While Getmp3 works, I’ve also had reliable results with a desktop software solution. For maximum control over the audio quality and to avoid any web service limits, using a dedicated video converter https://www.movavi.com/video-converter/convert-mov-to-mp3.html#:~:text=If%20you%20need,quality%20and%20resolution. is a solid route. If you need to save videos in the highest quality and resolution for offline use, this guide on converting video files is very thorough. It’s a more permanent, higher-fidelity option for your library.