Use the YouTube app’s offline download feature if available in your region and for your account
Open the YouTube video in the app
Tap the Download button below the video
Choose the video quality if prompted
Wait for the download to finish
Open the Library or Downloads section to watch it offline
Use YouTube Premium if the download option is not available
Use the YouTube app on Android or iPhone for official offline downloads
Save videos only when you have permission and the content allows offline viewing
Avoid third-party downloader apps or websites unless you trust them and they comply with local laws and YouTube’s terms