Dead Pixel Tester
Detect dead, stuck, or hot pixels on your monitor with full-screen color tests
Select a starting color and click Start Test
Starting with: Black
Your browser may ask for full-screen permission
About Dead Pixel Testing
What is a dead pixel?
A dead pixel is a display pixel that no longer receives power and remains permanently black, regardless of what color is displayed on screen. Dead pixels are hardware defects in the LCD or OLED panel.
What is a stuck pixel?
A stuck pixel is a pixel that is permanently lit in a single color — usually red, green, or blue — regardless of the image being displayed. Unlike dead pixels, stuck pixels may sometimes be fixed by cycling colors rapidly.
What is a hot pixel?
A hot pixel appears as a bright white dot that is always on. It differs from stuck pixels in that it emits all color channels simultaneously. Hot pixels are more visible against dark backgrounds.
Why test with solid colors?
Solid full-screen colors provide maximum contrast to reveal defective pixels. A dead pixel will appear as a black dot on white, while a stuck pixel stands out clearly against a matching or contrasting solid background.
How to Use the Dead Pixel Tester
- 1
Click "Start Full-Screen Test"
The page will expand to cover your entire screen. Allow the browser to enter full-screen mode if prompted.
- 2
Inspect the screen carefully
Scan every area of your monitor looking for dots that differ from the solid background color. Move closer if needed.
- 3
Cycle through all colors
Click anywhere or press the right/left arrow keys to advance through Black, White, Red, Green, Blue, Cyan, Magenta, Yellow, and Gray.
- 4
Press Escape to exit
Press the Esc key at any time to leave full-screen mode and return to this page.
Common Use Cases
New Monitor Inspection
Test a brand-new monitor before your return window closes. Many manufacturers allow returns for displays with more than a set number of dead pixels.
Used Display Purchase
Verify a second-hand monitor or laptop screen before buying. Checking for defective pixels is a critical step when purchasing used electronics.
Photography & Video Editing
Ensure your editing monitor is defect-free. Even a single stuck pixel can cause color-grading errors when it blends with the content you are working on.
Warranty Claims
Document defective pixels to support a warranty or manufacturer return claim. Screenshots of the affected areas alongside the test results can strengthen your case.
Gaming Monitor QA
Gamers demand perfect displays. Running a dead pixel test before settling into a new gaming setup ensures you get the best visual experience possible.
IT & Hardware Support
IT professionals can use this tool to quickly diagnose display problems for end users without installing additional software.
Frequently Asked Questions
Everything you need to know about dead pixel testing
Can dead pixels be fixed?
True dead pixels (no power reaching the pixel) generally cannot be repaired without replacing the panel. Stuck pixels, however, can sometimes be fixed by rapidly cycling colors using a pixel-exercising tool or by gently massaging the affected area.
How many dead pixels is too many?
Most manufacturers follow ISO 13406-2 standards. Class II monitors (common consumer displays) allow up to 2 type-1 (bright) defects and 5 type-2 (dark) defects per million pixels. Check your display's warranty for the specific policy.
Why does black show on a white screen?
A black dot on a white background is the classic sign of a dead pixel — one where the liquid crystal element is stuck closed, blocking the backlight completely. These are the most visible type of pixel defect.
Does this tool collect any data?
No. This tool runs entirely in your browser using CSS and JavaScript. Nothing is uploaded to any server. Your display data stays completely private.
Does it work on mobile screens?
Yes. The tool works on smartphones and tablets too. The full-screen API is supported on most modern mobile browsers. Tap the screen to cycle through colors while testing your mobile display.
Why test with multiple colors?
Different defect types are only visible on certain backgrounds. A red stuck pixel is invisible on a red screen but stands out on blue. Testing all 9 colors maximizes your chance of finding any defect type.