How to Check Dead Pixels on Mobile (iPhone & Android)

Checking for dead pixels on a smartphone is trickier than on a monitor. Modern "Retina" and high-DPI OLED screens pack pixels so tightly (400+ PPI) that a single dead pixel is microscopic.

Why It Matters for Phones

While one dead pixel might be invisible during normal use, it can lower the resale value of your device. Plus, if you bought a flagship phone, you paid for a perfect screen.

How to Test on Android & iPhone

You don't need a specific app that requests weird permissions. You just need a full-screen web browser.

1. Turn Brightness Up: Maximize your screen brightness. This helps spot dead pixels (black dots on white) and stuck pixels (bright dots on black).
2. Open the Test Tool: Navigate to detectdeadpixel.com/test in Safari or Chrome.
3. Tap to Fullscreen: Most mobile browsers hide the address bar when you scroll or tap. Ensure the color fills the entire notch/island area if possible.
4. Rotate Your Phone: View the screen in both portrait and landscape to check corners that might be hidden by UI elements.

OLED Specifics (iPhone Pro, Samsung Galaxy, Pixel)

Most modern high-end phones utilize OLED panels. OLEDs don't have a backlight; each pixel makes its own light.

• True Black: When testing "Black", the screen should be completely off. If you see a lit pixel, it is definitely stuck.
• Burn-in vs Dead Pixels: OLEDs suffer from "burn-in" (ghost images). If you see a faint shadow of keyboard or status bar icons on a grey background, that is burn-in, not a dead pixel.

Camera "Dead Pixels"

Sometimes users search for "dead pixel camera". This refers to the camera sensor having a dead photosite, resulting in a white or black dot appearing in every photo you take at the same spot. This is a sensor defect, not a screen defect. To test this, take a photo of a completely dark room (lens cap on) and a completely white wall, then zoom in on the resulting photo 100%.