What Is an M4B File?
A file with the M4B file extension is a MPEG-4 audiobook file. They’re often seen used by iTunes to store audiobooks. Some media players use the M4B format to store digital bookmarks along with the audio, letting you pause playback and then resume later. This is one reason they’re preferred over MP3s, which can’t save your place in the file. The M4A audio format is basically identical to M4B except that those types of files are used for music instead of audiobooks. Apple’s iPhone uses the MPEG-4 Audio format for ringtones, too, but those files are instead saved with the M4R extension.
How to Open an M4B File on an iPhone
iTunes is the primary program used to both play M4B files on a computer as well as to transfer audiobooks to an iPhone or another iOS device. You can do this by adding the audiobooks into the program and then syncing your device with iTunes.
How to Open an M4B File on a Computer
iTunes isn’t the only program that will play an M4B file on a computer. Windows Media Player works as well, but you might have to open it first and then browse for the M4B file manually from WMP’s menu since Windows may not recognize the file extension. Another option is to rename the extension from .M4B to .M4A because Windows does properly associate M4A files with Windows Media Player. Other multi-format media players that natively support the very similar M4A format, like VLC, MPC-HC, and PotPlayer, will also play M4B files.
How to Convert an M4B File
Since M4B files are often audiobooks, they’re usually pretty large and therefore are best converted with a dedicated, offline free file converter program. DVDVideoSoft’s Free Studio is one free M4B file converter that can save the file to MP3, WAV, WMA, M4R, FLAC, and other audio formats. Zamzar is another M4B converter but it runs in your browser, which means you have to upload the file to their website to have it converted. Zamzar can convert M4B to MP3 online, as well as to similar formats like AAC, M4A, and OGG.
How to Make an M4B File
If you want to put an audiobook on your iPhone, but the audio file isn’t in the M4B format, you’ll have to convert the MP3, WAV, or whatever format the file is in, to M4B so that the iPhone won’t mistake it for a song. Basically, you just have to do the opposite of what you read in the section above. Audiobook Binder can convert MP3 to M4B on macOS. Windows users can download MP3 to iPod/iPhone Audio Book Converter to convert multiple MP3s to M4B files or even combine the MP3s into one big audiobook.
