Audio to M4B Converter

Free Online Audiobook Creator

audio_file

Drag & drop audio files here, or browse

MP3, M4A, OGG, FLAC, WAV, etc.

How It Works

  1. Add audio files Drag and drop your audio files or click to browse. MP3, M4A, FLAC, WAV, and more are supported.
  2. Set metadata Enter the book title, author, and narrator. Look up cover art from Open Library or upload your own.
  3. Convert Click convert and the tool combines your files into a single M4B with chapter markers. Everything runs locally in your browser.
  4. Download Download your finished audiobook file, ready for Apple Books, iTunes, or any M4B-compatible player.

Features

Supported Formats

FAQ

What is an M4B file?

M4B is an audiobook format based on MPEG-4. It supports chapters, bookmarks, and cover art, making it the standard format for audiobooks in Apple Books, iTunes, and many other audiobook players.

Is my data safe?

Yes. All processing happens entirely in your browser using WebAssembly. Your audio files are never uploaded to any server. Nothing leaves your device.

What audio formats are supported?

MP3, M4A, FLAC, WAV, OGG, AAC, WMA, and most other common audio formats. The converter uses FFmpeg under the hood, which supports a wide range of codecs.

Do I need to install anything?

No. The converter runs entirely in your browser. There is nothing to download or install. Just open the page and start converting.

Is there a file size limit?

There is no hard limit, but very large files (over 2 GB total) may be slow or run into browser memory constraints. For best results, keep total input size under 1 GB.

Can I add cover art?

Yes. You can upload a JPEG or PNG image as cover art, or use the built-in Open Library lookup to automatically find and attach cover art based on your book title.