How to Check Your Screen for Dead and Stuck Pixels

Updated October 31, 2026 · 5 minute read

A single odd dot on a screen is easy to miss in everyday use, and impossible to ignore once you've spotted it. If you're buying a laptop, a monitor or a phone, it's worth checking before the return window closes. Here's how to do it properly.

The three kinds of bad pixel

A dead pixel is a dot that never lights up, so it stays black. A stuck pixel is permanently lit in one color, usually red, green or blue. A hot pixel stays white. They look similar from across the room, but they behave differently on different colors, and that difference is how you tell them apart.

How to test

Wipe the screen first with a clean, dry microfibre cloth. Dust is the number one cause of false alarms. Then open our Screen Test and go through each color in full screen: black, white, red, green and blue. Dim the room a little, set your zoom to 100 percent, and look closely at the whole panel, including the corners.

A dot that's dark on white but invisible on black is likely dead. A dot that glows red on black but disappears on red is stuck on red. A dot that is white on every color is a hot pixel.

Don't confuse it with backlight bleed

If you see pale patches along the edges of a black screen, that's backlight bleed, not a pixel fault. It's a different problem, and it's usually worse in a dark room. A small amount is common, but heavy, uneven glow is worth raising with the seller.

What to do if you find one

Check the warranty before you do anything else. Many manufacturers have a pixel policy that sets how many faulty pixels are allowed before they will replace a screen, and the number often depends on where the pixels are and which model you have. If you're still inside the return window, returning the product is the simplest answer.

Can you fix it?

Stuck pixels sometimes fade or free themselves over time. Some people try gently pressing on the spot with a soft, clean cloth while the screen shows a bright color. That carries a real risk of damage, so I wouldn't push hard. Software tools that flash colors over the area have mixed results at best. Dead pixels that never light up are normally permanent.

Buying used?

Run the test before you pay, along with the rest of the checks in our second-hand laptop checklist. A screen replacement can cost a large part of what a used laptop is worth.

Run the screen test