Change Video Speed
Media & Video StudioSpeed up or slow down footage, keeping audio in sync.
What is Change Video Speed?
Change Video Speed lets you slow footage down for dramatic slow motion or speed it up into a quick time-lapse, right in your browser. Drag a single slider from 0.5× to 2× and the tool retimes both the picture and the audio together, keeping them in sync and preserving the audio's pitch. Because it runs locally with in-browser FFmpeg (WebAssembly), your video is never uploaded.
How to use Change Video Speed
Add your video
Drag a file onto the drop zone or click to browse. MP4, MOV, and WebM work best. The in-browser video engine loads in the background while you choose a speed.
Choose a speed
Drag the slider between 0.5× and 2×. 0.5× is half speed (slow motion), 1× is normal, and 2× is double speed. The audio is retimed to match and its pitch is preserved, so voices don't turn chipmunk-high.
Change the speed
Click Change speed. The video is re-encoded with H.264 at the new timing and the audio is stretched or compressed to stay perfectly in sync with the picture.
Preview and download
Watch the retimed clip in the built-in preview, then download the MP4. Everything is processed on your device, so nothing is uploaded.
Common uses
- Slow a sports or action clip into smooth slow motion for review
- Speed up a long screen recording or tutorial to keep it snappy
- Turn a slow pan or build sequence into a quick time-lapse
- Fit a clip into a tighter length limit by speeding it up
- Slow down a demo so viewers can follow each step
- Create a dramatic slow-mo highlight without pitch-shifting the audio
Why choose FreeTools
100% private
Your files are processed inside your browser and are never uploaded to a server.
Free, no account
No sign-up, no watermark, no paywalled “premium” tier. Just open a tool and use it.
Instant
No upload, no queue, no server round-trip — work starts the moment you drop a file.
Runs in your browser
Built on open web standards. Works on any modern desktop browser, nothing to install.
No upload size caps
Nothing leaves your device, so there’s no server file-size limit — only your machine’s memory.
Yours to keep
Results download straight to your device in clean, standard file formats.