Speed up lectures and podcasts or slow down music to practise, from 0.5× to 3×, with the pitch left exactly where it was. Everything runs in this tab.
Drop a file to process
Processed in your browser, entirely on your device or click to choose a fileIn this preview the file arrives inside a ZIP archive.
It keeps it. Pitch is the width of the waves, and the engine never changes that width; it only changes how many windows of audio land per second. A 440 Hz tone comes out at 440 Hz at every speed from 0.5× to 3×.
× is playback speed: 2× is twice as fast. % is the resulting length relative to the original: 50 % is half as long, which is the same thing as 2×. 200 % is twice as long, which is 0.5×. Use whichever you think in.
No fixed one. The whole recording is decoded into memory, so very long files depend on your device: an hour of stereo audio takes roughly a gigabyte of RAM while it is being processed. Phones may struggle beyond that; laptops rarely do.