Click for next color / Press ESC to exit

🔴 Dead Pixel Test

Displays a solid color in fullscreen to check for dead pixels (stuck-on or stuck-off pixels) on your monitor.

Click the colors below to check individually, or use the button to test all colors in sequence. While in fullscreen, click for the next color or press ESC to exit.

Select test color

赤
緑
青
白
黒
灰
1Select a color or press a button
2Check the entire screen in fullscreen
3Click to go to next color
ESCEnd test

Usage and Application Examples

  • Check for dead pixels when purchasing a new monitor
  • Quality check before buying a used monitor
  • Individually check each sub-pixel with red, green, and blue
  • Check for bright and dark spots overall with white and black

What is Dead Pixel Test?

Dead Pixel Test is a full-screen diagnostic utility that identifies dead or stuck pixels on monitor and display screens. It systematically cycles through six solid colors (typically red, green, blue, white, black, and gray) to reveal pixels that fail to respond—whether they're always-on "hot" pixels or always-off "dead" pixels. This free tool works on any device with a web browser, requiring no installation and providing immediate, actionable results for screen quality assessment and hardware troubleshooting.

How to Use

Launch the tool and it automatically fills your entire screen with the first test color, typically red. Examine your monitor closely from multiple angles and distances, looking for pixels that appear distinctly different from the surrounding color—they'll appear as tiny dots of the opposite color. The tool automatically transitions to the next color after a set interval or at your command. Proceed through all six colors, watching carefully for anomalies. Mark down any suspicious pixel locations by taking mental notes or screenshots. Repeat the test from a different distance or angle to confirm findings. Move away from the screen to view the display as a whole and catch subtle pixel issues that are harder to see up close. Pay special attention to the screen edges and corners where dead pixels commonly appear.

Use Cases

New monitor purchases require testing before the return window closes—dead pixels are usually warranty-covered at purchase but not later. Laptop screen damage assessment helps determine if repairs are economically worthwhile versus replacement. Used monitor purchases need verification before payment to ensure quality. School and office IT departments test classroom projectors and display equipment for maintenance purposes. Gaming and design professionals verify that expensive high-resolution monitors are defect-free before critical work. Warranty claim documentation benefits from identifying and photographing dead pixels—manufacturers request evidence of manufacturing defects. Display aging monitoring tracks whether pixels develop problems over years of use. Troubleshooting video cables and connections helps distinguish between display problems and signal issues.

Tips & Insights

Dust and smudges differ from dead pixels—dead pixels remain consistently visible through the color transitions while dust appears to move. Viewing distance matters; pixels invisible from normal viewing distance may be acceptable under manufacturer standards. Manufacturers typically tolerate 0–5 dead pixels depending on panel grade—major brands specify acceptable defect levels. Black color test reveals stuck-on pixels easily, while white test shows stuck-off pixels. Taking photos of suspected dead pixels under full-screen color conditions helps identify locations for warranty claims. Professional tools charge money while this free version covers the same functionality. Multiple monitors may show different pixel densities—4K monitors are harder to inspect thoroughly than 1080p due to pixel density.

Frequently Asked Questions

How do I use the dead pixel test?

Displays solid colors (red, green, blue, white, black, gray) in full screen sequentially. Carefully observe the entire screen for pixels that are always on or always off. Click to switch to the next color, press ESC to exit.

What is a dead pixel?

It's when a pixel in an LCD panel doesn't function properly. There are two types: "bright pixels" that are always on and "dark pixels" that are always off.

Can dead pixels be repaired?

Since it's fundamentally a hardware issue, software cannot repair them. Depending on the manufacturer's warranty policy, panel replacement may be covered.

Which colors are most effective for testing?

Testing with red, green, and blue to individually check each sub-pixel, then using white and black to check for overall bright and dark spots is most effective.

Can I use it with my smart phone?

Yes, it works, but it's most effective on desktop monitors. Smartphones may not support the fullscreen API.

How long should I run the dead pixel test?

Run each color for at least 10-15 seconds per section of your screen, spending extra time on areas where you suspect problems. A full comprehensive test typically takes 2-3 minutes total.

What's the difference between a stuck pixel and a dead pixel?

A stuck pixel displays only one color (usually red, green, or blue) while a dead pixel shows black and doesn't display anything. The test uses different color patterns to identify each type.

Can I test my laptop screen with this tool?

Yes, the full-screen test works on laptops, though external monitors show problems more clearly. Laptop screens are more prone to dead pixels due to manufacturing variation.

Does this tool work on OLED displays differently?

OLED displays can show dead pixels, but they appear different than LCD panels—often as black spots or color shifts. The color test pattern remains effective for OLED screens.

What if I see a pixel that looks different but I'm not sure?

Stare at the area for 20-30 seconds to confirm it's not an optical illusion or dust. Compare the suspicious pixel to surrounding ones under the same color to verify.

How often should I check my monitor for dead pixels?

Check new displays within the return window (first 1-2 weeks), then periodically if you suspect issues. Monitors can develop dead pixels over time with heavy use or heat stress.