Free tool
Free video speed changer, from 0.25x to 10x
Change how fast a video plays, anywhere from a quarter speed to ten times as fast.
Your video
Drag a file here, paste it, or choose one.
.mp4, .mov, .webm, .mkv. Up to 500 MB.
Up to 10 minutes long.
Your video never leaves your browser. The re-time runs on this machine.
More options
From 0.25x to 10x in steps of a quarter.
Result
Worked example
Measured on our own 27 second launch film at 1920 by 1080, at 2x.
Before
0:27, 7.6 MB
After, 2x
0:13, 2.4 MB
Half the running time means roughly half the frames to store, so the file shrinks with it. The narration still sounds like a person talking faster, because the tempo changes and the pitch does not.
1. Add a video. 2. Pick a speed. 3. Re-time both tracks. 4. Download it.
What Interlace does
Paced right the first time.
- Pick the length and the pacing before the video is made
- Narration and scene timing match
- No speeding up a recording to fit a slot
Real Interlace output, unedited. Shown silent and sped up.
Your file
walkthrough.mp4
Sped up to 1.5x
Questions
Asked and answered
No. The file is read by the page, handed to ffmpeg compiled to WebAssembly, and written back out, all on your own machine. There is no upload step, and closing the tab discards everything.
No. The audio is re-timed with a tempo filter that keeps the pitch where it was, so a voice sped up to 1.5x sounds like someone talking faster, not like a cartoon. The filter handles 0.5x to 2x in one step, so faster and slower speeds chain several of them. Above about 4x speech stops being followable, so tick Drop the audio for a silent video instead.
Yes. Pick 10x, or set any speed from 0.25x to 10x under More options. A 10 minute recording becomes a one minute timelapse. The frame rate stays where it was, so at 10x nine frames in ten are skipped, which is what makes it look like a timelapse.
The frame rate stays the same and frames are dropped or repeated to fit the new duration. Slowing footage down does not invent new frames, so 0.5x on a 30 frames a second clip looks like 15 real frames a second stretched out, and 0.25x like 7 or 8.
The original duration divided by the speed you pick. We show you the number before you start, so a 27 second clip at 2x reads as about 14 seconds. The input is still capped at 10 minutes and 500 MB, so 0.25x can turn it into a 40 minute file.
500 MB and 10 minutes. Everything runs inside one browser tab, and a tab has a fixed memory budget. Past those limits the run gets slow or fails outright, so a desktop encoder is the better tool.
Turn this into a video
Create an account and start from a document, script, or prompt.