Open the video in a video editor or playback app that supports speed control
Find the speed or playback rate setting
Reduce the speed below 1x, such as 0.5x or 0.25x
Apply the change to the entire video or selected clip
Export or save the slowed-down video
Use a mobile app with a slow-motion or speed adjustment tool
Use desktop software like iMovie, Premiere Pro, DaVinci Resolve, or CapCut
Use online video editors that offer speed controls
If needed, adjust audio separately to avoid distortion
Preview the result before saving the final version