Online Tool Store
Audio Speed Changer
Speed up or slow down an audio file using an overlap-add time-stretch that keeps pitch roughly steady, then download the result as a WAV. Runs entirely in your browser.
🔒 This tool runs entirely in your browser. Your files are never uploaded to a server.
How it works
- Choose an audio file.
- Set a speed between 0.5× and 2×.
- Click "Apply speed change" to process and preview the result, then download it as a WAV.
The method
Rather than just resampling (which shifts pitch along with speed), this reads overlapping, windowed chunks of audio at a rate proportional to the chosen speed, then reassembles them at a fixed output rate — an overlap-add time-stretch, so duration changes independently of pitch.
FAQ
Does the pitch change with speed?
It's designed to stay roughly the same — this uses an overlap-add time-stretch technique rather than simply speeding up playback (which would raise the pitch, like a sped-up tape). Extreme speed changes (well above 1.5× or below 0.7×) may introduce some audible artifacts.
What format does the result download as?
WAV — an uncompressed format that avoids any extra quality loss on top of the speed change itself.
How long does processing take?
It runs on your device and scales with the length of the audio — longer files take longer to process.
Is my audio uploaded anywhere?
No — decoding and processing both happen locally using the Web Audio API.
How we compare
| Feature | Online Tool Store | Media player playback speed | Desktop audio editors |
|---|---|---|---|
| Produces a downloadable file, not just playback | ✓ | ✗ | ✓ |
| No install | ✓ | ✓ | ✗ |
A media player's speed control only affects playback in that app. Audio Speed Changer gives you an actual file you can keep and share.