Phone Dead Pixel Test
Full-screen colour test for iPhone and Android. Tap through each colour to find dead or stuck pixels.
Tap anywhere to cycle colours · Long press for previous
How to Use the Test on Your Phone
- 1.Set screen brightness to maximum and disable True Tone or Night Mode.
- 2.Tap Start Full Screen Test. The tool will fill your screen with a solid colour.
- 3.Tap to cycle through all six colours. Inspect each one carefully from 20–30 cm away.
- 4.Any dot that does not match the background is a defective pixel.
What to Look For — Examples on Each Colour
Black
Bright or coloured dots = stuck pixels
White
Dark dots = dead pixels
Red
Black or wrong-colour dots
Green
Black or wrong-colour dots
Blue
Black or wrong-colour dots
Yellow
Especially useful for blue sub-pixel defects
iPhone vs Android Dead Pixel Testing Differences
iPhone (OLED / Super Retina XDR): True dead pixels are uncommon — each pixel generates its own light. Disable True Tone in Settings → Display & Brightness before testing. Use the AssistiveTouch floating button (Settings → Accessibility → Touch) to isolate a suspect pixel from UI elements.
Android (AMOLED / LCD): Samsung Galaxy users can dial *#0*# to open Samsung's built-in display diagnostic tool. For all other Android phones, use this browser tool. Test on a neutral grey as well — AMOLED screens can show burn-in artefacts that are sometimes confused with dead pixels.
What to Do Next
Frequently Asked Questions
How do I use the dead pixel test on my phone?
Tap "Start Full Screen Test", then tap anywhere to cycle through black, white, red, green, blue, and yellow. Look for any dot that does not match the background colour.
What should I look for on each colour?
On black: look for bright or coloured dots (stuck pixels). On white: look for dark dots (dead pixels). On red, green, or blue: look for dots of the wrong colour.
Does the test work on iPhone?
Yes. Open this page in Safari, tap Start Full Screen Test, and use the AssistiveTouch floating button to cover any suspect spot to confirm it is on the display, not in the UI.
Does the test work on Android?
Yes, on all Android browsers. Samsung users can also dial *#0*# in the Phone app for the built-in diagnostic screen test.
What should I do after finding a dead pixel?
If the phone is new, try the fix tool first. Then check your warranty — manufacturing defects are usually covered. If you dropped the phone, your options are repair or an insurance claim.
Can I test without downloading anything?
Yes. This is a browser-based tool. No app, account, or download required.