Compare a point across colours
Open the Dead Pixel Test. On white, a non-emitting pixel can appear dark. On black, a persistently lit subpixel may stand out. Red, green and blue backgrounds help reveal whether the point changes. This is a visual inspection, not an automated diagnosis.
Rule out dust and image content
Clean the display using the manufacturer’s guidance. Move or replace the content behind the mark. Dust sits on the panel surface, while a mark drawn in an image moves with that image. Broad bright patches or retained shapes are different from a single pixel-sized point.
Do not confuse pixels with resolution
Scaling can change the size of text without changing a physical defect. The Screen Resolution Checker reports CSS dimensions; confirm the configured display mode in system settings. Inspect the physical panel rather than judging only a screenshot.
Document what you can see
Photograph the screen if you need to show a panel defect to a seller or support team. A normal screenshot records rendered content and usually will not include a physical defective pixel. Note the background colours on which the mark is visible and whether it remains at the same location.
Use manufacturer support for next steps
Avoid pressing or heating the screen. This tool does not repair pixels or promise that a stuck pixel will recover. Return and warranty rules vary by product, so check the terms for the specific model. Follow the full inspection guide if you want to repeat the check consistently.