Remove a green screen
Key out a solid colour background and keep the subject.
- Runs on your device — the file is never sent anywhere
- No sign-up, no watermarks, no daily quotas
- Free, with no limit on how often you use it
How it works
Chroma keying replaces everything of one colour with something else. It is how weather forecasts and video calls put a person in front of a background, and it works beautifully on well-lit footage and badly on everything else — which is worth knowing before you film.
Getting a key that works
The screen needs to be evenly lit, with no shadows and no folds, and the subject needs to stand well clear of it so the colour does not spill onto their shoulders and hair. Tolerance controls how much variation in the colour counts as background: raise it if patches of screen remain, lower it if parts of the subject start disappearing. Edge softness feathers the boundary so the cut-out does not look pasted on.
Pick the colour from your footage
Green is standard because it is furthest from skin tones, but blue is used when the subject wears green. The default is the usual broadcast green; if your screen is a different shade, set the colour to match what is actually in the frame rather than what it was sold as.
Transparent or replaced
A transparent result is saved as WebM, because MP4 cannot store an alpha channel — that is a format limitation, not a choice made here. WebM plays in browsers and imports into most editors. If you need MP4, choose a solid colour to sit behind the subject instead.
What it cannot do
It cannot remove a background that is not a single, distinct colour. Removing an ordinary room behind someone needs a trained model, which is a different and far heavier technique than keying.
Remove a green screen — questions
Why are there green patches left?
The screen is unevenly lit. Raise the tolerance, though too much will start eating into the subject.
Why is my subject partly transparent?
Tolerance is too high, or green has spilled onto them from the screen. Lower it, and stand further from the screen when filming.
Why is the transparent version a WebM?
MP4 cannot carry transparency. WebM can, and plays in browsers and most editors.
Can it remove an ordinary background?
No. Keying needs a single distinct colour. Removing a normal room needs a trained model.