I rely on Easy Youtube Video Downloader Express to extract mp3 from videos everyday. I have found it very reliable and convenient, having a one-click Download button underneath the video. It can take up to 30 seconds to extract the mp3, but so far it has proved to be the most stable and reliable application that I have used for this task.

Recently, (April 2023), the Download button disappeared, due to Youtube altering their code again, apparently to prevent easy downloading of videos.

If this happens to you, don't despair! I emailed Dishita and got a reply in about 2 hrs, which was a pleasant surprise, as I didn't expect such a prompt response! I was offered the new version 18.4 to test, and it has solved the Download Button problem.

You have to have the 'PRO' Key activation for downloading mp3 and 1080p, though, but that's not really a problem as it's only a one-off donation.