Dead Pixel Test
Cycle through solid colors full-screen to spot dead or stuck pixels on your display.
Click the screen to cycle colors. Press Escape to exit. Space or Enter to advance.
How to Use This Test
Start the Test
Click 'Start Full Screen Test' to enter full-screen mode. The display will turn solid black as the first color.
Inspect Each Color
Press Space, Enter, or click anywhere to advance through Black, White, Red, Green, and Blue. Carefully scan the entire screen for dark spots or bright colored dots.
Check All Viewing Angles
Move your head slowly across the screen at different angles. Some defects are only visible from certain perspectives, especially on IPS panels.
Exit and Report
Press Escape to exit full-screen mode. If you found dead pixels, document them with photos for warranty claims.
What Your Results Mean
No Dead Pixels Found
All five solid colors appeared uniform across the entire display. Your screen is free of dead or stuck pixels.
Dead Pixels Detected
You noticed dark spots (dead pixels) or bright colored spots (stuck pixels) that didn't change with the background color.
Minor Backlight Bleeding
Some light leakage around screen edges on dark backgrounds is normal for LCD panels and doesn't constitute a defect.
Color Banding Visible
Subtle color gradients or banding on certain screens can be normal for 8-bit panels and doesn't indicate dead pixels.
Common Problems and Fixes
I found a spot on one color but not others
Some pixels may only be visible on specific colors. Re-test focusing on that area. If the spot appears on multiple colors, it's likely a dead or stuck pixel.
Can't tell if a spot is dead or just dirt
Clean the screen with a microfiber cloth first. Dead pixels remain visible after cleaning and don't move when you tilt the screen. Dirt will shift or disappear.
Found multiple dead pixels
Multiple dead pixels, especially clustered together, may indicate a panel defect rather than isolated pixel failures. Document with photos and contact the manufacturer for warranty service.
Dead pixels appeared after a screen replacement
If new dead pixels appeared after repair, the replacement panel may be defective. Contact the repair shop — reputable shops guarantee their work and will replace defective panels.
Frequently Asked Questions
What is the difference between a dead pixel and a stuck pixel?
A dead pixel appears as a permanently black dot because all three sub-pixels (red, green, blue) have failed. A stuck pixel shows a permanently lit color (red, green, blue, or a combination) because one or more sub-pixels are stuck in the 'on' state. Stuck pixels are sometimes repairable; dead pixels typically require screen replacement.
How many pixels should I check for on my display?
Modern displays have millions of pixels (a 1080p screen has over 2 million). While it's impractical to check each one individually, cycling through solid colors helps reveal defective pixels because they stand out against uniform backgrounds.
Can dead pixels spread over time?
Dead pixels themselves don't spread, but the underlying cause (panel degradation, physical damage, or manufacturing defects) can affect adjacent pixels. If you notice multiple dead pixels appearing in the same area, it may indicate a spreading panel defect.
Will this test detect all types of display defects?
This test is effective for dead pixels, stuck pixels, and significant backlight bleeding. It may not reveal subtle defects like slight color non-uniformity, minor backlight clouding, or defects only visible at extreme viewing angles. For thorough inspection, combine this with the Screen Test.
Do OLED screens have different dead pixel behavior?
Yes. On OLED displays, each pixel produces its own light. Dead pixels appear as truly black spots with no backlight glow, unlike LCD panels where the backlight still illuminates behind a dead pixel. OLED stuck pixels may appear brighter against dark backgrounds.
How do I document dead pixels for a warranty claim?
Take clear photos of each color showing the defect, note the exact screen location, record the device serial number, and note the date of purchase. Contact the manufacturer or retailer with this documentation. Many have specific dead pixel policies for warranty replacements.
Why This Test Matters
Identifying dead pixels on a new device before the return window closes
Documenting defects for manufacturer warranty claims
Checking display quality before purchasing a used device
Verifying screen repair quality after a replacement service
Assessing whether dead pixels warrant a return or exchange
Related Diagnostic Tests
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Touch Screen Test
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Device Info
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