Our diagnostic tool uses standard full-screen color patterns and gradients to help you visually inspect your monitor or smartphone display. By cycling through pure colors like red, green, blue, and white, you can easily spot dead pixels, backlight bleeding, or color uniformity issues. Everything runs entirely in your browser, meaning no screenshots or data are sent to our servers.

A dead pixel is a defective pixel on a screen that remains permanently black because it receives no power. You can spot it by displaying a solid white screen on your device. If you see a small black dot that doesn't change color, it is likely a dead pixel. If the dot is a solid color (like bright red or green), it might be a "stuck" pixel, which can sometimes be fixed.

Yes, absolutely. Our screen test tools are fully responsive and optimized for mobile devices, including smartphones and tablets. Simply tap the "Start Full Diagnosis" button and tap the screen to advance through the test patterns. Make sure to clean your screen before testing to avoid confusing dust with dead pixels.

Yes. The diagnostic patterns are generated locally using HTML, CSS, and JavaScript. Your screen is never recorded, photographed, or uploaded. We do not require any account creation, and we do not have access to your device's display data. To learn more about how we handle website data and cookies, please read our Privacy Policy.