Change video speed
Shorten a lecture at 2× or slow a tutorial to 0.5×. Audio follows with “Keep pitch” so voices stay natural.
Settings
How to use
- 1
Add videos
Drop the videos whose speed you want to change.
- 2
Choose the speed
From 0.25× to 4×. With “Keep pitch” on, voices keep their natural pitch. Remove the audio if you do not need it.
- 3
Run and save
The video is re-encoded, so processing time scales with its length.
What happens when speed changes
Video frames are retimed and re-encoded; any frames beyond 60 fps are dropped, so even 4× stays smooth. Audio is time-stretched with WSOLA, preserving the pitch.
Because the video is re-encoded, processing time scales with its length. For long lectures, “Extract audio from video” followed by “Change audio speed” is often faster.
Frequently asked questions
What happens to the audio?
With “Keep pitch” on, voices speed up at their natural pitch. Turn it off to change the pitch too, or remove the audio for a silent video.
Is quality lost?
The video is re-encoded, so it changes slightly according to the Quality setting. At “High” or above the difference is negligible.
How long does it take?
With a hardware encoder, a fraction of the video’s length.
Slow motion looks choppy
Frames are held longer rather than interpolated, so at 0.25× each frame repeats four times. Frame interpolation is not supported.
Help us improve the service
If a conversion fails, sending us the circumstances helps us track down the cause. Knowing which devices and formats fail most often, and how long processing takes, lets us revise the supported formats and fix the bugs behind them. If you don't mind, leaving this on is a real help.
What is sent
The tool you used and the settings you chose (output format, quality, etc.), your device specs (GPU, memory, core count), the input format with a rough size, how many files succeeded or failed and how long it took, and the error type and details when something fails.
What is never sent
The files themselves, file names, text, subtitles or prompts you add to a video, and IP addresses. The data goes only to this site's own server, never to a third-party service.