Change Video Speed
Make a time-lapse from a long clip, or slow down an action shot. The audio is adjusted to the new speed without the chipmunk effect.
Free · No sign-up · Files stay on your device
How to use Change Video Speed
- 1Choose your video.
- 2Pick a speed, e.g. 2× or 0.5×.
- 3Click "Change speed" and download.
Features
- 0.25× to 4× speed
- Pitch-preserving audio
- Option to remove the audio
- H.264 MP4 output
- No upload
Natural-sounding audio
The audio is time-stretched rather than simply played faster, so voices keep their normal pitch at 1.5× or 2× speed.
Private, in-browser processing
This tool uses FFmpeg, the open-source engine behind most professional video software, running inside your browser. The first time you use it, the engine (about 30 MB) is downloaded once and then cached, so later conversions start straight away.
Frequently asked questions
Are my files uploaded?
No. Processing happens on your device with FFmpeg compiled to WebAssembly, so your video and audio never leave your computer or phone.
Why does it take a while?
Video processing is demanding, and your browser does it on your own device instead of a big server. Short clips take seconds; long or 4K videos can take several minutes. Keep the tab open until it finishes.
Does slow motion add frames?
No. Frames are shown for longer, so very slow speeds look less smooth than footage recorded in slow motion.