.M4B File Extension

MPEG-4 Audiobook

Developer Apple
3.6  |  39 Votes
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What is an M4B file?

An M4B file is an audiobook most often used by Apple iTunes and Apple Books. It contains audio that is stored in the MPEG-4 format and compressed using AAC encoding. M4B files are nearly identical to .M4A files except that they support book-related features, such as chapter breaks and bookmarking.

More Information

Screenshot of a .m4b file in Apple Books
M4B file open in Apple Books

Apple copy-protects the M4B files they provide using FairPlay DRM. This means M4B files you download via iTunes or Apple Books can be played only on authorized computers and Apple devices, using iTunes or Apple Books. Therefore, if you are having trouble playing an M4B file, it might be because you are not playing it in iTunes or Apple Books, or because your device is not authorized to play it.

How to open an M4B file

On Windows, you can open an M4B file with Apple iTunes. On Macs and other Apple devices, you can open an M4B file with Apple Books.

Some free audiobook libraries, such as LibriVox, also provide audiobooks in the M4B format. These files are not copy-protected, so you can play them using third-party media players such as VideoLAN VLC media player.

How to convert an M4B file

You can use VideoLAN VLC media player (multiplatform) to convert non-copy-protected M4B files to the following audio formats:

  • .MP3 - MP3 Audio
  • .OGG - Ogg Vorbis Audio
  • .FLAC - Free Lossless Audio Codec

TuneFab iTunes Audio Converter (Windows, Mac) and Viwizard Audio Converter (Windows, Mac) can remove copy-protection from protected M4B files and convert them to MP3 and other audio formats. Keep in mind that removing copy-protection for your own use is legal, but sharing previously copy-protected files is illegal.

Programs that open M4B files

Verified by FileInfo.com

The FileInfo.com team has independently researched the MPEG-4 Audiobook file format and Mac, Windows, Linux, Android, and iOS apps listed on this page. Our goal is 100% accuracy and we only publish information about file types that we have verified.

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