Edit · 09
Change Video Speed
0.25× slow motion to 4× timelapse — with audio that keeps its natural pitch, and a live preview before you render.
Drop your video here
MP4, WebM, MOV, MKV, AVI — or click to browse
drop works anywhere on this page
Speed up or slow down video — properly
The preview is instant: pick a speed and hit play, and your browser plays the video at that rate with pitch-preserved audio so you can judge the pacing before rendering anything. When you export, both the video timestamps and the audio are re-rendered on your device — video frames are retimed, audio is time-stretched — so the output plays at the new speed in every player, not just yours.
Pitch correction, explained
Speeding audio up naively raises its pitch (the chipmunk effect); slowing it lowers it. With Keep audio pitch natural on, we time-stretch instead, so a 1.5× lecture still sounds like the same person, just faster. Turn it off when you actually want the effect — deep voices for slow-mo, squeaky for comedy fast-forward.
Popular uses
- 2× screen recordings — halve the watch time (and roughly the file size) of tutorials and meetings.
- 0.5× sports and technique analysis — see the swing, the trick, the mistake.
- 4× timelapse from normal footage; 0.25× pseudo-slow-mo from 60fps clips.
On-device as always: a 20-minute recording starts rendering immediately, with live progress and a cancel button — no upload, no queue, no watermark.
FAQ
Does changing speed make voices sound like chipmunks?
Not with pitch correction on (default) — audio is time-stretched so voices keep their pitch. Turn it off for the classic effect.
What speeds are supported?
0.25× to 4×, with chips for common values and a live new-duration readout.
Will a 2× video be half the file size?
Roughly yes — half the duration at similar bitrate. Handy for sharing long recordings.
Is my video uploaded to change its speed?
No — rendering happens in your browser via WebAssembly. Nothing is transmitted.