To loop a video on Android, open it in your gallery app and check the player’s menu (the three dots, usually top right) for a loop or repeat option. Whether one exists depends on the app and its version, so if you cannot find it, the dependable answer is to save a new video with the clip repeated inside it.
Android is not one app. Pixel phones and many others use Google Photos, Samsung phones use Gallery with Samsung’s own player, and other makers ship their own galleries. Their menus change often and neither Google nor Samsung documents a loop control in its help pages, so this guide sticks to what their official help confirms and is clear about the rest.
A looped file works everywhere: on a TV, in a message or in any player. You can make one in an editor such as CapCut, or loop the video in your browser with loop.video, which runs in Chrome on your phone without uploading the clip.