⏩ Change Video Speed

Change video speed from 0.5x (slow motion) to 2x (fast motion). Both picture and audio speed change together, so speech stays in sync.

Runs entirely in your browser with FFmpeg.wasm. No upload, no account, no video stored anywhere, and no watermark added by this site.

📁 Drop a video here, or choose a file

MP4, MOV, WebM and other common video files. One file at a time. Files are processed in your browser only — nothing is uploaded.

Choose video

Speed

Before you press Process: the video engine is about 32 MB and downloads only when you press Process — never on page load. Your video never leaves this device. No account, no artificial limit; speed depends on your device and browser.

How to use it

Choose a video file.
Choose a speed: 0.5x, 0.75x, 1.25x, 1.5x or 2x.
Press Change Speed.
Download the MP4 at the new speed.

Supported formats and limitations

Your video never leaves your device. Processing runs in your browser with FFmpeg.wasm; there is no upload, no account and no server copy.
The video engine (about 32 MB) is downloaded only after you choose a file and press Process — never automatically when the page loads.
There is no artificial usage limit and no account. Real speed and maximum size depend on your device and browser: large or long videos are slower and may run out of browser memory. A warning is shown for very large files, but no file is hard-blocked for size alone.
Speed changes re-encode to H.264 and AAC. The output duration is the original duration divided by the speed factor.
Very slow speech (0.5x) and very fast speech (2x) are harder to understand. That is a property of speed change, not an error.
No artificial usage limit: capacity depends on your device and browser. Large or long videos are slower and may run out of browser memory.

Frequently asked questions

Does the audio stay in sync?

Yes. Picture and audio are both scaled by the same factor.

Can I speed up only part of a video?

Split or trim the part first, change its speed, then merge the parts back together.

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