Green Screen Test Tool

This green screen tool fills your display with pure green (#00FF00). Only the green part of each pixel is lit, so it is a quick way to find dead green subpixels and stuck pixels. Our eyes are most sensitive to green, which also makes it a good color for spotting uneven brightness. You can also use a green display as a small chroma-key background.

How to Test Your Screen with Green

1. Open the green screen and switch to full screen.
2. Scan the display from corner to corner at normal viewing distance, then up close.
3. Look for black dots (dead green subpixels) and red, blue or white dots (stuck pixels).
4. If the whole screen looks dull, dark or slightly purple when it should be bright green, read the note about missing green below.

What a Green Screen Shows

• Dead green subpixels: these appear as black dots on green but can be hard to notice on other colors.
• Stuck pixels: any dot that is not green stands out strongly.
• Brightness uniformity: because green looks brightest to the human eye, darker patches and vignetting at the edges are easy to see.
• A missing green channel: if green looks very dark everywhere and white looks pink or purple, the green signal is missing. This is usually a cable, port or color format problem. See our guide to purple or pink tint fixes.

Using a Display as a Green Screen Background

A monitor, TV or tablet showing solid green can work as a chroma-key backdrop for small objects, such as products, toys or hands in a tutorial. Video editors like CapCut, DaVinci Resolve and OBS can then replace the green with another background.

• Keep the object a short distance in front of the screen so it does not reflect green light.
• Lower the screen brightness if the green spills onto the edges of your object.
• Turn off room lights that cause glare on the display.
• For filming people, a fabric green screen works better, because a display is small and glows.

Other Uses

• Compare color on two monitors side by side to see which leans yellow or blue.
• Use a dim green light as a soft night light or ambient light.
• Check whether a projector shows even color across the whole wall.

Frequently Asked Questions

Can I use this green screen for video editing?

Yes, for small objects filmed in front of the display. Download the green image or use full-screen mode, then apply a chroma key effect in your editor.

Why does my green screen look yellow?

A warm color temperature, night light or blue light filter adds red and makes green look yellow. Turn these off and test again.

What color should I test after green?

Check red and blue to cover every subpixel, then black for bright stuck pixels.