Want to watch YouTube videos offline on your phone or Laptop? Here’s how to download YouTube videos.
Is it safe to download YouTube Videos from third-party sites?
YouTube’s official apps are the only most safe medium for you to download videos.
How to download videos with an online YouTube video downloader
I tried a few of these and liked YT1s.com. You can open the site, paste the video URL or type the name, and tap the red convert button. The site will show you a bunch of videos and related videos, click on the one that match your search and the site will ask you for the format (Mp4, Mp3, 3gp with resolutions. To download the video, tap on Get link and tap on the green download button to download the video.

YouTube Premium
Residents outside the United States, can still download YouTube videos without subscribing to YouTube Premuim. Check the list supported countries to see where downloading videos works without paying for YouTube Premium.
Open any video and tap the Download button below the title of the video. Select the video download quality, and tap Download again to save it for offline viewing.
You can also check all your downloaded videos by accessing the Library on YouTube app and tap on Downloads.