Change video speed
Speed up or slow down, with the audio kept at a natural pitch.
Your file
Drop a file here, or click to choose
It stays on this device. Nothing is sent anywhere.
Settings
What happens to the sound
Naively speeding up audio makes everyone sound like a chipmunk. The atempo filter used here stretches time without shifting pitch, so a 2× speed-up sounds like someone talking quickly rather than someone inhaling helium. Above 2× the filter is chained, which is why 4× still sounds reasonable.
Slowing down
Slow motion below 1× repeats frames rather than inventing new ones, so a 30 fps clip at quarter speed still shows 30 distinct pictures per second of original footage. It will look stepped. Genuinely smooth slow motion needs footage shot at a high frame rate to begin with.
Common questions
Will 4× speed sound distorted?
A little, on music. Speech holds up well because the filter is applied in stages, each within its comfortable range.
Why did it fail when I ticked 'keep audio'?
The input probably has no audio track. Untick it and run again.