Dead Pixel Test for Your Phone
Free full-screen test for iPhone and Android. Whether you call it a phone test, mobile pixel test, or mobile screen check, this tool works on any mobile device — no app needed.
Tap anywhere to cycle colours · Long press for previous
How to Test Your Phone for Dead Pixels
- 1.Clean your screen with a microfiber cloth — dust can look like a dead pixel.
- 2.Tap Start Full Screen Test above. Set brightness to maximum.
- 3.Tap through each colour — black, white, red, green, blue, yellow. A dead pixel stays black on all; a stuck pixel shows as an unmoving coloured dot.
Phone-Specific Testing Tips
- High PPI screens (400–500+ ppi) make a single pixel about 0.05 mm — hold your phone 20–30 cm from your face.
- Disable True Tone (iPhone) and Night Mode before testing for accurate colour reproduction.
- Test in a dimly lit room — ambient glare hides faint defects.
- Check all colours: a dead pixel is black on every background; a stuck pixel appears as a bright dot only on black.
What Does a Dead Pixel Look Like on a Phone?
A dead pixel appears as a tiny black dot that stays black on every background colour. A stuck pixel looks like a bright coloured dot (red, green, blue, or yellow) that does not change. Here's how to spot them:
White background
Dead pixel = black dot
Black background
Dead pixel invisible
Red background
Dead pixel = black dot
Green background
Dead pixel = black dot
Blue background
Dead pixel = black dot
Yellow background
Dead pixel = black dot
Quick tip
A dead pixel stays black on all colours. A stuck pixel shows as a bright dot only on black. Use the full test tool to check all colours at once.
Quick Answer — Is It Covered?
If the dead pixel appeared without physical damage, it is likely a manufacturing defect and is usually covered by your manufacturer warranty. Apple typically replaces the screen for any dead pixel. Samsung requires 3 or more on Super AMOLED screens — but phones reported quickly are often replaced with just one. See the full phone dead pixel warranty guide for carrier-by-carrier details.
Frequently Asked Questions
What does a dead pixel on a phone look like?
A dead pixel is a tiny black dot that stays black regardless of what colour the screen shows. A stuck pixel is a coloured dot that does not change — often red, green, or blue on a black background.
Can a dead pixel fix itself on a phone?
True dead pixels cannot fix themselves — the organic material or transistor has failed permanently. Stuck pixels sometimes recover on their own or after running a rapid colour-cycling tool.
Is a dead pixel covered by phone warranty?
Yes, if caused by a manufacturing defect. Physical damage (dropping, pressure) is excluded. Apple covers any dead pixel; Samsung requires 3+ for guaranteed replacement. Report the issue as soon as you notice it.
What's the difference between a dead pixel and a stuck pixel on AMOLED?
On AMOLED, a dead pixel is permanently dark because the organic emitter has burned out. A stuck pixel emits the wrong colour because it is stuck in one state — this is more common and sometimes fixable with a cycling tool.
Does dropping a phone cause dead pixels?
Yes. Impact forces can damage the thin-film transistors that control individual pixels, or break the display driver IC. Dead pixels from drops are classified as physical damage and are usually not covered by standard warranty — but AppleCare+ and Samsung Care+ may cover them.
Will a dead pixel affect my phone's trade-in value?
Yes — most carrier and manufacturer trade-in programmes treat dead pixels as screen damage, reducing your payout by 20–40%. See our trade-in guide for carrier-specific policies.