Fill the whole screen with a solid color to check for dead pixels or blemishes.
β οΈ Photosensitivity warning: colors switch and the whole screen flashes brightly. If you have a history of photosensitive seizures, please do not use this test.
Once fullscreen, click anywhere or use the arrow keys (β/β) to cycle colors. Press Esc anytime to exit.
Current color: β
A dead pixel is a single pixel on a monitor that fails to display color correctly β it may stay permanently off (dead pixel), get stuck showing one color (stuck pixel), or show as a persistently bright dot (hot pixel). The most reliable way to spot these on a new monitor, laptop, phone, or a used device you're inspecting is to fill the whole screen with a solid color and look closely.
Click "Start fullscreen" to fill the entire screen with a solid color. Click anywhere or press the arrow keys (β/β) to cycle through white, black, red, green, blue, and gray, and look for any spot that differs from its surroundings (a dot, smudge, or streak). It helps to check in a slightly dim room, at your normal viewing distance from the screen.
White and gray screens are great for spotting dust, smudges, or backlight bleed (uneven brightness). A black screen is best for catching an always-on bright dot (hot pixel) or light bleed around the edges. Pure red, green, or blue screens help isolate which subpixel (R/G/B) has failed β for example, a dark dot that only appears on the red screen points to a broken red subpixel at that spot.
Re-check the spot from a different angle and on a different color to rule out reflections or dust rather than a real defect. On a new device, check the manufacturer or retailer's dead-pixel warranty policy (how many pixels are tolerated before a swap is offered) and take a photo as evidence. A stuck pixel (fixed color) occasionally recovers from rapid color cycling, but a true dead pixel (completely off) is a hardware defect that software cannot fix.
This tool only changes color when you click or press an arrow key β it never flashes automatically β but rapidly alternating between bright white and dark black can still cause glare or discomfort for some people. If you have a history of photosensitive seizures or migraines, please avoid this test, and press Esc immediately to exit if you feel dizzy or uncomfortable at any point.