Screen Tester
Screen cleaning aid and dead pixel tester.
Dead Pixel Checker & Screen Cleaning Aid
Check your monitor, laptop, or phone screen for defects with our full-screen solid color tests. Use specific colors to reveal dead pixels, stuck pixels, backlight bleeding, and screen burn-in.
How to use the Screen Tester:
- Click a Color: Select White, Black, Red, Green, or Blue from the grid.
- Full Screen Mode: The tool instantly fills your entire display with the chosen color.
- Inspect: Look for tiny black dots (dead pixels) or colored dots (stuck pixels) that shouldn't be there.
- Clean: Use the White screen to spot dirt and smudges; use the Black screen to spot dust.
- Exit: Press ESC or click the mouse to return to the menu.
Which color should I use?
- White (#FFFFFF): Best for general cleaning and checking color temperature uniformity.
- Black (#000000): Essential for checking backlight bleeding (light leaking from edges) and identifying 'stuck' lit pixels.
- Red, Green, Blue: These primary colors help isolate failed sub-pixels. If a pixel is black on a Red screen but works on others, the red sub-pixel is dead.
What is a dead pixel vs. a stuck pixel?
A dead pixel is permanently off and appears as a tiny black dot, which is most visible on a White background. A stuck pixel is permanently on and usually appears as a bright red, green, or blue dot, which is easiest to spot on a Black background. While dead pixels are often permanent hardware failures, stuck pixels can sometimes be fixed with flashing software (though this tool is strictly for diagnosis).