Video speed changer
Speed a video up or slow it down — pick a factor and download the result, audio included.
Timelapse feeling, slow-motion feeling
Speeding up compresses time: a 2x pass turns four minutes of tidying, sketching or cooking into two, and the brisk movement itself reads as energy. Slowing down does the opposite — 0.5x gives a jump, a pour or a golf swing room to be looked at properly. The range here runs from 0.5x to 2x, which covers most jobs; for a stronger timelapse there is an honest workaround: run the clip through at 2x, then feed the result straight back in for another 2x pass, and you have 4x. Each pass re-encodes, so stop when it looks right rather than stacking passes for sport.
The sound comes along — decide if you want it
The audio changes speed with the picture, pitch included, and while a sped-up voice can be part of the joke, slowed-down audio is rarely what anyone wants under slow motion — a deep, smeared drone tends to spoil the elegance of the shot. The practical fix is to treat sound as a separate decision: render the speed change first, judge the result, and if the warped audio bothers you, lay music over it with /video-audio-replacer. Sports clips, in particular, almost always end better with a clean track than with slowed crowd noise.
What file you get back
Your browser does the recording, so the container depends on where you are: Chrome and Firefox typically produce WebM, Safari produces MP4, and the download button always names exactly what was made — nothing arrives mislabelled. If the platform you are uploading to insists on MP4 and you received WebM, one pass through /video-converter fixes that without re-editing anything. Rendering happens in real time (a 2x speed-up of a minute-long clip takes about half a minute; a 0.5x slow-down takes two). On the free tier, source videos up to 1.5 minutes and 60 MB are included and the output carries a small watermark; a day pass or unlock lifts the limits and removes the mark.
Why this takes as long as it takes
The video actually plays at the new speed while it's recorded — a 2x speed-up still needs half the original duration in real time, a 0.5x slow-down needs double. The audio speeds up or slows down together with the video, exactly like playing a record faster or slower — pitch and speed are linked, that's expected here.
Does the audio change speed too?
Yes, together with the video — and its pitch shifts along with it, the same way speeding up a record raises its pitch. If you need speed and pitch changed independently, that's a different kind of processing.
Is my video uploaded anywhere?
No upload happens at any stage. The re-timed clip is played back and captured entirely on your own machine, so the footage stays with you from start to finish.
