Dead pixel test online

Show pure full-screen colors and tap to switch between them — spot any dead or stuck pixel in under a minute.

How to run the test

1. Clean the screen with a soft cloth — dust looks a lot like dead pixels.
2. Turn brightness up and start the test. It opens in full screen.
3. Tap the screen (or press Space) to cycle through white, black, red, green and blue.
4. Look closely, one section of the screen at a time.

What each color reveals

• White: dead pixels (black dots) and dust under the front layer.
• Black: stuck pixels (colored or white dots) and backlight bleed.
• Red, green and blue: faulty subpixels inside a pixel.

Before buying a used or new device

Run this test in the store or before you accept the device. Defective-pixel policies vary by manufacturer, model and region, and may depend on the number, position and type of the defect — so catching it early saves a lot of hassle. You can also save the result as an image from the "Screen info" card.

Found one — now what?

If it's colored, it's most likely stuck: try the stuck pixel fixer. If it's always black, it's dead, and the fix is usually warranty or repair.

Frequently asked questions

How many dead pixels are acceptable?

It depends on the manufacturer and the product. Many brands publish a pixel policy that allows a few defects before a replacement, and some guarantee zero bright pixels. Check the policy for your exact model and region, and note where the defect is: one in the center usually matters more than one at the edge.

Can a dead pixel spread?

A single dead pixel usually stays the same. If you see new dead pixels appearing over days, or a growing line or patch, that points to a panel or connector fault rather than a single pixel, and it's worth contacting the seller or a repair shop.

Is it a dead pixel or dust?

Dust and fingerprints move or blur when you wipe the screen and often look slightly out of focus. A pixel defect is perfectly sharp and stays in exactly the same spot on every color.

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