Change Speed
Speed a clip up or slow it down, picture and sound together.
- Add
- Adjust
- Make
- Keep
How to use this tool
- Add your files — drag them onto the page or choose them. They stay on your device.
- Pick the Speed — half speed for detail, double for talking heads, 8x to skim a recording.
- Choose the output format and run; audio is pitch-corrected where the target speed allows it.
- Press “Change speed” and download the results, individually or as one ZIP.
About this tool
Speed a clip up or slow it down, picture and sound together. Free and unlimited, and nothing is uploaded: it all runs in your own browser. Everything is analysed and produced on your own device — nothing is uploaded anywhere, and you can verify it: the tools keep working even offline.
Privacy & limitations
Files over roughly 2 GB, or long 4K videos, can exhaust the browser's memory — everything runs on your machine, so your machine is the limit. Extreme speeds (below 0.5x, above 2x) chain the audio processor, which is mathematically fine but audibly processy on music.
Last updated:
Frequently asked questions
Does the audio go squeaky?
No. The pitch is preserved: the sound is time-stretched rather than simply played faster, which is what makes speech at double speed still sound like the person talking. Very large changes are reached in stages for the same reason, because one extreme stretch sounds worse than two moderate ones.
Does speeding up drop frames?
The timestamps are rewritten rather than frames thrown away, so at double speed every frame is still there and the file simply plays through them twice as fast. At very high speeds the result has a high frame rate, which some players handle better than others.
Does slowing down make it smoother?
It makes it longer, not smoother. Half speed shows each original frame for twice as long, so motion looks stepped. Genuinely smooth slow motion needs footage shot at a high frame rate in the first place; nothing can invent frames that were never recorded.
Can I change the speed of audio on its own?
Yes. Audio files are accepted and get the same pitch-preserving treatment, which is how most podcast apps do it.