Use the YouTube app’s offline download feature if you have YouTube Premium
Open the YouTube app and sign in
Open the video you want to save
Tap Download
Choose the video quality if prompted
Wait for the download to finish
Open Library or Downloads in the YouTube app to watch offline
If the video is your own, open YouTube Studio and download it from there
If the creator allows it, use the video’s offline options in supported apps
Avoid third-party download apps or websites unless you have permission and they comply with YouTube’s terms