DeadPixelTest.pro

Bad Pixel Test

Free online test for bad pixels — dead, stuck, and hot pixel defects on any screen. Click Full Screen and cycle through solid colors. No download needed.

Press F11 for best results on desktop

What Is a Bad Pixel?

“Bad pixel” is the everyday term — used widely in the UK, Australia, and parts of Europe — for any pixel on your screen that is not working correctly. It is an umbrella term that covers three distinct failure types:

TypeWhat it looks likeBest detected on
Dead pixelBlack dot — never lights upWhite background
Stuck pixelColored dot — red, green, or blueBlack background (all stuck pixels glow)
Hot pixelWhite dot — all sub-pixels onBlack background (brightest contrast)

The full-color cycling test above catches all three types. Stuck pixels and hot pixels can sometimes be fixed with rapid color cycling — dead pixels cannot. If you find a bad pixel that glows a color on black, try the fix tool before raising a warranty claim.

How to Run a Bad Pixel Test

Press Full Screen above or F11 on a desktop. In full screen, the entire panel — including edges — is tested. Use the color buttons to switch backgrounds manually, or press Auto Cycle to rotate every three seconds. Work through all seven colors methodically.

Start with white to find dead pixels (black dots are obvious). Then switch to black to find hot and stuck pixels (they glow against the dark). Work through red, green, and blue to catch sub-pixel faults that the white and black tests might miss.

Bad Pixel FAQ

What is a bad pixel?+
"Bad pixel" is an informal umbrella term covering any pixel that is not functioning correctly. It includes dead pixels (always black), stuck pixels (fixed on one color), hot pixels (always white — all sub-pixels on), and sub-pixel defects (one of the three R/G/B channels failed). In everyday speech, "bad pixel", "dead pixel", and "stuck pixel" are often used interchangeably.
Is "bad pixel" the same as "dead pixel"?+
"Dead pixel" is the technically specific term for a pixel where the transistor has permanently failed off — the pixel is always black. "Bad pixel" is a broader colloquial term that includes dead pixels and all other pixel defect types. In practice, most people who search "bad pixel test" are looking for the same tool — solid color cycling to find any defective pixel.
Can bad pixels be fixed?+
It depends on the type. Stuck pixels (which show a color rather than being black) can often be fixed with rapid color cycling using our fix tool. Dead pixels (permanently black) and hot pixels have lower fix rates. Run the fix tool for 10–20 minutes — if the pixel changes or disappears, it was stuck, not dead.
Are bad pixels covered by warranty?+
Yes. Whether called dead pixels, stuck pixels, or bad pixels, pixel defects fall under standard manufacturer warranties. Most brands follow the ISO 13406-2 standard, which allows a small number of defects before requiring a replacement. Dell, LG (on OLED), and some premium panel guarantees are more generous. See our warranty guide for brand-specific thresholds.
Why does my screen have bad pixels?+
Pixel defects occur during manufacturing — individual transistors in the LCD or OLED panel fail. The probability of a defect increases with total pixel count, which is why larger and higher-resolution screens have a slightly higher statistical chance of a defect. Some defects appear immediately; others develop over time as the panel ages.

Found a stuck or hot pixel?

Run rapid color cycling — it fixes many stuck pixels without a warranty claim.

Fix Bad PixelWarranty Guide