Black field
A black screen makes a pixel or subpixel that remains active easier to notice as a fixed bright or colored point. Reflections and backlight behavior may also be visible, but those are not single-pixel findings.
Local visual screen check
Dead Pixel Test — Check Your Screen for Dead or Stuck Pixels
The dead pixel test fills your display with controlled colors so you can spot a point that stays dark, bright, or off-color. Everything runs in your browser; it does not capture, upload, or analyze your screen.
What did you see?
Choose the closest observation for a cautious, local-only interpretation.
A deliberate scan, not a color slideshow
How to use the dead pixel test
Start with a normal viewing setup, then compare the same suspect location instead of judging one field alone.
- Prepare the visible surface. Remove reflections and obvious dust using only care guidance suitable for your display coating.
- Choose a field in Manual mode. Custom is selected initially; click the field to activate keyboard controls, then press F or use the fullscreen button.
- Scan in a repeatable path. Move left to right in narrow rows, including corners and edges, without placing your face extremely close to the panel.
- Compare the same point. Use black, white, red, green, blue, and grey before deciding whether a mark follows a pixel or the surface.
- Record uncertainty carefully. Exit fullscreen and use the observation helper; retest rather than treating its wording as a warranty decision.
Why the fields differ
What each screen color helps reveal
White field
White drives the RGB channels together. A point that remains fully dark can stand out, although dust on the outer surface may create a very similar silhouette.
Red, green, and blue
Separate RGB fields help you compare channel behavior. A stuck subpixel may keep a tint or fail to match only some combinations instead of staying black everywhere.
Grey levels
Neutral 25%, 50%, and 75% fields can expose subtle fixed points or localized tonal changes. They can also reveal area-level uniformity effects that should not be mislabeled as dead pixels.
Cyan, magenta, and yellow
CMY combinations drive two channels at once. They add comparison evidence for an uncertain colored point, but extra colors do not guarantee that every panel defect will be found.
Custom field
A validated six-digit HEX field lets you recreate a color where a mark first became noticeable. Browser color output is useful for comparison, not a calibrated color measurement.
Understand the mechanism
What a dead pixel test actually does
A browser cannot probe the thin-film transistors, emissive elements, or subpixel electronics inside a display. A dead pixel test simply replaces busy content with uniform fields. That removes visual clutter so a fixed point is easier for your eyes to compare with its neighbors.
On an LCD, a pixel is commonly formed by red, green, and blue subpixels modulating a backlight. Other panel technologies form light differently, but the practical observation is similar: change the requested field and watch whether one tiny location follows it. The result is an observation, not direct electrical evidence.
Two different observations
Dead pixel versus stuck pixel
The terms describe different behavior and should not be used interchangeably.
| Observation | Possible dead pixel | Possible stuck subpixel |
|---|---|---|
| Bright white field | May stay dark | May show a persistent tint or partial response |
| Black field | Can blend into black | May remain red, green, blue, or bright |
| RGB fields | May fail to respond across all channels | Behavior may change according to the affected channel |
| What the test proves | Neither classification is certain from a webpage alone; surface contamination and rendering effects must be ruled out. | |
Useful moments to check
New, used, and everyday display inspection
A consistent screen check is most useful when you can still compare observations with the seller or manufacturer’s current policy.
A newly delivered display
Check the monitor, laptop, phone, tablet, or TV after it reaches normal operating temperature and before discarding packaging. Do not assume a universal defect allowance or return threshold.
A used-device handoff
Run the same fields with both parties present when practical. Note existing specks, scratches, image retention, or area-level uniformity separately from possible pixel defects.
A point noticed in daily use
Recreate the background, then compare with controlled fields. On TVs, local dimming and viewing position may change larger halos; on phones, screen protectors can trap dust.
Continue the inspection
Related pixel checks and guides
Dead pixel test questions
Can a webpage automatically detect a physical dead pixel?
No. This page displays controlled colors while you inspect the panel. A normal webpage cannot read the electronic state of a physical pixel or count panel defects automatically.
Should I use fullscreen for the dead pixel test?
Fullscreen removes ordinary page chrome and makes systematic scanning easier. If the browser refuses fullscreen, the embedded field still works; also check browser toolbars and the operating system taskbar separately.
Does a black dot always mean a dead pixel?
No. Dust, a surface mark, content, browser scaling, and a non-responsive pixel can all create a tiny dark-looking point. Compare the exact location across white, RGB, and grey fields, then recheck the surface safely.
Can this test repair a stuck pixel?
No repair is promised or performed. The tool intentionally avoids rapid flashing and physical-pressure advice. It is designed for visual comparison and documentation only.