Clean before testing
Turn the screen off and clean it using the maker’s recommended method. Dust and dried marks can look exactly like pixel defects. Avoid spraying liquid directly onto the display or pressing hard on the panel. After cleaning, let the surface dry, turn the screen on, and use a comfortable brightness and your usual viewing distance. A scratch or speck outside the pixel layer can change appearance with reflections and head position.
Set the display to its native resolution and browser zoom to 100%. Open the test in fullscreen if the browser permits; the in-window fallback still works, although browser borders may conceal the edge of the display. Inspect a suspected point from your ordinary position before moving closer. Extreme brightness and close-range inspection can make insignificant texture seem like a new fault.
Use five solid colors
Open the fullscreen dead pixel test. Check black for bright points, white for dark points, then red, green, and blue for subpixel faults. Sweep your gaze systematically from corner to corner rather than staring at one spot. Pause long enough to inspect each field without leaving a bright static pattern displayed for an extended period, especially on OLED.
A dark point on white and several colored fields can be consistent with a dead pixel. A point that stays red, green, or blue while the background changes may be a stuck subpixel. A bright point on black is easier to see than on white. These are visual descriptions, not an electrical diagnosis: the browser does not know which underlying component failed. Compare the same exact location across multiple patterns before attaching a label.
Verify suspicious points
Change colors and viewing distance. A mark on the surface may shift in appearance, while a panel pixel stays aligned with the pixel grid. Try a neutral gray field as another reference. If the suspicious area spreads across many pixels or resembles a band, the screen uniformity test may better describe what you see. If a point appears only in a screenshot, inspect the source image or software; if it is visible on the physical screen but absent from a screenshot, check the screen and signal path. Neither observation alone identifies a failed component.
Do not press, rub, or run aggressive flashing or so-called pixel-fixing routines. Pressure can damage display layers, and a test pattern cannot promise repair. A second browser or input can help rule out a rendering artifact, but keep notes on what changed so you can reproduce the observation.
Check the policy
Display makers use different pixel-defect policies. Record the position, color, size, pattern, display model, input, and picture settings, then consult the current warranty or retailer return terms for your purchase. A photo can show where to look, but autofocus and moiré may make an individual pixel look larger or smaller. Include a plain-language description of what you saw with your eyes.
One bright or dark point may be tolerable in ordinary use for some people and distracting for others. Compare it with your normal work or games and decide whether it warrants a return or service request within the applicable window. For a broader setup inspection, use the new-monitor checklist; for a direct interactive pattern, stay on the dedicated pixel test page. This guide explains the inspection method rather than replacing either tool.
Dead, stuck, bright, or something else?
A display pixel is typically made of red, green, and blue subpixels. “Dead” commonly describes a point that remains dark; “stuck” describes a colored subpixel that remains visibly active; “bright” describes a point that stays illuminated on a dark field. These everyday terms describe what you can see, not the electrical fault inside the panel. The same spot can look different against different backgrounds, which is why the five-color sequence matters more than a single white-screen glance.
A broad colored patch is usually not one stuck pixel. Edge glow, dirty-screen effect, image retention, and color-management errors require different checks. If the suspect is a logo-shaped outline rather than a tiny fixed point, an OLED retention check may be more relevant. If you are using LCD and the entire corner brightens on black, compare viewing angles and a gray uniformity field instead of counting defective pixels.
Make a repeatable record
Write down the location using a simple description, such as “upper right, about one finger-width from the edge,” along with the colors that reveal it. Note whether it is still there after a safe cleaning, a browser restart, and a change of input or source when available. Keep the same room lighting and brightness for each comparison. If a second person looks at the panel, ask them to describe the spot before telling them what label you expect; this reduces the chance of interpreting an ambiguous point the same way out of suggestion.
Do not rely on a screen capture as proof of a physical pixel fault. A screenshot records the software image, not the light produced by the panel. Conversely, a camera image can show optical moiré or blown-out pixels from focus and exposure. The most useful service report pairs a location photo, if possible, with a clear account of the colors and normal-use visibility.
When a second test helps
The dedicated pixel test is intentionally simple: solid colors let you compare one point at a time. If the anomaly changes when the background becomes a gradient or a neutral gray, inspect whether it belongs to a larger region. A gradient test can reveal tonal breaks but cannot determine a dead pixel’s electrical cause. The RGB channel test can show broader channel or saturation problems, but it is not a colorimeter. Choose the follow-up based on the visible shape, not on a long list of loosely related search terms.
No browser page can promise to fix a pixel or decide whether the manufacturer must replace a panel. If a newly purchased screen has a repeatable point that bothers you in regular use, act within the applicable return period and provide the observations you gathered.