Dead Pixel Test
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Tool Introduction
This walks a screen through the standard diagnostic sequence for finding defective pixels: solid red, green, blue, white, and black, one at a time. Step through the colors yourself or turn on auto-cycle to let it run hands-free while you watch the whole panel. The goal is to catch a dead pixel (stuck black no matter what color is shown) or a stuck pixel (stuck on one color no matter what changes around it) before you decide whether a screen is fine or needs to go back.
How to Use the Dead Pixel Test
- Go fullscreen (or press F) so the entire display is covered
- Click "Next color" to step through red, green, blue, white, and black manually
- Or turn on auto-cycle to move through each color every 3 seconds on its own
- On every color, scan the whole screen for a dot that looks out of place
- Note whether the dot stays dark on every color (dead) or stays one color throughout (stuck)
- Move your mouse or press any key to bring the controls back if they have faded out
Use Cases: Before You Keep a Screen, or Ask for a Refund
- Check a brand new monitor, TV, laptop, or phone right out of the box
- Confirm a screen before your store's return or exchange window closes
- Check a used or refurbished screen before agreeing to a purchase
- Re-check a screen after a repair to see if the issue is actually fixed
- Document a defect with photos of the screen during each test color, for a warranty claim
More Screen Tools
Want just one color at a time instead of the full sequence? The White Screen tool holds a plain white panel, handy for spotting dust as well as dead pixels, and the Black Screen tool holds solid black, useful for checking backlight bleed and OLED black levels on its own.
FAQs
What is the difference between a dead pixel and a stuck pixel?
A dead pixel stays dark (black) no matter what color is on screen, because it is getting no power at all. A stuck pixel stays lit on one color (often red, green, or blue) across every background, because one of its sub-pixels is stuck on while the others are not. Cycling through solid colors is what tells them apart.
How do I actually run the test?
Go fullscreen, then step through solid red, green, blue, white, and black, either manually or with auto-cycle. Watch the whole screen closely on each color. A dot that stays dark on every color is dead. A dot that stays the same color while the background changes around it is stuck.
Why does the test use red, green, blue, white, and black specifically?
Red, green, and blue are the sub-pixel colors a screen is built from, so each solid color isolates problems in one channel. White lights up all sub-pixels at once, making dead spots obvious, and black turns everything off, making stuck (lit) pixels obvious against the dark background.
Can a stuck pixel fix itself?
Sometimes. A stuck pixel is a sub-pixel stuck in the on or off position rather than actual hardware damage, and it can occasionally be freed by rapid color changes or gentle, careful pressure near the spot. A dead pixel, which has no power reaching it at all, generally cannot be fixed this way.
Will manufacturers replace a screen for one dead pixel?
It depends on the brand and their stated pixel policy, which usually sets a minimum number of dead or stuck pixels (often somewhere between 3 and 8, depending on the policy and screen size) before they count it as a defect. Check your specific manufacturer or retailer's policy, since one dot is often not enough on its own.
When should I run this test?
Run it as soon as you unbox a new monitor, TV, laptop, or phone, and before your return or exchange window closes. Testing early means you can still send a defective screen back, rather than discovering a dead pixel weeks later when the return period has ended.