Audio Format

M4B Converter — Free Online

Convert MPEG-4 Audiobook files to and from other formats. Fast, free, no registration required.

Drop files here or click to browse

Supports: M4B files

Max: 100MB (free) · 2GB (Pro)

or import from

Secure Transfer

HTTPS encrypted uploads

Privacy First

Files auto-deleted after processing

No Registration

Start converting instantly

Works Everywhere

Any browser, any device

Convert to M4B

MP3 to M4B→WAV to M4B→FLAC to M4B→M4A to M4B→OGG to M4B→AAC to M4B→

Convert from M4B

M4B to MP3→M4B to WAV→M4B to FLAC→M4B to M4A→M4B to OGG→M4B to AAC→

What is M4B?

M4B is the MPEG-4 audiobook format used by Apple iTunes and many audiobook platforms. It supports chapter markers, bookmarking, and AAC compression for efficient audiobook delivery.

Format Details

Full Name: MPEG-4 Audiobook
Extension: .m4b

Key Features

Chapter support
Bookmark resume
iTunes compatible
AAC compression

Frequently Asked Questions

Upload your file, select M4B as the output format, and click Convert. Your converted file will be ready to download in seconds.

You can convert most audio formats to M4B, including MP3, WAV, FLAC, M4A, OGG, and more.

Yes! You can convert up to 5 files per day completely free. No registration required.