Video Speed Changer
Speed up or slow down a video from 0.25x to 4x with sound kept in tune
Your files are processed on your device. The first use downloads a processing engine, which your browser then keeps.
Drop a video to speed up or slow down
or click to browseor tap to choose
Sound keeps its pitch
Large files (over 5 GB) may take longer or run out of browser memory
About Video Speed Changer
Makes a video faster (up to 4 times) or slower (down to a quarter). The sound is sped up or slowed down along with the picture and keeps its pitch, so voices do not turn into squeaks. The result is an MP4. Everything runs in your browser; the first use downloads a processing engine (about 25 MB).
Drop a video, pick a speed with the buttons or the slider and click Change speed. Download the result when it is ready. Your original file is not changed.
Slow motion cannot invent detail: a normal 30 frames per second clip played at half speed looks choppy, because the missing frames are not created. The new file keeps the original frame rate (up to 60) instead of doubling it. A video at 4 times speed is a quarter of the original length.
- Does the sound speed up too?
- Yes. The audio is sped up or slowed down with the picture and keeps its pitch, so voices do not become high or low.
- Why does my slowed-down video look choppy?
- Slowing a video does not create extra frames; it shows each existing frame for longer. For smooth slow motion you need a clip filmed at a high frame rate.
- What speeds are available?
- Anything from 0.25 times (four times slower) to 4 times (four times faster), using the presets or the slider.
- Does it change the frame rate?
- The output keeps the original frame rate, up to 60, so a sped-up clip does not become a huge 120 fps file.
- Is my video uploaded?
- No. It is processed in your browser. Only the video engine is downloaded once.
How to use Video Speed Changer
Drop a video, pick a speed from the buttons or drag the slider (0.25 to 4 times), and click Change speed. The picture and the sound are retimed together. Preview the result and download the MP4.
When to use it
Use it to shorten a long screen recording or time-lapse, to slow a short moment so it can be studied, to fit a clip into a time limit, or to make a tutorial easier to follow.
When not to use it
It does not create smooth slow motion: playing a normal clip at half speed shows each frame twice as long, so it looks choppy. It is also not a way to cut a clip; use Trim & Cut for that. Speeds beyond 4 times or below a quarter are not offered.
Tips for best results
A 10 minute clip at 4 times speed becomes 2 minutes 30 seconds. For slow motion, start from a high frame rate recording if your phone has one. If the sound is not needed, mute the video afterwards with Mute Video.
Limitations
The speed is one value for the whole clip; you cannot ramp it. The output frame rate stays at the original, up to 60 frames per second, so very fast clips drop frames. Sound keeps its pitch by chaining time-stretch steps, which can sound slightly processed at extreme speeds. The result is always an MP4 and the clip is re-encoded.
Privacy
The video is processed in your browser and is never uploaded. The first use downloads a video engine of about 25 MB from a public CDN, which the browser then keeps.
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