Dead pixel test: make pixel defects visible
On solid-color test screens, defective pixels, tints and stains stand out immediately – flaws that hide behind icons and photos in everyday use.
The test
Start the test and tap the screen to cycle through test colors (white, black, red, green, blue, gray, gradient). Clean your display first – dust specks look confusingly similar to dead pixels. Scan each color systematically.
Your result for this test:
Identifying pixel defects
- Dead pixel: stays black on every color. The pixel gets no power – permanently defective.
- Stuck pixel: glows constantly in red, green or blue; easiest to spot on a black background.
- Bright patch / backlight bleed: pale clouds visible on white or gray point to pressure damage in an LCD's backlight.
- Burn-in (OLED): ghosts of the status bar or keyboard visible on the gray test screen are burned-in content – wear, not sudden failure.
- Lines and stripes: continuous colored or black lines indicate a driver or cable fault, not individual pixels.
What to do about pixel defects
A single dead pixel is annoying but technically harmless – it normally doesn't spread. Stuck pixels occasionally recover on their own or after displaying rapidly changing colors for a while; no guarantees. We advise against pressure or "massage" tricks: on modern displays you're more likely to cause damage than fix any. For stains, lines or growing defects, only a display replacement helps.
Warranty notes
Many manufacturers tolerate a small number of pixel defects in their policies before accepting a display as faulty; thresholds vary by brand and device class. For a newly bought device: document the defect with a photo (this test makes a good backdrop) and report it quickly. For buyers in the EU: during the first 12 months after purchase, the defect is legally presumed to have existed at delivery. Outside the EU, rules vary by country.
Frequently asked questions
Do dead pixels spread?
Single dead pixels usually stay stable. Growing black blotches aren't dead pixels but liquid ingress or panel damage – that gets worse and calls for a display replacement.
Can an app fix dead pixels?
Apps flashing rapid colors can sometimes revive stuck (colored) sub-pixels. Truly dead (black) pixels can't be fixed by any software.
Does this test work for monitors and tablets?
Yes. Just open this page on the device you want to check – the fullscreen test colors work on any screen with a browser.