Dead Pixel Checker:
Easily Test Your Monitor in the Browser
One of the most common issues with new LCD screens, PC monitors, and smartphones is "Dead
Pixels" (or defective pixels).
This tool allows you to check for display anomalies such as dead pixels (black spots) or bright
stuck pixels without installing any dedicated software or apps. It cycles through colors on the
entire screen to help you spot imperfections.
It can also be used to check for burn-in and uneven brightness on 4K monitors and OLED panels.
Full-Screen Color Test
In addition to standard White, Black, Red, Green, and Blue, you can also check with Cyan,
Magenta, and Yellow. Switching background colors makes it easier to spot pixel defects and
display unevenness visible to the naked eye.
*Display range may vary depending on
device/browser settings.
Stuck Pixel Repair
For "stuck pixels" that remain lit in a specific color, applying high-speed color switching
or RGB noise stimulation may improve the temporary control abnormality.
*This is not effective for physical failures
(dead transistors) and may not work on OLED panels.
Mobile & Tablet Ready
Works on major browsers including Windows, Mac, Chromebook, iPhone, iPad, and Android. Use
it to inspect used devices or check your screen before applying a protective film.
*Some mobile browsers may not support complete
full-screen display due to OS limitations.
How to use Repair Mode
If you have a stuck pixel (a dot that won't change color) or minor display artifacts, try the
Repair Mode.
Drag the repair window over the defective area and leave it running for 10-20 minutes.
*Results vary. Improvement is not guaranteed.
This tool contains flashing lights and high-speed patterns. Do not look directly at the flashing area for extended periods. Use in a well-lit room. If you have a history of epilepsy or photosensitive seizures, please do not use this feature.
Press the "Start Repair" button
to show the repair window here.
*You can drag the box to move it. Press Stop to finish.
Frequently Asked Questions (FAQ)
Q. Does the warranty cover dead pixels?
A. It depends on the manufacturer and the product class. Due to the manufacturing
process of LCD panels, a small number of defective pixels may be considered "within
specification" and not a defect.
Many manufacturers follow ISO standards (e.g., ISO 9241-307) which allow for a certain
number of faulty pixels. However, if the defects are in the center of the screen or if
there are bright "stuck" pixels, some manufacturers (like Dell's Premium Panel Exchange)
may offer a replacement. Check your specific warranty terms.
Q. What is the difference between a Dead Pixel and a Stuck Pixel?
A. A Dead Pixel appears as a black dot because the transistor
controlling it is dead and cannot block light (or let it through, depending on panel
type). Physical failures like this are usually permanent.
A Stuck Pixel (or Hot Pixel) is stuck on a specific color (Red, Green,
or Blue) due to a sub-pixel error. Stuck pixels can sometimes be fixed by rapidly
flashing colors to "massage" the liquid crystals or reset the transistor control.
Q. How do I check full screen on a smartphone?
A. When you tap "Start Check", the tool attempts to go full screen. However, on some mobile browsers (like Safari on iOS), the address bar may remain visible due to OS restrictions. In that case, try scrolling down to hide the bar or manually zooming in to fill the screen.