Does changing the speed change the pitch of voices?

No. The audio is time-stretched with atempo, which keeps the original pitch at any speed from 0.25× to 4×.

Does it reduce video quality?

The video is re-encoded to H.264. On the High setting the difference is not visible. Slow motion can look steppy if the source frame rate is low.

What formats are supported?

MP4, MOV, WebM, MKV and AVI go in. An MP4 comes out. Files under about 300 MB and 1080p are comfortable.

Yes. No account, no watermark added, and nothing is sent to a server.

Free · No sign-up

Video Speed Changer

Make a video faster or slower, from 0.25× to 4×, with natural-sounding audio – no upload, no sign-up, no watermark added.

AI · Paid creditsAI Video Watermark Remover AI Video Eraser

No upload
No sign-up
No new watermark
MP4, MOV, WebM, MKV, AVI

Drop a video here or click to choose

MP4, MOV, WebM, MKV, AVI · best under 300 MB

Choose video

Loading video engine (0%)…

A real input to try

Start with an openly licensed sample.

An 8-second blue-mug MP4, shared by the remove-ai-watermarks project under Apache-2.0. The source maintainer documents Google Flow / Veo 3.1 Fast. Use the unchanged original to try this editing tool.

Input · video/mp4

This card shows an input, not a processed result. Loading it does not upload it or start a paid task.

Source: wiltodelta · Apache-2.0
Input: 1280 × 720 · 0.90 MiB

Attribution and modifications · Media facts and hashes

Speed up a tutorial so it fits a Short, turn a walk-through into a timelapse, or slow a sports clip down to see what happened. This tool changes the playback speed of both the picture and the sound.

Pick a factor between 0.25× and 4×. The audio is stretched with FFmpeg's atempo filter, so voices keep their normal pitch instead of turning into chipmunks or a low growl.

It all runs in your browser with FFmpeg WebAssembly. Your file never leaves your device, and the result is an H.264 MP4.

2× for tutorials and screen recordings

Speech at 2× is still clear with pitch preserved. Above 3× it becomes hard to follow, so consider muting instead.

Slow motion has limits

0.5× on 60 fps footage looks smooth. At 0.25× on 30 fps video, frames are repeated and motion looks steppy. Shoot at a high frame rate if you plan to slow down.

Trim first for long clips

Slowing down makes the file longer and heavier. Cut the section you need with the video cutter, then change the speed.

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A place for every edit.

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Keep the sound, without the video.