Change Audio Speed
Speed up or slow down an audio file, 0.5× to 2× — in your browser.
Select an audio file
Speed up or slow down an audio file — 0.5× to 2×. Pitch changes with speed. Runs in your browser.
Click to choose, or drop a file here
About changing audio speed
Slowing audio down makes a lecture or a language recording easier to follow and transcribe; speeding it up gets through a podcast or audiobook faster, or makes the "nightcore" effect. This tool changes the speed of any common audio file, 0.5× to 2×, in your browser.
It changes speed by resampling — playing the audio through an offline audio graph at a different rate — so it's clean and artefact-free, but the pitch moves with the speed: faster is higher, slower is lower. That's the same behaviour as a record played at the wrong RPM. Time-stretching that keeps the original pitch is a much heavier process and isn't done here.
The whole file is decoded into memory and re-encoded to MP3 or WAV, so very long recordings depend on your device's RAM. Nothing is uploaded at any point.
Supported files
Accepts MP3, WAV, M4A, AAC, FLAC or OGG. Produces an MP3 or WAV at the new speed.
Is my file uploaded?
No. The audio is decoded, resampled and re-encoded entirely in your browser.
Common problems
- The voice sounds like a chipmunk / too deep
- Expected — this method shifts pitch with speed. There's no pitch-preserving option here.
How to Change Audio Speed
- 1
Add your audio
Drop in the file.
- 2
Set the speed
0.5× to 2×. Pitch changes with speed.
- 3
Apply and download
Click Change speed and save the result.
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Change Audio Speed — frequently asked questions
Does the pitch change?+
Yes. This resamples the audio, so faster playback raises the pitch and slower lowers it — no time-stretch.
How far can I go?+
0.5× to 2×.
Is my file uploaded?+
No. It's processed in your browser.
What format do I get?+
MP3 or WAV.
Do you upload my files to a server?+
No — every tool here processes your files entirely on your device, and nothing is uploaded to a server. The only exception is the AI tools, which send the extracted text (not the file) to Claude to do their work.
Is there a file size limit?+
There's no artificial limit we impose, but since processing happens in your browser, very large files (500+ MB or 1,000+ pages) are limited by your device's memory rather than by us.
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