Change audio speed

Double-speed lecture, half-speed practice track — tape-style resampling moves pitch with tempo, exactly like a tape deck.

Tools used in this guide

The job

Sometimes you want it faster, sometimes slower — and pitch shifting along is the point: musicians learn licks at half speed, podcasts get tight at 1.5×.

Resample

Choose the file, set the factor (0.25–4×), export WAV. The tool resamples by linear interpolation — new length is old ÷ factor, and pitch shifts an octave per doubling.

2× plays an octave up, 0.5× an octave down — tape-style, not chipmunk-free time-stretch.
1.25× on a speech file keeps it intelligible; 4× is a test, not a listen.

Worked example

A 10-minute guitar tutorial at 0.75× becomes a 13-minute practice pace with pitch a perfect fourth lower — playable along on a downtuned instrument.

Where it stops

Linear interpolation is honest but not hi-fi — extreme factors alias on bright material. There is no pitch-preserving mode; for that you need a real time-stretch algorithm. Files up to 200 MB that decode within a 256 MB PCM budget (about 12 min stereo at 44.1 kHz); the resampled output is held to the same budget and exports as 16-bit WAV.