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Dead Pixel & Screen Test

Inspect your display using solid full-screen colours. Look for tiny dots that stay dark, bright or the wrong colour.

Display result & next steps

Test your device above, then review what the browser actually confirmed. A connected device is not the same as a certified working device.

Ready for testing

No result yet. Start the test above.

  • Inspect solid colours in a clean, full-screen view.
  • An always-dark dot may indicate a dead pixel; a persistent bright/coloured dot may be stuck.
  • This visual check requires your observation and cannot detect every display defect automatically.

Results are generated locally. Copying a summary is optional; no diagnostic history is uploaded to DeviceDIY.

Expertise in plain language • Browser-based checks

How do I check a screen for dead pixels?

Quick answer

Run the full-screen colour test and inspect the display against solid white, black, red, green, blue and grey backgrounds. Look for tiny spots that remain black, bright or the wrong colour as the background changes.

How to run this test

  1. Clean the screen gently so dust is not mistaken for a pixel defect.
  2. Start the full-screen test and view the display from a normal angle.
  3. Cycle through the solid colour screens, checking edges and centre carefully.
  4. Look for pixels that stay black, bright or discoloured across backgrounds.
  5. Exit the test using the on-screen control or Escape.

Understanding your result

✓ What a good result looks like

You do not notice fixed bright, dark or incorrectly coloured dots across the test backgrounds.

! If something does not work

A persistent dot may suggest a stuck or dead pixel, but dust, screen protectors, reflections and software overlays can look similar.

Troubleshooting common problems

One dot looks permanently dark

Clean the panel surface and repeat the test across different colours. Compare with an external display if possible.

Colour patch or uneven brightness

Test at a consistent brightness and inspect the panel from straight on. Some uniformity variation is normal.

Full-screen mode unavailable

Use the colour overlay within the browser window; fullscreen support depends on browser and device.

What this browser test cannot prove: A visual colour inspection cannot certify factory pixel standards, exact colour accuracy, backlight uniformity or internal display hardware condition.

Frequently asked questions

What is the difference between a dead and stuck pixel?

A dead pixel remains dark, while a stuck subpixel may show a persistent bright or coloured point. Visual appearance can vary.

Will this test fix a dead pixel?

No. The tool helps you inspect the display; it does not repair hardware.

Can I test an external monitor?

Yes. Move the browser window to that monitor before starting fullscreen where supported.

Does it work on phones?

The colour views can help inspect mobile screens, though fullscreen behaviour and browser controls vary.

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Test guidance last reviewed: 3 November 2026. DeviceDIY uses standard browser capabilities; features and permissions can differ by device and browser. How our checks work.