Step1: You can simply replace www. with ss in the url (when you play any video)
like Example:
Before: https://www.youtube.com/watch?v=WH8HAYHXLng
After add ss: https://ssyoutube.com/watch?v=WH8HAYHXLng
Step2: It will redirect you to this website
www.safefrom.netNote: In mobile https://m.youtube.com >> m. replace with ss
Advantages of using this "SS" trick: Free and download any video