Reverse a video (play backwards)
Import a video to get a version where the picture and sound play backwards, from the last moment to the first. Fully local processing using an ffmpeg engine loaded in your browser.
Warning: reversing requires keeping the entire video in memory in the browser. This tool works best for short videos (under 30 to 60 seconds); long or large videos may fail due to lack of memory, or crash the tab.
How it works
The tool loads an ffmpeg engine compiled to WebAssembly into your browser, then applies the reverse (for the picture) and areverse (for the sound) filters to rebuild the video from the last frame to the first. The result is an MP4 file with picture and audio synchronized in reverse.
Why do long videos sometimes fail?
To reverse a video, ffmpeg has to decode and keep all the frames in memory before it can write them back in reverse order — unlike a simple filter applied frame by frame on the fly. In a browser, the memory available to the tab is limited, so a long, high-resolution or high-frame-rate video can exceed this limit and cause a failure or a significant slowdown.
How do I process a video that's too long?
First split your video into shorter clips (for example with a video trimming tool), then reverse each clip separately. You can also reduce the resolution or duration before trying the reversal to limit memory use.
Total privacy: the video is processed only on your device, and no data is sent to an external server.