How to Test for Dead Pixels on Any Screen

Whether you just bought a new monitor, laptop, tablet, or phone, one of the first things you should do is check for dead or stuck pixels. A single defective pixel might seem minor, but it can be incredibly distracting once you notice it, especially on a screen you use every day for work or entertainment.

What Are Dead and Stuck Pixels?

A dead pixel is a pixel that no longer receives power and stays permanently black regardless of what is displayed on screen. Dead pixels are usually caused by manufacturing defects or physical damage to the display panel. Unfortunately, dead pixels are almost always permanent.

A stuck pixel is slightly different. It remains fixed on a single color, often red, green, or blue, because one or more of its sub-pixels are stuck in an on state. The good news is that stuck pixels can sometimes be fixed by rapidly cycling colors or gently massaging the affected area with a soft cloth.

Step-by-Step Guide Using the Full Screen Color Tool

The easiest way to test for pixel defects is to display a single solid color across your entire screen and visually scan for any dots that do not match. Our Full Screen Color Tool makes this effortless. Here is how to do it:

1. Open the Full Screen Color Tool in your browser.
2. Select a solid color and enter full-screen mode by clicking the full-screen button or pressing the appropriate key.
3. Carefully scan every area of your screen for any pixel that does not match the background color. Move your eyes slowly from left to right, top to bottom.
4. Repeat the test with each of the following colors: white, black, red, green, and blue. Each color activates different sub-pixels, so testing all of them ensures complete coverage.

Tips for Each Color

White: A white screen makes dead pixels (black dots) very easy to spot. This is the best starting color for a quick check.

Black: On a black background, stuck pixels that are lit up in red, green, or blue will stand out immediately. This also helps identify backlight bleed on LCD panels.

Red, Green, Blue: Testing each primary color individually helps you identify which specific sub-pixel is stuck. For example, a bright green dot on a red screen means the green sub-pixel is stuck on.

What to Do If You Find Dead Pixels

If you discover a stuck pixel, try running a pixel-fixing video or tool that rapidly flashes colors on the affected area. This can sometimes unstick the sub-pixel by exercising it. Let it run for 20 to 30 minutes and then check again.

For dead pixels, there is unfortunately no software fix. If your display is new and under warranty, contact the manufacturer. Many brands have dead-pixel policies that allow a return or replacement if the number of defective pixels exceeds a threshold, often as few as one to three bright dead pixels.

To get started, head over to the Full Screen Color Tool and run a quick test right now. It is free, requires no downloads, and works on any device with a modern browser.