Dead Pixel Tester

Identify stuck or dead pixels on your monitor, laptop, or smartphone. Clean your screen gently before starting for the best results.

Tap screen or press arrow keys to switch colors • Press ESC to exit

How to Use

  1. 1Clean Your Screen: Dust can look like a dead pixel. Use a microfiber cloth to wipe your monitor first.
  2. 2Enter Test Mode: Click the button above to go fullscreen. This hides browser UI for a clear view.
  3. 3Cycle Colors: Click, tap, or use Arrow Keys to cycle through Red, Green, Blue, White, and Black.
  4. 4Scan Carefully: Look for any tiny dots that don't change color. A black dot on white is a "Dead Pixel". A colored dot on black is a "Stuck Pixel".

Dead vs. Stuck Pixels

Dead Pixel (Black Dot)

The transistor is dead and blocks no light. It appears as a black spot on a white background. These are usually permanent.

Stuck Pixel (Red/Green/Blue)

The transistor is stuck "on". It appears as a bright colored dot on a black background. These can sometimes be fixed!

Tip: Gently applying pressure with a damp cloth or using "pixel flasher" videos can sometimes unstuck a stuck pixel.

Screen Defect Knowledge Base

How many dead pixels are acceptable?

Manufacturer policies vary (ISO 13406-2 standard). Class I monitors allow 0 defects. Class II (most consumer monitors) allow up to 2 dead pixels or 5 stuck sub-pixels per million pixels.
Check your warranty: If you find defects within the return window, most retailers will exchange it regardless of the "acceptable" count.

Can a dead pixel spread?

Generally, no. A dead pixel is an isolated hardware failure of a single liquid crystal cell or transistor. It does not "infect" neighboring pixels like a virus. However, if the screen was physically damaged (impact), more pixels might fail over time in that specific area due to the underlying stress.

Does this work on OLED screens?

Yes. On OLED screens, a "black" pixel means the pixel is completely turned off. This makes it very easy to spot "stuck" pixels (which will stay lit) or "dead" pixels (which won't light up on a white background). OLEDs are also prone to "burn-in," which is a different issue where a ghost image persists permanently.