Clear Video Watermark Online

Hey forum! I've been trying to save some hilarious cat videos and pet trick clips to share in our family group chat, but every time I download them directly through the app, that giant moving username bounces across the screen and blocks the funny details. My mom watches on an old tablet and gets super confused by the branding. Does anyone know a clean web tool that strips those annoying watermarks out instantly without messing up the video resolution?