You can download videos that you’ve already uploaded. If you haven’t uploaded the video yourself, you can’t save it to a computer. You can download videos from the YouTube app to your mobile device only.
How do I download and save a YouTube video?
Right-click the video in your browser, then click Save video as in the resulting drop-down menu. The video will begin downloading onto your computer as an MP4 file with the name “videoplayback”. Select a location and click Save. This downloads the video to your computer.
Can you download YouTube videos to watch offline?
Launched in 2014, YouTube’s offline feature allows Android and iOS users to save YouTube videos to their device for later consumption. These videos can be downloaded via mobile data or Wi-Fi network. Any video downloaded can only be played offline for up to 48 hours.