Dead Pixel Check

Dead Pixel Test for Monitors

Run the fullscreen check on your desktop monitor — ideally on unboxing day, while the retailer's return window is still wide open.

7 full-screen colors · click, tap, swipe or press Space to advance · Esc to exit

Free · No download · No sign-up · Runs locally in your browser

Monitor-specific tips

  • • Set the monitor to its native resolution and 100% scaling first.
  • • Press F11 if fullscreen doesn't trigger automatically.
  • • On a multi-monitor setup, drag the browser to the monitor under test before starting.
  • • Inspect from about 50 cm, then again up close for 4K panels.

The unboxing-day routine

  1. Let the monitor run for 15–30 minutes — some defects only appear warm.
  2. Run the dead pixel check above, slowly, on all seven colors.
  3. Run the backlight bleed test in a dim room at your normal brightness.
  4. Run the uniformity test — panning shots and spreadsheets live on mid-gray.
  5. Record the result in a screen test report, even if the panel is clean. A dated "all clear" is useful if something appears in week three.

Found a defect on a new monitor?

Use the retailer's return window rather than the manufacturer's pixel policy whenever you can — returns don't involve counting defects against an ISO class. Manufacturer policies vary enormously: some replace a panel for a single bright pixel on premium lines, others require three or more defects. If the dot is colored rather than black, try the stuck pixel fixer first — stuck pixels are often recoverable, and knowing which type you have changes the conversation with support.

Gaming monitor? Go further

Pixel defects are only part of a gaming panel's story. After this test, check gradient handling for banding in dark game scenes, and gray uniformity for dirty screen effect that shows in fog and sky textures.