Audio Speed Changer (Keep Pitch)
Speed up or slow down audio from 0.5× to 2× — keep the original pitch (time-stretch) or change it like a tape — for podcasts, lessons and practice.
How to use
- 1Add audio and choose the speed.
- 2Keep 'Preserve pitch' on for natural voices, preview, then download.
How it's calculated
Pitch-preserving speed changes use WSOLA time-stretching (overlap-add of best-matching windows). Without it, audio is resampled, which changes pitch too.
Frequently asked questions
Will voices sound natural?
Between 0.75× and 1.5× speech sounds natural with pitch preservation on; extreme settings add a slight echo.
How do I slow down a song to learn it?
Choose 0.5×–0.8× with pitch preserved, so notes stay in tune.
Can I do the 'nightcore' effect?
Turn pitch preservation off and speed up to about 1.25×.