Use the YouTube app’s offline download feature if available in your region and on your device
Open the video in the YouTube app
Tap Download
Choose a quality option
Wait for the download to finish
Open the YouTube app’s Library or Downloads section to watch it offline
If you need it in your phone gallery, use a screen recording app while playing the video if permitted by law and platform rules
Save the recording to your device’s gallery
Use YouTube Premium for official offline downloads within the app
Check the video owner’s permissions before saving or reusing any content
Avoid third-party downloader apps or websites unless you are sure they are legal and safe