Chroma key green screen in four steps
- Load the footage. Drop your green screen clip above. The first frame is keyed right away so you can see the result.
- Choose the new background. Image is selected: click Choose image and pick a photo. Prefer a plain color? Click Color instead.
- Refine the key. Use Tolerance, Softness and Remove color spill until the edges look natural on the new background.
- Export. Pick MP4 for the widest support, choose the resolution and click Export video.
How chroma keying works
Every pixel in a video has a color made of brightness and chroma, the hue and saturation part. A chroma key compares each pixel's chroma with the key color and ignores brightness. That is why it can remove both the bright and the slightly shadowed parts of a green screen while keeping a white shirt or a dark jacket.
This tool works in the YCbCr color space used by video itself. Pixels whose chroma is within the tolerance of the key color become fully transparent. Pixels a little further away fade in over the softness range, which keeps hair and motion blur from looking cut out with scissors. Anything further away is kept as it is.
Green screen vs blue screen
| Green screen | Blue screen | |
|---|---|---|
| Light needed | Less; green reflects more light | More light for the same evenness |
| Camera noise | Lowest; sensors have twice as many green pixels | Higher, especially in compressed video |
| Spill | Stronger green spill on the subject | Weaker, less visible spill |
| Use when | Default choice for most shoots | The subject wears green, or for night and water scenes |
Both work with this chroma key: click the green or blue swatch, or use the eyedropper to sample your actual screen.
Getting a natural composite
A clean key is only half of a convincing result; the subject also has to belong in the new scene.
- Match the light direction. If the subject is lit from the left, pick a background photo where the light also comes from the left.
- Match the perspective. A background shot from eye level suits a talking head; a high angle looks wrong behind a person filmed straight on.
- Remove the spill. A green rim on hair is the most common giveaway. Keep Remove color spill on.
- Soften the edge slightly. One or two points of Feather blends the subject into the background.
- Use a slightly blurred background to mimic depth of field, or use the blur video background tool if you want to keep the original room.
Chroma key or AI?
Chroma key needs a backdrop of a single color. If your video was shot in a normal room, there is nothing to key; switch the Method to AI cutout and the tool will find the person instead. The AI mode is also the fallback when a green screen is too wrinkled or shadowed to key well. The green screen remover page covers fixing difficult green screens in more detail, and the video background changer uses AI to replace backgrounds without any screen.
Output options
- MP4 (H.264) with your new image or color background: plays on every phone, computer and social network.
- WebM (VP9) with a new background: smaller files for the web.
- Transparent WebM: set Background to None to export only the keyed subject with an alpha channel.
The original audio is kept, and the export can be the original resolution of your footage. No part of the video is uploaded.