Speed Video
Speed Video changes a clip's playback rate — from a quarter speed for slow-motion detail to four times faster for a quick recap or timelapse feel. The audio is kept pitch-correct as the speed changes, and a live preview shows the new pace before you export. Everything is processed on your device.
Add your video
The file is read by your browser and stays on your device — there is no upload step.
Your video
The work runs in this tab. Nothing is sent anywhere, and the download is generated locally.
How to use Speed Video
- 01Upload
Load your clip
Drop the video in and it plays in the preview at normal speed.
- 02Customize
Set the speed
Pick a preset like 0.5× or 2×, or fine-tune anywhere from 0.25× to 4× with the slider. The preview updates live.
- 03Process
Export
Export to render the sped-up or slowed-down clip and download it.
What changing speed does
Plays the clip faster or slower by changing how long each frame is shown. Speeding up shortens the clip proportionally; slowing down lengthens it.
What does not change
Resolution and framing. What does change is smoothness: slowing footage below about half speed shows the gaps between frames as judder, because the frames to fill them were never recorded. Shoot at a high frame rate if you know you will slow it down.
Supported formats
- MP4
- MOV
- WebM
- AVI
- MKV
- Maximum file size —
- bounded by your device's memory
- Processed by —
- FFmpeg (WebAssembly), on your device
Your file, and what the page does
Your file is never uploaded. Speed Video reads it into this browser tab and processes it with FFmpeg compiled to WebAssembly on your own device. There is no upload endpoint in the application and no copy on any server — closing the tab discards it.
That is also why processing takes longer here than on a site that uploads: your device is doing the work rather than a rack of servers. The trade is that the file never leaves it.
What the page does send or fetch
- The processing engine, once
- The first time you use any video or audio tool, the browser downloads the FFmpeg WebAssembly build (~30MB) from the jsDelivr CDN and reuses the cached copy afterwards. That is a file coming to you — no part of your own file is in the request.
- Ads on the page
- The site is funded by advertising, so the page loads Google AdSense. That carries the usual web basics — IP address, browser, referring page — as on any ad-supported site.
- An anonymous usage counter
- When Speed Video finishes we record that the tool ran, whether it succeeded and how long it took. No file data, no identifier, no cookie.
Your file is not on that list. How this works.
Frequently asked questions
No. The audio is time-stretched with atempo, so voices and music keep their natural pitch at any speed.
From 0.25× (four times slower) to 4× (four times faster), with presets at 0.5×, 1×, 1.5× and 2×.
Yes — slowing a clip down makes it longer and speeding it up makes it shorter, in proportion to the rate you choose.
Yes — Speed Video is completely free. There's no account, sign-up, watermark or limit.
No. It runs in any modern browser — Chrome, Edge, Safari, Firefox, Brave — with nothing to download or install.
Looking for something else?
- Only the audio pitch is the problemPitch Shift
- It is too long — cut instead of speedTrim Video
- It should play backwardsReverse Video
Edit any media with a right-click
Add Dexta Studio to Chrome and open any image, video, audio or PDF straight into the right tool — free, nothing uploaded.