Dust under glass or a stuck pixel? How to tell

A tiny spot on your screen can look like dust trapped under the glass, a stuck pixel, or dirt on the surface. The distinction matters: cleaning may remove surface dust, but pressing the panel or running a pixel fixer will not remove debris inside it.

Use solid colors and a careful surface check to narrow it down. The Display Test can show screen colors for spotting pixel defects. If you confirm a single stuck pixel, the Stuck Pixel Fixer can try flashing colors over it, but it cannot repair dust or a physically damaged pixel.

Check the spot safely

1. Open the Display Test and move through its color test. Look at the spot on white, black, red, green, and blue screens if available. Keep your eyes at a normal viewing distance at first.
2. Turn off the screen and inspect the glass under room light. Look for a speck sitting on the surface, smudges, or a mark that changes as you move your head. Do not press the spot to see if it moves.
3. Clean the screen gently with a clean, dry microfiber cloth. If the manufacturer allows a screen-safe cleaner, apply it to the cloth, not directly to the display. Turn the screen back on and check the same colors again.
4. Look closely at the spot at normal zoom. A pixel defect is usually a tiny, sharply defined point in the screen image. Dust or debris often has a less regular edge, may look slightly blurred, or may cast a faint shadow.
5. If the mark is a single, crisp pixel that stays in the same place through the color test, try the Stuck Pixel Fixer only if you are comfortable with flashing patterns. Follow its timer, and stop if the flashing bothers you.

Do not use a pin, fingernail, or cleaning tool on the spot. Pressure can damage the display and turn a small question mark into a larger defect.

What the spot may mean

The mark wipes away

It was on the outer glass, not under it. If a faint mark remains, clean once more with a suitable cloth rather than scrubbing hard. Avoid paper towels, which can scratch some screen coatings.

The spot looks irregular or shadowy

It may be dust or another particle inside the display layers. It can be more visible on a bright solid color and less visible on a dark one. The mark may look soft-edged or have a tiny halo rather than matching the clean outline of one pixel. A browser test cannot remove it, and opening a display can cause further damage or void coverage.

A precise red, green, blue, or white point stays put

This points more strongly to a pixel or subpixel problem. A pixel is made of smaller red, green, and blue parts, so a fault in one part can leave a colored dot. A point that stays dark on every color may be a dead pixel rather than a stuck one. A flashing fixer is a possible low-risk attempt for a stuck pixel, not a reliable repair.

The spot appears in a screenshot

A physical speck on the glass will not be captured in a screenshot. If the dot appears in the screenshot when you view that image on another device, investigate the image, app, or graphics output instead. If it is visible only on the original screen, the panel or its surface is more likely.

What to do next

1. Clean only the outer surface. Use a microfiber cloth and light pressure. If the dot stays visible afterward, do not keep rubbing or press around it.
2. Compare several solid colors. A screen color test helps reveal whether the point changes color, stays dark, or looks like a shadow. Check that it remains at the same physical location on the display.
3. Restart the device. A restart can rule out a temporary graphics or app glitch. If the spot remains on the startup screen and in the browser color test, it is less likely to be caused by one app.
4. Try the fixer only for a likely stuck pixel. Use the Stuck Pixel Fixer for a limited, timed attempt, not as a general treatment for every screen mark. Flashing patterns may cause discomfort for some people. Read when pixel flashing may be unsafe before using them if you are sensitive to flashing light.
5. Check your return or warranty options. Take a photo of the defect on a plain color screen and note whether it is a dot, a shadow, or a group of marks. Manufacturers have different pixel policies, so ask about the policy for your exact display before attempting repairs.

When it is likely a display fault

If the spot survives careful cleaning, appears in the same place across different colors, and remains after a restart, treat it as a panel defect or debris inside the display. A single stuck pixel may respond to a flashing attempt, but a dead pixel, internal dust, or damaged display layers generally need service or panel replacement. If the device is under warranty or within its return period, contact the seller or manufacturer before trying anything more invasive.

Flashing colors cannot pull dust out from under glass, and repeatedly running a fixer is unlikely to help if the spot is a shadow or a cluster of pixels.