Screen Test: Dead Pixel and Monitor Check
Inspect your display with eight full-screen patterns.
Bright full-screen colors use more power. Changing or high-contrast patterns can be uncomfortable if you are sensitive to flashing.
A visual check, not a definitive hardware diagnosis.
How to check for dead and stuck pixels
Start with a clean screen. Dust, fingerprints and reflections can look like faulty pixels. Follow your device manufacturer's cleaning instructions, and never press hard on the panel. Choose a room without direct sunlight or strong reflections. Set the screen to a comfortable brightness rather than turning it all the way up.
Start at black, then move through white, red, green and blue. Pause on each color and scan the screen in small sections, from one corner to the other. Look for a tiny spot that stays dark on lighter patterns, or a bright or colored point that stands out against black. Primary colors can help you notice a point that behaves differently on just one channel.
Check from your normal viewing distance first, then move closer if something catches your eye. On a high-resolution display, an individual pixel may be very small. If you find a spot, compare its position on several patterns. A mark on the glass, a reflection or an image artifact can look similar, so this is a visual check rather than a certain diagnosis.
Change patterns at your own pace. There is no automatic cycling or flashing. You can stop immediately if the bright colors or checkerboard feel uncomfortable. Take breaks instead of staring at a bright screen for a long time.
Dead, stuck and hot pixels explained
A pixel is one of the tiny picture elements that make up a display. Many screens combine red, green and blue subpixels to produce the color you see, although the exact layout varies between panel technologies. A problem with one subpixel can look like a single colored point rather than an entirely dark pixel.
People usually call a point that stays dark a dead pixel. A point that stays on one color is often called a stuck pixel. A persistently bright point may be described as a hot pixel or a bright-pixel defect. These are useful descriptions of what you observe, not proof of which electrical component has failed.
Display technology matters. LCD screens control light from a backlight, while OLED pixels emit their own light. Similar-looking marks can have different causes on different screens. A browser pattern cannot inspect the electronics, identify the cause or tell you whether a point can be repaired.
Write down which backgrounds reveal the point, its approximate location and whether it changes over time. Avoid rubbing, tapping or applying pressure to it. This tool does not attempt to fix pixels, and rapid flashing is not needed for the inspection.
Checking uniformity and backlight bleed
The gray and white patterns help you compare brightness and color across the panel. Look for noticeable patches, darker areas or a tint that differs from the center. View the screen straight on, because changing your angle can change how some displays look. Try a normal brightness setting and compare any variation with ordinary content too.
On a backlit LCD, the black pattern can reveal brighter patches around the edges or corners. Inspect it in a dim room, but remember that maximum brightness in complete darkness can exaggerate effects you rarely notice in use. Some IPS panels also show a glow that changes with viewing angle. These observations alone do not reliably separate backlight bleed, glow, local dimming behavior or reflections.
OLED screens do not have an LCD-style backlight, so backlight bleed is not the right explanation for an OLED issue. The gradient can reveal visible steps or banding, and the checkerboard helps you inspect contrast and edges. Your browser, graphics settings and display processing can influence both. This is not a calibrated color measurement or a replacement for a professional assessment.
What to do if you find a problem
Confirm the mark appears with other content or another input where available. If it is on the physical display, a screenshot viewed on another device usually will not capture it. Take a photograph instead: one close view and one wider view showing the location. Camera exposure can exaggerate brightness differences, so include your viewing conditions when describing the issue.
Check the manufacturer's pixel policy for your exact model and region. Coverage can depend on the number, type and location of affected pixels; do not assume every single dot qualifies for replacement. A retailer's return window may offer a separate option for a newly purchased screen. Keep your receipt and check the applicable terms before that window closes.
Contact the retailer or manufacturer with your observations and photos. Ask which checks they recommend and whether the issue is covered. Do not open the device or try pressure-based fixes. If a mark grows, the display flickers during normal use or the panel is physically damaged, stop troubleshooting with patterns and ask for qualified service advice.