Dead Pixel Test
During the test: → / Space - next color, ← - previous, Esc - exit
What's inside
Quick colors
Red, green, blue, black, white, gray - for checking dead, stuck subpixels and dim spots.
Checkerboard & gradient
Help spot issues at color boundaries and in shades of gray.
Fullscreen mode
Via the Fullscreen API - the test expands to the full screen instantly.
Auto-cycle
Colors change automatically every 2.5 sec - hands-free.
Keyboard controls
→ / Space - next color, ← - previous, Esc - exit.
Any device
Works on monitors, laptops, phones, and tablets
Comments
Broken, stuck and dull pixels are a common problem of monitors, laptops and smartphones, which often goes unnoticed on a colorful desktop or in everyday applications. A dead pixel always remains black regardless of the image on the screen, and a stuck pixel gets stuck on one color (usually red, green or blue), but a dim pixel glows fainter than its neighbors and is noticeable mainly on a monochrome light background.
The tool displays the screen in full-screen mode and fills it sequentially with solid colors: red, green, blue, black, white and gray, which allows you to check each subpixel individually. The checkerboard pattern helps to identify problems at the borders of cells and differences in pixel geometry, while the gradient shows transitions of shades of gray, on which dim and unevenly glowing areas are clearly visible. For a more thorough check, the automatic color switching mode is available at a preset interval, which means that you do not need to press the buttons manually, just watch the screen.
The test is suitable for checking a new monitor upon purchase, diagnosing suspicious dots on a laptop or phone screen, as well as for regular prevention if the screen is intensively used for games or work. You can switch between colors and patterns using the arrow keys or the space bar, and exit full-screen mode with the Esc key.