Reverse a video
Play a clip backwards. Audio is reversed too, unless you turn it off.
Your file
Drop a file here, or click to choose
It stays on this device. Nothing is sent anywhere.
Settings
Keep it short
Reversing is the one job here that cannot be streamed. The last frame has to come out first, so every frame is held in memory until the whole clip has been read. A few seconds of 1080p is fine. A few minutes will run the tab out of memory and the job will die.
If you need a long reverse, trim it into short pieces, reverse each one, then merge them back in the opposite order.
The memory arithmetic
It helps to know roughly where the wall is rather than discovering it. Frames are buffered decoded, not compressed, so the file size on disk tells you very little. A 1920 by 1080 frame is about 3 MB uncompressed. At 30 frames a second, that is around 90 MB for every second of video, before the encoder's own working memory. Ten seconds is comfortably under a gigabyte and generally fine. Thirty seconds is not.
Resolution is the strongest lever, because it works on area: 720p frames are less than half the size of 1080p ones, and 480p frames are about a fifth. Running the clip through resize first will often turn a job that kills the tab into one that finishes in seconds, and for a reversed clip destined for social media the lower resolution is rarely the thing anyone notices.
The audio comes back too
With keep the audio track ticked, the sound is reversed alongside the picture, which is what makes reversed speech sound the way it does. If you are reversing footage to put music over it, untick it: the audio buffer is dropped, the job uses less memory, and the export is quicker.
What it is good for
The reliable uses are short and deliberate. A boomerang loop, where a clip is joined to its own reverse so it plays out and back. An object apparently assembling itself, which is just a demolition filmed forwards. A jump that becomes a landing. A pour that becomes a fill. All of these are two to four seconds of footage, well inside what this can handle, and all of them read better at that length anyway.
To build a boomerang, reverse the clip here and then join the original and the reversed copy with merge videos, in that order.
Common questions
How long a clip can I reverse?
Around 10 to 15 seconds at 1080p, or a minute at 480p. Trim first, then reverse.
The tab crashed. What happened?
It ran out of memory. Shorten the clip or lower the resolution with the resize tool first.