Tools › Audio
Change audio speed and pitch
Slow down or speed up a song while keeping its key, transpose by semitones, make slowed or nightcore versions, or retune from 440 Hz to 432 Hz. Runs in your browser.
How it works
- Tempo is changed with WSOLA: the audio is cut into short overlapping grains which are lined up so their waveforms join without clicks.
- Pitch is shifted by stretching and then resampling with a band-limited filter, so voices stay clean and nothing aliases.
- Untick “keep the original key” for the classic slowed or sped-up sound where pitch follows speed.
Questions
How do I practice a song slower?
Use the Practice preset (0.75×). The key stays the same, so you can play along.
What does 432 Hz do?
It lowers the pitch by about a third of a semitone so that A sounds at 432 Hz instead of 440 Hz. Tempo doesn’t change.