Read the result, one color at a time
Inspect the same physical point on every color. A dark point on white can come from a pixel fault or debris; a point that remains bright on black suggests a bright pixel or subpixel. Manufacturers distinguish bright and dark defects, and coverage varies by model. See Dell’s definitions and policy guidance.
Dark on white, not bright on black: record whether it is also dark on red, green or blue. Then rule out dust and confirm with the device’s built-in test.
Bright on black: record the point’s color and how it changes across RGB. Use the stuck pixel check.
Fuzzy, irregular or visible in a screenshot: use the dust comparison or software and input checks before calling it a dead pixel.
The test asks the browser for exact black, white and individual RGB channels. It cannot measure the light from your panel or guarantee that a dot is electrically dead. Read the pattern values and browser limits, or use the full observation comparison.
What to look for
- Clean the screen first; surface dust can look exactly like a tiny defect.
- Use white to find dark points, then red, green, and blue to see whether one color component of the pixel fails.
- Confirm the mark with the display’s built-in test before filing a warranty claim.
- Photograph the physical display with another camera; a screenshot cannot capture a defect in the screen itself.
Use this order
- Open the full-screen white test and inspect edge-to-edge.
- Repeat red, green, and blue manually.
- Open black to see whether the point actually glows.
- Record location and count before checking the exact retailer or manufacturer policy.
Common questions
Can software fix a dead pixel?
Not if the pixel or subpixel is truly electrically inactive. Confirm it, document it, and check return, warranty, or service options.
Should I return a new monitor for one dead pixel?
That is a personal choice and a policy question. If the retailer return window is open, inspect the whole screen and protect that option before experimenting.