Audio Speed Changer
Speed audio up or slow it down, 0.25× to 4× — honest about pitch.
About this tool
A speed slider from 0.25× to 4× with preset chips, a live readout of the new duration AND the pitch shift in semitones, and WAV export. Processing is the browser's own resampler, on your device.
The pitch truth every speed tool should tell
This tool resamples: it plays the same samples faster or slower, so pitch moves with speed exactly as vinyl and tape did — 2× rises an octave (12 semitones), half-speed drops one. The readout shows the shift because honesty beats surprise. What about "change speed WITHOUT changing pitch"? That's time-stretching — a genuinely different algorithm (phase vocoders, transient detection) that trades artifacts for pitch stability, and a one-slider web tool that claims it cleanly is glossing over the warble. If listening speed is all you need, every podcast app and video player already time-stretches live without exporting anything. What resampling does BEST: the deliberate aesthetic (slowed-and-reverbed tracks are entire internet genres, and they're made exactly this way), transcription passes at 0.75× where the pitch drop doesn't matter, and sound design — everything gets deeper and heavier at half speed, which is how movie trailers make ordinary sounds monstrous. Echo and reverse are next door for the full tape-lab.
Frequently asked questions
Will the pitch change too?
Yes — this resamples, so 2× speed is +12 semitones, half speed is −12, shown live. Pitch-preserving stretch is a different algorithm with real artifacts; for listening, your podcast app already does it.
What's 0.75× good for?
Transcription and language practice — slow enough to catch every word, close enough to natural that the pitch drop doesn't distract.
How do I get the slowed-and-reverbed sound?
Set 0.75–0.85×, export, then run the result through the echo tool with a long delay and gentle feedback. That's genuinely the recipe.
Does processing lose quality?
The browser's resampler filters properly, so no artifacts beyond the physics of the speed change itself. Export is lossless WAV.