This website is safe. I visited this website plenty of times and I also use this site to get my music from here. It's free and easy to use. This works by entering a youtube url, then you press the "Convert Video" button, then it will start to convert the video into a playable audio file. When it's done downloading, click the "Open file when done." button.
Be careful with places like this. They usually contain viruses/trojans/pop ups.
One of the detected URLS: https://www.virustotal.com/url/5a3c06f82203760990cbb1ce56100a622e38fc3082a28b88f0a45ec237881172/analysis/
Sobre este site
Download your favorite YouTube videos as mp3 files without registration.