Change Video Speed Online

Change video speed online for free with a fast, private video speed changer that runs entirely in your browser. Load any MP4, WebM or MOV clip, then speed up video at 1.25x, 1.5x or 2x, or slow down video at 0.75x or 0.5x for a smooth slow-motion look. Both the picture and the audio are retimed together so everything stays in sync, and the result is exported as an MP4 you can download instantly. Because all processing happens locally with ffmpeg.wasm, your video is never uploaded and never leaves your device. It is a simple way to make a fast-forward video, a time-lapse feel or a slow-motion edit without installing any software.

🔒 100% private — files never leave your device

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How to use

  1. Select or drop a video file (MP4, WebM, MOV and more).
  2. Pick a speed: 0.5x, 0.75x, 1.25x, 1.5x or 2x.
  3. Click Apply and let the in-browser engine retime the video and audio.
  4. Download your new sped-up or slowed-down MP4.

Frequently asked questions

What video formats can I change the speed of?

You can load common video files such as MP4, WebM and MOV. Whatever you drop in, the tool always exports a standard MP4 running at your chosen speed.

Is my video uploaded to a server?

No. Nothing is ever uploaded. The speed change runs 100% in your browser with ffmpeg.wasm, so your video stays on your device and never leaves it.

Does the audio stay in sync when I change the speed?

Yes. The audio is retimed by the same factor as the video using the atempo filter, so picture and sound stay perfectly in sync. Silent clips like screen recordings are handled too.

Which speeds can I choose?

You can pick 0.5x or 0.75x to slow a video down, or 1.25x, 1.5x or 2x to speed it up. The output is always saved as MP4.

Is there a file size or length limit?

There is no fixed limit, but because everything runs in your browser, very large or long videos use more memory and take longer. Shorter clips on a desktop browser process fastest.

Why does the first run take a little longer?

The first time you use a video tool, the ~30MB ffmpeg engine downloads once and is then cached. After that it runs offline and later speed changes start much faster.

About this tool

Free online video speed changer: speed up or slow down MP4, WebM or MOV at 0.5x, 0.75x, 1.25x, 1.5x or 2x. Runs 100% in your browser with no uploads.

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