Purpose
Flat primary fields make a single dot easier to see than a normal image. The useful part is the comparison: a mark that is dark on every bright colour is a different observation from a mark that only shows on one colour, or a mark that wipes away.
Preparation
- Use a dry microfibre cloth if the glass is dusty. Do not press, poke or scrape the panel.
- Start at your normal distance, then move closer if you want to.
- If night mode, a blue-light filter or a high-contrast setting is on, leave it if that is how you use the screen and write it down.
- Ordinary room light is enough. Save a dark room for the black-field edge check.
What to look for
| What you see | Could be |
|---|---|
| Soft speck, gone after a gentle dry wipe | Dust or a mark on the surface |
| Sharp dark dot on white and on every colour, same place | A dead pixel, or debris that did not move |
| Bright dot on black | A stuck subpixel, a hot pixel, or a reflection |
| Odd dot on only one primary | A subpixel that does not match the others. Compare the rest before you name it |
Common false positives
Dust, a fibre under a screen protector, window reflections, and a camera photo that has sharpened noise. Browser zoom does not tell you which panel pixel you are on, because the operating system may be scaling.
How to interpret what you see
Write the colours where the mark shows, and whether cleaning moved it. Use words like “could be”. Manufacturers publish their own pixel policies. White Screen Checker does not set a number of acceptable defects, and it will not give you a pass certificate.
Limitations
There is no automatic detection. Optional cyan, magenta and yellow are extra views, not a second verdict. The slow 5-second cycle is only a hands-free advance. It is not a flashing fix.
Questions
Will the page circle a dead pixel?
No. You scan the field. If you see a mark, note which colours show it and whether a dry wipe moves it.
What is the difference between dead and stuck?
A dead pixel often stays dark on bright fields. A stuck subpixel can stay lit and show up on black. Dust can mimic both. These are possibilities, not a verdict.
Should I press the spot?
No. Pressure can damage a display. Clean only with a dry microfibre cloth, gently, and only if the manufacturer allows it.
How many bad pixels are acceptable?
That is the manufacturer’s policy, not this site’s. White Screen Checker does not publish a pass threshold.