Video Speed Changer

How to use Video Speed Changer

1. Choose your video and set the speed multiplier.
2. Decide whether to keep, pitch-correct or drop the audio.
3. Process and download.
4. Slowing footage repeats frames — smooth slow motion needs high-frame-rate source.
5. Speed changes shift audio pitch unless corrected.
6. Processing runs in your browser; the file is never uploaded.

Speeding up drops frames; slowing down repeats them

Doubling the speed discards every other frame, which is fine for a screen recording and produces visible stutter in footage with motion. Halving the speed repeats each frame, so the result looks choppy rather than smooth — genuine slow motion requires footage shot at a high frame rate in the first place. 60fps source slowed to half gives you smooth 30fps output; 30fps source slowed to half does not.

What happens to the audio

Changing speed without correction shifts the pitch, which is the chipmunk effect. Pitch correction keeps the voice natural and is what podcast apps do at 1.5×. For a time-lapse you usually want the audio removed entirely, since sped-up ambient sound is unpleasant rather than atmospheric.

What each speed is for

1.25× to 2× for tutorials and lectures, where it saves real time and comprehension holds. 8× and beyond for time-lapse of a long process. 0.5× for reviewing technique — a golf swing, a keyboard shortcut, a mechanism — where you are looking at detail rather than wanting cinematic slow motion. Anything faster than about 3× makes speech unintelligible, so drop the audio there.