Dead Pixel Test
Check your display for dead or stuck pixels with this testing tool. Tap the section below to launch the full-screen examination, then click anywhere to switch through the color patterns.
Specific Screen Defect Tests
Dead Pixels, Stuck Pixels, and Hot Pixels: How to Identify Each Type
While often used interchangeably, Dead Pixels and Stuck Pixels are different hardware defects found on LCD, LED, and OLED monitors. Understanding the difference is crucial for diagnosis and potential repair.
How to Run the Dead Pixel Test?
- Clean your screen: Use a microfiber cloth to ensure you aren't mistaking dust for pixel defects.
- Start the Tool: Click the button above to enter full-screen mode (Press F11 if your browser doesn't maximize).
- Cycle Colors: Use the Left/Right arrow keys or click to switch between backgrounds.
- Inspect Carefully:
- Use the White screen to find Dead Pixels (black spots).
- Use the Black screen to find Stuck Pixels (bright spots) or Backlight Bleeding.
- Use Red/Green/Blue screens to check specific sub-pixel health.
- If you also want to check how smoothly your display is driving frames, try our Screen Refresh Rate Test.
Dead Pixels on Phones and TVs: What They Are and How to Check for Them
The testing method is essentially the same for most displays. On a phone—whether iPhone or Android—start the test and examine the screen up close; on high-resolution devices, zooming in can make small pixel issues easier to spot. For televisions, open this page using the TV’s built-in browser. View the screen from a comfortable distance and cycle through the test colors to look for irregularities across the larger panel.
ISO 13406-2 Standards & Warranty Policy
Finding a dead pixel doesn't always guarantee a monitor replacement. Manufacturers (like Dell, LG, Samsung) follow the ISO 13406-2 (updated to ISO 9241-307) standard, which categorizes screens into classes:
- Class I: Zero defects allowed. (High-end medical or military displays).
- Class II: The most common consumer standard. It typically allows 2-5 dead or stuck pixels per million pixels before a warranty claim is valid.
Check your manufacturer's specific "Zero Bright Dot" policy for details.
Frequently Asked Questions
What is a dead pixel?
A dead pixel is a pixel on a display that no longer emits light. It typically appears as a small black dot, most noticeable against light or white backgrounds. In most cases, this occurs when all three of the pixel’s sub-pixels—red, green, and blue—fail to operate.
What is a stuck pixel?
A stuck pixel is a pixel in which one or more of its sub-pixels—red, green, or blue—remain continuously active. As a result, the pixel shows a single persistent color, such as red, green, blue, or white when all three sub-pixels stay on.
What does a dead pixel look like?
A dead pixel appears as a small black dot on the screen. Because it represents a single non-lit pixel, it is easiest to see on a solid white background, where it remains a dark, unmoving spot that never changes color.
Can dead or stuck pixels be fixed?
Dead pixels are usually the result of permanent hardware failure and cannot be repaired. Stuck pixels, on the other hand, may sometimes respond to certain fixes. Common approaches include using software that rapidly cycles colors over the affected area or applying light pressure with a soft cloth — though this must be done with great care, as improper force can cause additional damage. Even with these methods, success is not guaranteed.
What is the difference between a stuck pixel vs. a dead pixel?
A dead pixel appears black because it no longer produces light. A stuck pixel, by contrast, stays illuminated in a fixed color — such as red, green, blue, or even white — because one or more of its sub-pixels remain continuously powered.
What causes dead pixels?
Defects usually occur during the manufacturing process of the LCD/OLED panel. They can also develop over time due to physical damage, overheating, or component aging.
Does this test work on Mobile (iPhone/Android)?
Yes. screentester.org is responsive. On high-resolution mobile displays (Retina/OLED), you may need to look very closely or use a magnifying glass, as pixels are microscopic.