How this speed changer works — and what it honestly does
Pick a preset from 0.25× to 4× or type a custom rate, and the tool replays your audio through an offline renderer at the new speed, producing a file that is proportionally shorter or longer. This is resampling — the digital equivalent of playing a record at the wrong RPM — so pitch changes with tempo. Sped-up voices go chipmunk; slowed-down audio drops into slow-motion rumble. That is not a bug, it is the physics of the method.
Pitch-preserving time-stretch is a different beast: it needs a phase vocoder or similar DSP that analyses and rebuilds the signal, with artifacts of its own. This tool deliberately keeps things simple and artifact-free within its method. And if your goal is just listening faster — a lecture, a podcast — you may not need an export at all: the playback-speed control in your browser’s native player and every podcast app already preserves pitch.
Good uses for pitch-shifted speed changes
- Slowing a riff to 0.5× to transcribe it — it lands exactly an octave down, so notes map cleanly.
- Creating deliberate chipmunk or slowed-reverb style effects.
- Slowing dictation slightly (0.75×) where the pitch drop is mild and clarity wins.
Combine with the other audio tools
Renders export as 16-bit WAV at the original sample rate, previewable on the page before download. Cut the section you need first with the Audio Trimmer to keep files small, and if the result comes out quiet, run it through the Audio Volume Booster afterwards.