The GUI is simple and selfexplaining, very clever! Also thanks for implmenting CBR at kbps. Summary: Count: 0 of 1, characters Submit cancel The posting of advertisements, profanity, or personal attacks is prohibited. How to Convert MP4 to MP3 Files for a Mac. The file extension '.mp4,' short for MPEG-4, signifies a compressed video file. Download To MP3 Converter Free for macOS or. Read reviews, compare customer ratings, see screenshots, and learn more about To MP3 Converter Free.