Dead Pixel Test — Check Your Screen for Dead or Stuck Pixels
Fill your screen with solid colours to spot dead or stuck pixels and backlight bleed, plus a pixel fixer.
Free, with no sign-up and no watermark. The file is processed in your browser and never uploaded.
Fill your screen with solid colours to spot dead pixels (always dark), stuck pixels (always one colour) and backlight bleed. A flashing mode can sometimes revive stuck pixels.
Step by step
- Start the test: Press Start dead pixel test — the screen goes full-screen black.
- Cycle colours: Click, press Space or use the arrow keys to move through black, white, red, green, blue and more.
- Look closely: Check each colour for dots that don’t match; press H to hide the label.
- Finish: Press Esc (or Exit) to leave full-screen.
Handy for
New monitors and laptops
Check within the return window.
Second-hand screens
Inspect before you buy.
Phones and tablets
Open the page on the device and tap to cycle.
TVs
Use a browser on a smart TV or cast the page.
Good to know
Clean the screen first — dust can look like a dead pixel.
Use black to find bright stuck pixels and white to find dark dead ones.
Questions
Can the flashing mode fix dead pixels?
It sometimes revives a stuck pixel after 10–20 minutes. A truly dead pixel (always black) can’t be fixed by software. Avoid flashing mode if you’re sensitive to flashing lights.
Is anything sent to a server?
No. Every calculation runs in your browser, so the numbers you type never leave your device. The page keeps working offline once it has loaded.
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