Set speed and export the video
No upload server is used; controls and exports stay in this browser.
Output timing follows the browser playback clock and local MediaRecorder.
Choose a local video file first.
The video plays at the chosen rate and is written frame-by-frame to WebM; no remote transcoding API is used.
Local preview
Create slow-motion and fast-forward versions locally
Adjust playback from 0.25x to 4.0x, render frames with Canvas and export a local WebM. Everything stays in the current browser tab.
3-step guide
- 1Choose a file
Load a browser-supported MP4/WebM file locally. - 2Set controls
Adjust the time, frame, speed or orientation controls. - 3Export locally
Render or capture, then download the Blob result.
Browser-only privacy
Video data, decoded frames and exports stay in memory or local Blob URLs in this tab.
Performance depends on device memory, browser codecs and video duration.
Frequently asked questions
Which speeds are available?
The control provides 0.25x, 0.5x, 1x, 1.5x, 2x and 4x.
Does audio follow the speed?
MediaRecorder follows the browser playback clock; audio behavior depends on the browser codec.
Why is the output WebM?
WebM is a browser-native format that MediaRecorder can produce locally in Chromium and compatible browsers.