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Dead Pixel Test

Cycle through solid colors fullscreen to spot dead or stuck pixels on monitors, TVs, and mobile screens

Updated

What is the Dead Pixel Test?

A dead pixel test helps you visually inspect a display for pixels or subpixels that do not respond as expected. The tool fills the screen with solid colors so you can look for dots that stay dark, bright, or a fixed color.

It is a visual check, not an automatic detector or repair tool. It cannot confirm that a screen is defect-free.

Use the color controls to cycle through black, white, red, green, and blue, and inspect the display yourself.

How it works

This tool displays solid colors in fullscreen so you can visually inspect your display. It cannot read the physical panel or automatically detect defective pixels.

Step-by-Step Guide

1. Enter Fullscreen Mode

Click the "Enter Fullscreen" button or press F on your keyboard to switch to fullscreen mode. This ensures the test covers your entire display without distractions.

2. Cycle Through Colors

Use the "Next Color" button or press the → (right arrow) key to cycle through solid colors:

  • Black (#000000)
  • White (#FFFFFF)
  • Red (#FF0000)
  • Green (#00FF00)
  • Blue (#0000FF)

Different colors can make different defects easier to notice:

  • Black: Dead pixels appear as bright dots.
  • White: Dead pixels appear as black dots.
  • Red/Green/Blue: Stuck pixels (fixed on a color) will stand out against the solid background.

3. Inspect Your Screen

Carefully examine your display for:

  • Dead pixels: Pixels that remain black or white regardless of the background color.
  • Stuck pixels: Pixels that stay on a single color (e.g., red, green, or blue) and do not change.

Keyboard Shortcuts

Key Action
F Toggle fullscreen mode
→ (Right) Cycle to the next color
← (Left) Cycle to the previous color

Tips for Best Results

  • Test in a dark room: Improves visibility of dead or stuck pixels.
  • Use multiple colors: Some defects are only visible against specific backgrounds.
  • Test from different angles: Stuck pixels may be more noticeable from certain viewing angles.
  • Check for dust: Ensure your screen is clean to avoid mistaking dust for dead pixels.

Examples

Test a new monitor for defects

Use fullscreen mode to cycle through solid colors and identify dead or stuck pixels on a new monitor

Fullscreen mode, color cycling
 
Visual identification of dead or stuck pixels

Check a smartphone screen

Cycle through solid colors in fullscreen and visually inspect a phone display.

Mobile browser, fullscreen mode
 
Visual inspection of the screen for pixels that do not change

Verify a TV display

Connect a laptop or use a smart TV browser to test for dead pixels on large screens

TV browser, fullscreen mode
 
Visual confirmation of screen uniformity

Frequently asked questions

How do I test for dead pixels?

Open the tool, enter fullscreen mode, and cycle through the solid colors (black, white, red, green, blue). Inspect your screen for pixels that do not change color. Dead pixels will appear as black or white dots, while stuck pixels will remain fixed on a single color.

How do I test for dead pixels on a monitor?

Connect your monitor to a device with a browser, open this tool, and enter fullscreen mode. Cycle through the colors and look for pixels that do not match the background. For best results, test in a dark room and view the screen from different angles.

How do I test for dead pixels on an iPhone or Android?

Open this tool in your mobile browser (Safari for iPhone, Chrome for Android), enter fullscreen mode, and cycle through the colors. Zoom in if necessary to inspect the screen closely. Dead or stuck pixels will appear as dots that do not change with the background.

What is the difference between a dead pixel and a stuck pixel?

A dead pixel is permanently off (black) or stuck on white and does not respond to input. A stuck pixel is frozen on a single color (red, green, blue, etc.) due to a sub-pixel malfunction. Both are defects, but stuck pixels are sometimes fixable with tools like JScreenFix.

Can this tool fix dead or stuck pixels?

No. This tool only displays solid colors for visual inspection; it cannot detect or repair pixels automatically. If you notice a possible defect, check the device manufacturer's guidance or warranty terms.

Does this tool work on all devices?

Yes, the tool works on any device with a modern browser, including desktops, laptops, tablets, and smartphones. For best results, use a browser that supports fullscreen mode (Chrome, Firefox, Safari, Edge).

Can I test multiple monitors at once?

No, the tool tests the primary display in fullscreen mode. To test a secondary monitor, move the browser window to that screen before entering fullscreen. For multi-monitor setups, test each screen individually.

What should I do if I find dead pixels?

If you notice a possible defect, document what you see and contact the manufacturer or a qualified repair provider for advice, especially if the device is under warranty.

Is this tool safe for my screen?

Yes, this tool is completely safe. It only displays solid colors and does not emit harmful signals or modify your hardware. However, prolonged use of bright colors (e.g., white) may cause temporary image retention on OLED screens.

Can I use this tool for OLED screens?

Yes, but be aware that OLED screens are more susceptible to burn-in. Avoid leaving static colors (e.g., white or red) on the screen for extended periods. Use the tool briefly to check for defects, then switch to varied content.

Why do I see no dead pixels at first, but they appear later?

Some pixels may take time to reveal defects, especially stuck pixels. Cycle through colors multiple times and inspect the screen for at least 5–10 minutes to catch intermittent issues.

Does this tool work offline?

Yes! Once loaded, the tool runs entirely in your browser with no internet connection required. Bookmark the page to use it offline anytime.

How do I exit fullscreen mode?

Press the Esc key on your keyboard or click the "Exit Fullscreen" button in the tool. On mobile, tap the fullscreen exit icon in your browser’s UI.

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