Change Video Speed Online Free

Frequently asked questions

How do I change video speed online?

Upload your video (MP4, WebM, or MOV). Choose a speed: 0.5x (slow motion), 0.75x (slightly slow), 1.5x (faster), or 2x (timelapse). Click "Change speed". FFmpeg.wasm re-encodes the video and audio at the chosen speed. When done, download the result. Your file never leaves your device.

Are my videos sent to a server?

No. Processing runs entirely in your browser using FFmpeg.wasm. Your video never leaves your device.

What do the speed options mean?

0.5x plays the video at half speed (slow motion). 0.75x is slightly slowed. 1.5x is 50% faster. 2x is double speed (timelapse). Both video and audio are adjusted so they stay in sync.

Why does it take a while to process?

Changing speed requires re-encoding the video and audio. FFmpeg.wasm runs in the browser, so speed depends on your device. A progress bar shows the status. Longer or higher-resolution videos take more time.

What format is the output?

The output is MP4 (H.264 video, AAC audio), which is widely supported. The original format (e.g. WebM, MOV) is converted to MP4 for the speed change.

Does it work on mobile?

Yes, in browsers that support WebAssembly. Re-encoding is CPU-intensive, so on phones it may take longer; short clips work best.

Can I use custom speed values?

This tool offers four fixed speeds (0.5x, 0.75x, 1.5x, 2x) that work reliably with audio sync. For other values you would need a desktop video editor.

Is there a file size limit?

There is no fixed limit. Very large or long videos may use a lot of memory and take a long time. Practical limits depend on your device.

Why change video speed?

Slow motion (0.5x, 0.75x) is useful for sports, tutorials, or dramatic effect. Faster speed (1.5x, 2x) is useful for timelapses, quick summaries, or fitting more content in less time.

Does it work in all browsers?

FFmpeg.wasm requires a modern browser with WebAssembly. Chrome, Firefox, Safari, and Edge (recent versions) work.