How to Change Video Speed Online
Steps
Open FastEdit
Go to fastedit.net. No installation or account required. The editor runs in your browser.
Drop your video file
Drag and drop your video (MP4, MOV, WebM, MKV, or other formats) onto the editor. The file loads locally. Nothing is uploaded to a server.
Add a speed region on the timeline
Open the speed panel and add a speed region to the timeline. This defines a segment of your video where the playback speed will change.
Set speed and position the region
Drag the region to cover the segment you want to affect, and set the speed: 0.25x, 0.5x for slow motion, 2x, 3x, or 4x for fast-forward. You can add multiple speed regions for different parts of the video.
Preview the result
Scrub through the timeline or play back the video to check the speed transitions. Adjust region boundaries and speed values until you are satisfied with the pacing.
Export your video
Choose your output format and codec, then click Export. The speed changes are baked into the output. The fast parts are actually shorter and the slow parts are longer in the final file.
Tips
- Audio is preserved at normal speed (1x) and dropped for speed-adjusted segments. If you slow down a clip to 0.5x, that segment will be silent. Plan your edits accordingly.
- At 2x speed, a 60-second segment becomes 30 seconds in the output. At 0.5x, it becomes 120 seconds. Your total export duration changes based on speed regions.
- Slow motion works best on footage shot at high frame rates (60 fps or higher). Slowing 30 fps footage to 0.25x gives you only 7.5 effective fps, which looks choppy.
- Combine speed regions with trim to create dynamic edits: trim to the interesting part, slow down the highlight, speed up the rest. All in one export.
- For timelapse effects, use 4x on long footage. A 4-minute clip at 4x becomes a 1-minute timelapse with smooth motion.