A tiny dot that refuses to match the rest of the screen may be a dead pixel, a stuck subpixel, dust, or a surface mark. The safest way to tell is to compare the same spot across several solid colors.
Dead, stuck, and bright pixels are not the same
A display pixel is usually built from red, green, and blue subpixels. A dead pixel remains dark because the pixel or its control path is no longer producing the expected light. A stuck subpixel remains active at one value, so the point may look red, green, blue, cyan, magenta, or yellow depending on which channels are affected.
A bright pixel is most obvious on black because it stays illuminated when the surrounding pixels are dark. These labels are useful descriptions, but a browser page cannot determine the electrical cause or decide whether a manufacturer will treat the point as a warranty defect.
Use five colors to classify the spot
Clean the panel using the maker’s instructions, set browser zoom to 100%, and open the fullscreen dead pixel test. Check black, white, red, green, and blue while keeping your head near the normal viewing position.
A point that is dark on white and multiple colored screens is more consistent with a dead pixel. A point that stays colored while the background changes is more consistent with a stuck subpixel. A point visible only from certain angles or that appears to move relative to the pixel grid is more likely to be dust, glare, or a surface mark.
- Black reveals pixels or subpixels that remain bright.
- White reveals points that remain dark or strongly tinted.
- Red, green, and blue help isolate individual channel faults.
- Gray can reveal subtle bright points and nearby uniformity changes.
Verify before deciding it is a defect
Change the displayed color, viewing distance, and room lighting. Do not press, massage, or rub the panel: pressure can damage the display layers and may create a larger problem than the original point.
If the mark is part of a wider patch, tint, or vertical band, run the screen uniformity test as well. A single pixel fault and a panel-uniformity issue require different evidence when you speak with a retailer or manufacturer.
What to record for a return or warranty request
Record the pixel position, the colors on which it is visible, the monitor model, input, resolution, and picture mode. A photo can document location, but camera focus and moiré can misrepresent individual pixels, so include your written observation too.
Pixel-defect policies vary by maker, model, region, and defect count. Check the current official policy and your retailer’s return window instead of assuming that one visible point automatically qualifies for replacement.
Try the tools
Check the behavior on your display.
DisplayCheck provides visual checks and browser capability reports. Objective color, luminance, physical response time, contrast, and gamut measurements require suitable instruments.