cover art, fill in the metadata, and export a single .m4b that Apple Books and BookPlayer treat as a proper audiobook — with chapter navigation, resume position, the works.

It's not trying to handle DRM removal or format conversion beyond MP3/M4A — intentionally narrow scope. The goal was a clean, fast tool that does one thing well for people who already have the files and just want them packaged correctly. Would love feedback, especially from anyone who has edge cases around large files or unusual chapter structures.