Choose a .MP4 video or any other supported media file from your device or cloud storage. Select .mp3 as the conversion format from the dropdown menu. Click the Start button to start converting your file. When the conversion is completed, click on the download link to get your converted .MP3 file.
Another free method to convert M4B to MP4 is to use Audacity. Since Audacity is a free open-source audio editing software, you can use it as a makeshift converter. The basic workflow is to import M4B audio file and export it as MP3, and skip the editing part.The data can be a raw bitstream in an audio coding format, but it is usually embedded in a container format or an audio data format with defined storage layer. This online audio converter supports vast conversions including OGG to MP3, OPUS to MP3, WAV to MP3, MP4 to MP3, M4A to MP3, MP3 to AAC, etc. To do this choose Audacity > Preferences: Import / Export and where it says "When importing audio files", check the radio button: Copy uncompressed files into the project (safer) (default setting) . Another possibility is to use Max, a free software CD ripping and encoding application. It has full support for encoding into the FLAC lossless