How to test for dead and stuck pixels
A solid-color sequence can make a small fixed dot easier to notice. The useful observation is whether it stays at the same panel location across backgrounds; the browser cannot inspect physical pixels or confirm a defect for you.
Dead pixel versus stuck pixel
A dark, nonresponsive pixel or subpixel can appear as a dark dot on a light background. A bright or stuck subpixel can remain lit or fixed in red, green, or blue and stand out on black. Everyday labels are not a complete diagnosis: compare several colors, since a dot can blend into a matching background.
| Observation | Useful comparison | Interpretation limit |
|---|---|---|
| Dark dot on white | White and the RGB sequence | Could be a dark pixel/subpixel or a surface mark |
| Bright dot on black | Black, then RGB | Could be a bright/stuck subpixel; color alone is not confirmation |
| Broad patch or outline | Gray and ordinary content | A uniformity or retained-image observation, rather than one isolated dot |
Run a brief visual check
Use comfortable, normal brightness. Remove obvious surface marks only as your display's cleaning instructions allow; do not press or rub a suspect pixel to try to fix it.
- Open Dead Pixel Test and start the fullscreen color sequence.
- Hide controls for an unobstructed view, then compare black, white, red, green, and blue manually.
- Scan at your normal viewing distance and look more closely at a suspicious spot if needed.
- Restore controls with Tab or H, then Exit or Escape when finished.
Rule out the image and describe the spot
Move a window or change the displayed content. A spot fixed to one part of the image is a different clue from a spot fixed to the physical screen. Dust, reflections, scaling, and display processing can confuse a visual check. A screenshot records the rendered image, so it does not capture a physical panel defect; a photograph can document a visible spot, but focus and exposure affect its appearance.
What to do with a persistent observation
Record the panel location, which backgrounds reveal it, and whether it is noticeable in ordinary use. Consult the manufacturer's policy for your exact model and region; there is no universal browser-generated pass/fail pixel allowance. This test does not repair dots or promise that flashing a pattern will restore them.