Extract/Download video from Youtube to .avi or .mp4

Clip Converter is a free online media conversion application, which allows you to extract part/all, convert and download audio or video from URL to common formats (avi, mp4, mp3). Currently supported services: Direct Download, YouTube (HQ and HD), Dailymotion (HQ) and more.

Other online options:
https://catchvideo.net/
https://ddownloader.com/
https://keepv.id/

Other offline options:
4K Video Downloader