Dead Pixel Test

Cycle solid colors in fullscreen to reveal dark dead pixels, bright hot pixels and color defects that normal content can hide.

Why this test is useful

A tiny point that stays dark on bright fields can indicate a pixel or subpixel that is not illuminating as expected. Cycle through white, black and the primary colors. A real pixel anomaly usually behaves consistently at the same physical location while the background changes.

Dead pixels and stuck pixels are not the same

A dead pixel or subpixel normally fails to illuminate as expected and is easiest to confirm by checking the same physical point across several bright and primary colour fields. A fixed coloured point belongs in the stuck pixel workflow instead.

A useful screenshot check

A physical pixel defect is not written into a screenshot because the browser and graphics system still contain the intended image. If the suspicious dot is visible inside a screenshot when that file is viewed on another healthy display, investigate the source image or software rather than treating it as proof of a panel defect.

Confirm the physical location before judging it

Move a normal window, cursor or photograph underneath the suspicious spot. A panel defect stays at the same physical coordinate on the glass while the content moves behind it. Then clean the surface gently and repeat white, red, green and blue. This sequence separates a fixed panel location from dust, an image artifact or software content without pretending the browser can identify the failed electrical component.

Before you start

• Clean the screen first so dust, fingerprints and dried cleaner are not mistaken for a panel defect.
• Start at the brightness you normally use. Extreme brightness can exaggerate some panel behavior and make the result less representative of daily use.
• Inspect the whole panel in an ordered path from one corner to the other rather than staring only at the center.

A reliable way to run the test

1. Cycle through white, black and the primary colors. A real pixel anomaly usually behaves consistently at the same physical location while the background changes.
2. When you notice a suspicious point or region, remember its exact position and repeat the same location with another pattern.
3. A tiny point that stays dark on bright fields can indicate a pixel or subpixel that is not illuminating as expected.
4. A fixed bright point is easiest to see on black or very dark gray and may be a hot or stuck pixel.

How to read the result

A tiny point that stays dark on bright fields can indicate a pixel or subpixel that is not illuminating as expected. A tiny point that keeps one color while the background changes may be a stuck subpixel rather than a completely dead pixel. A fixed bright point is easiest to see on black or very dark gray and may be a hot or stuck pixel. If a mark appears in a system screenshot, the cause may be software or rendered content rather than the physical panel. If it stays fixed on the panel but not in the screenshot, hardware becomes more plausible.

What to do next

• Cycle through white, black and the primary colors. A real pixel anomaly usually behaves consistently at the same physical location while the background changes.
• If a mark appears in a system screenshot, the cause may be software or rendered content rather than the physical panel. If it stays fixed on the panel but not in the screenshot, hardware becomes more plausible.
• A browser test does not decide whether a panel is inside a manufacturer tolerance. Use the maker pixel policy or warranty terms for that decision.

What this test cannot prove