Reverse a Video

Play a short clip backwards, with the audio reversed, kept forward or muted. Capped at 30 seconds and 100 MB because reversing holds every frame in memory.

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Drop your file here (.mp4, .mov, .m4v, .webm)

🔒 Private by design: your files are processed locally in your browser and never uploaded to any server.

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The one filter that cannot stream

Most video processing is a conveyor belt. Frames arrive, get scaled or cropped or recoloured, and leave, and the tool never needs to hold more than a few at a time. That is why you can crop a two hour film in a browser tab.

Reversing breaks that model completely. The first frame of the output is the last frame of the input, so nothing can be written until everything has been read and decoded. The entire clip lives in memory simultaneously, uncompressed, and uncompressed video is enormous: a single second of 1080p at 30 frames per second is roughly 93 megabytes of raw pixels before any of the surrounding overhead.

The engine here runs single threaded, without the cross-origin isolation that would allow threads, inside a heap that is bounded by the browser. There is no clever way around this. So the tool measures the clip first and refuses up front rather than freezing your tab and losing the work.

Reversing a short clip

  1. Drop your video on the box or use Choose a file. MP4, MOV, M4V and WebM are accepted.
  2. Choose an Audio option. Reverse audio too (plays backwards) keeps sound in step with the picture, Keep audio playing forward does not, and Remove audio (silent video) drops it.
  3. Click Reverse a Video. The clip is probed first, so an over-limit file is rejected in a second or two rather than after a long wait.
  4. If it passes, the encode runs and the progress bar tracks it.
  5. Download the result, named after your file with a reversed suffix and an mp4 extension.
  6. Process another clears the queue.

The probe step is doing two jobs at once. It reads the duration for the limit check, and it reports whether there is an audio stream at all, which decides how the encoder is invoked.

Two limits, because they fail differently

Thirty seconds and one hundred megabytes, both checked, either one enough to stop the run.

Duration alone would not be sufficient. A 4K clip at a high bitrate can be huge in decoded frames while comfortably under half a minute, and that is precisely the file that exhausts memory. File size alone would not be sufficient either, since a heavily compressed long clip can be modest on disk and vast once decoded.

The refusal is built with the specific limit and your actual figure in it, so a 47 second clip is measured as 47 seconds against a 30 second limit. You will not read that sentence, though, and it is worth knowing why: the shell around this tool replaces any thrown error with one fixed generic apology, so the detailed wording goes to the browser console and the screen shows only that something went wrong. When a clip is refused, check it against both numbers rather than looking for the reason on the page. Duration is skipped when the probe cannot determine it, which happens with some containers and with damaged files, and the size check carries the load in that case.

Three ways to treat the sound

Reversed audio is the default and the obvious one. Speech becomes unintelligible, music becomes eerie, and a pouring liquid becomes something being drunk. It stays in sync with the picture because both streams are reversed together.

Keeping the audio forward produces something stranger and genuinely useful: the picture runs backwards over the original soundtrack. For a reversed visual over a music bed, this is what you want, and it saves you a separate step to re-attach the audio afterwards.

Muting is for the case where you are going to add sound later, or where the original audio is just room noise you do not need. It is also what happens automatically when the input has no audio stream, since there is nothing to reverse or keep.

What to run before and after

The realistic workflow is to shorten first. Trim Video cuts the clip down to the moment you actually want to reverse, which both gets you under the limit and saves you encoding frames you were going to discard. Compress Video helps with the size limit if a short clip is still too heavy.

Afterwards, MP4 to GIF turns a reversed clip into a loop for a chat or a forum post, and Loop Video repeats it. For a forward-then-backward bounce, reverse a copy and join the two. If it is only the soundtrack you want played backwards, Reverse Audio does that on its own without touching any pixels. The rest is on the video tools hub.

Frequently asked questions

Why is there a 30 second limit?

Because reversing is the one video operation that cannot be streamed. To emit the first output frame the filter must already hold the last input frame, which means the entire decoded clip sits in memory at once. The engine here runs single threaded inside your tab with a bounded heap, so a long clip does not slow down, it crashes the tab. The cap turns that crash into an immediate refusal instead, before any encoding starts.

There is also a file size limit?

Yes, 100 MB, checked alongside the duration. Both matter because they fail differently. A short but very high resolution clip can be enormous in decoded frames while staying under 30 seconds, and a long low resolution one can be small on disk. Exceeding either limit stops the run before any encoding starts. Internally the refusal names which limit you hit and by how much, but the shell around this tool replaces any thrown error with one fixed generic sentence, so that detail never reaches the screen. If a clip is refused, check it against both numbers.

What if the tool cannot read my clip's duration?

Then only the size limit is enforced. Some containers and damaged files report their length as unavailable, and refusing to process a video purely because its length could not be probed would be the wrong call. The size check still applies, so the memory risk is still bounded.

What does keeping the audio playing forward actually give me?

A clip whose picture runs backwards over its original soundtrack, deliberately out of sync with the action. It sounds like a mistake described that way, and it is exactly what you want for a reversed visual gag over a piece of music, or for any edit where the audio is a bed rather than a recording of the scene.

What happens if my clip has no audio track?

The audio setting is ignored and the output is silent. A clip with no audio stream cannot have one reversed or kept, and asking the encoder to map a stream that does not exist is an error rather than a no-op, so that case is detected during the probe and handled by simply not requesting audio.

Which format do I get back?

MP4, whatever went in. Reversing rewrites every frame so a re-encode is unavoidable, and once that is true, standardising on the most widely playable container costs nothing. Video is encoded with H.264 at a quality-leaning setting, audio as AAC at 192 kbps, and the file is written so it can start playing before it has fully downloaded.

How do I reverse something longer than the limit?

Cut it down first. Trim the section you actually want, reverse that, and if you need a long reversed sequence, reverse the pieces separately and join them back in the opposite order. That is more work, but it is the only approach that fits inside a browser tab.

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