What does this test check?
This test cycles through solid-color screens (white, red, green, blue, and black) so you can look for pixels that do not display the correct color. Common issues include:
- Dead pixels — always black, regardless of the displayed color. These pixels are permanently off.
- Stuck pixels — always lit in one color (usually red, green, or blue) even when the screen shows a different color.
- Dead zones — areas of a touch screen that do not register touch input. Our Touch Screen Test specifically measures these.
How to perform the test
- Click Start to begin the screen test.
- The screen will cycle through different solid colors.
- Look carefully at every area of the display — edges, corners, and center.
- If you spot a pixel that does not match the background color, note its position.
- Tap Finish when done to see your results.
For the best experience, use fullscreen mode to hide browser UI elements that might distract from the edges of the display.
Why different colors?
Each color reveals different types of pixel defects. A dead pixel is easiest to spot on a white background (it appears as a black dot). A stuck red pixel is most visible on a green or blue background. By cycling through multiple colors, you maximize the chance of finding any defective pixels on your display.
Browser limitations
This test cannot detect hardware defects automatically. It is a visual-inspection tool. The browser renders solid colors and you inspect the results. The test also cannot detect:
- Sub-pixel defects too small to see at normal viewing distance
- Intermittent flickering outside the test window
- Physical screen damage (cracks, pressure marks)