Slow down songs to practice without changing the key, speed up lectures, or shift the pitch in semitones without touching the tempo — then download the result.
Drop an audio file here, or browse
MP3, WAV, M4A, OGG… · stays on your device
🔒 Time-stretching and encoding run on your device — your music is never uploaded.
Drop a solo to 0.5×–0.75× at full pitch and your ears finally catch every note. The classic practice trick, no app needed.
Backing track too high? Shift it down two semitones and sing comfortably — the tempo doesn't move.
1.5× a recorded lecture without chipmunk voice, or make nightcore and slowed + pitched edits in two clicks.
Naively speeding audio up raises the pitch too. This tool uses time-stretching (WSOLA), which repeats or skips tiny grains of audio so tempo and pitch can change independently.
Small changes (0.75×–1.5×, ±4 semitones) sound very clean. Extreme settings introduce mild artifacts on complex music — that's true of any algorithm, including paid apps.
Duration scales with speed: a 4:00 song at 0.5× becomes 8:00, at 2× it becomes 2:00. Pitch changes don't affect length.