You can easily upload the M4A audio files and convert them in a batch.

It supports a wide range of audio file formats - MP3, WAV, WMA, AAC, AIFF, OGG, M4A, AC3, M4B, M4R, and so on. It is a 100% free and safe media converter designed for the Windows system. NOTE: If you find there are some ads or the conversion speed is too slow when using the online tools to convert M4B audiobooks to MP3, then you can try to use a desktop tool, such as TuneFab iTunes Music Converter recommended in part 1, which is mostly ad-free and high-efficiency.The best way to free convert M4A audio files to MP3 format without any quality loss is by using MiniTool Video Converter. It's a relatively secure tool that outputs the converted iTunes M4B audiobooks of high quality. It's an online file converter that supports converting multiple contents, such as audio, video, ebook, audiobook, and so on.

The following M4B to MP3 online converter - CloudConvert, is one of our favorites.

Certainly, there are a lot of free online converters that are able to convert unprotected M4B files. Rather than using desktop software, perhaps you prefer online tools. And finally, click Start to get VLC to convert your M4B files. In the Destination section, click on Browse to choose an output folder. You may also customize a preset profile by clicking on the wrench icon. Then from the Settings section, choose Audio-MP3 from the Profile drop-down menu. From the File tab, click on the Add button and choose your preferred M4B audiobook, and then click on the Convert/Save button to proceed. From the menu bar, select Media > Convert/Save.

Audacity m4a to mp3