For a journey, prepare the video before you leave
Find the film and open its viewing options. When the selected app supports downloading that title on your plan and device, choose the app's own download control. Wait for completion and check its downloads area while you still have a connection.
My List is a reminder, not a video file
Saving a movie here keeps its title easy to recover. It does not store the film on your phone. The same is true of a bookmark or home-screen shortcut. Those are useful planning tools, but they will not replace an offline copy during a flight.
Choose quality for the device you will carry
A high-quality download can need more space. Check the app's size estimate, remaining device storage and any viewing expiry it displays. If the app permits it, briefly test the downloaded film before travelling. Choose the audio and subtitles you need while the relevant options are available.
For reading picture-quality labels, see HD, 1080p and 4K. For moving your saved catalog choices, use My List backup.