Free tool
Reverse video online for free, with a boomerang option
Reverse video so it plays backwards, or make a boomerang that plays forwards and then backwards, ending where it began.
Your video
Drag a file here, paste it, or choose one.
.mp4, .mov, .webm, .mkv. Up to 500 MB.
Reverses up to 60 seconds at a time. Less for 1080p and 60 fps, see below.
Your video never leaves your browser. It is reversed on this machine.
Result
Worked example
Measured on our own 26 second whiteboard explainer at 1280 by 720, as a boomerang with the sound reversed.
Source
4.2 MB, 0:26
Boomerang
1.4 MB, 0:53
Twice as long and a third of the size, because the explainer is mostly still drawings and crf 23 spends few bits on a frame that barely changes. At 720p and 30 fps this tab reverses up to 33 seconds at a time.
1. Drop in a video. 2. Pick reverse or boomerang. 3. Choose the sound. 4. Download the MP4.
What Interlace does
Show how it works, one step at a time.
- Write one sentence or upload a document
- Interlace draws each step as its own scene
- Voice and on-screen text in 28 languages from one source
Real Interlace output, unedited. Shown silent and sped up.
Your file
pour-shot.mp4
6 s, made into a boomerang
Questions
Asked and answered
No. The clip is reversed by ffmpeg compiled to WebAssembly, inside this browser tab, and the MP4 is saved straight to your machine. Nothing is sent to a server.
Reversing cannot write anything until it has read the last frame, so it keeps every decoded frame of the stretch in memory, and ffmpeg in a browser tab can use at most 2 GB. We measured where it breaks: a 1280 by 720 clip at 30 fps reversed fine at 45 seconds and failed at 50, and a 1920 by 1080 clip at 60 fps reversed fine at 10 seconds and failed at 12. The page stays at three quarters of that, about 33 seconds of 720p at 30 fps, 15 seconds of 1080p at 30 fps, or 7 seconds of 1080p at 60 fps. For a longer clip, pick which stretch to reverse, or shrink the video first with the resizer.
You choose. Reverse it and the sound runs backwards with the picture, so speech turns into gibberish. Keep it forwards and the original sound plays normally under the reversed picture. Mute drops the sound track altogether. A video with no sound track comes out silent whatever you pick.
The clip plays forwards, then the reversed copy is joined straight after it, so the result is twice as long and its last frame is its first. Set the video player to loop and it never visibly restarts. With the sound kept forwards, it plays twice.
Nothing can be written until the last frame has been read, because the last frame is the first one out. So the bar waits while the whole stretch is decoded into memory, then moves as the reversed frames are encoded.
Turn this into a video
Create an account and start from a document, script, or prompt.