Does changing tempo also change the pitch?

Yes, with this tool. Speeding up also raises the pitch; slowing down lowers it. True time-stretching without pitch change requires a phase-vocoder algorithm.

What speed range is supported?

0.25× (quarter speed) to 4× (four times speed). At 0.25× a 1-minute clip becomes 4 minutes; at 4× it becomes 15 seconds.

Is the audio uploaded to a server?

No. Speed changing uses the Web Audio API OfflineAudioContext. Everything runs locally in your browser.

Can I use this to listen to a lecture faster?

Yes. Set speed to 1.5× or 2× to save time on spoken content. Bear in mind that pitch will rise accordingly.

Tempo Changer

Speed up or slow down any audio file from 0.25× to 4× using the Web Audio API — runs entirely in your browser, no upload or account required.

100% client-side · no upload

Audio file

Settings Speed multiplier (0.25× – 4×)

Load a file to begin.

How to use

Choose your audio file. Any format your browser can decode is accepted.
Enter the speed multiplier: 1.5 plays 50% faster, 0.5 plays at half speed (range 0.25× – 4×).
Click Apply Speed Change and download the WAV output.

Related tools

More ways to use this tool

Frequently Asked Questions

Does changing tempo also change the pitch?: Yes, with this tool. Speeding up also raises the pitch; slowing down lowers it. True time-stretching without pitch change requires a phase-vocoder algorithm.
What speed range is supported?: 0.25× (quarter speed) to 4× (four times speed). At 0.25× a 1-minute clip becomes 4 minutes; at 4× it becomes 15 seconds.
Is the audio uploaded to a server?: No. Speed changing uses the Web Audio API OfflineAudioContext. Everything runs locally in your browser.
Can I use this to listen to a lecture faster?: Yes. Set speed to 1.5× or 2× to save time on spoken content. Bear in mind that pitch will rise accordingly.

Last updated: 2026-05-20 By jarvisbox