How to Check for Dead Pixels - Step-by-Step Guide

A dead pixel test takes about ten minutes and works on any monitor, laptop, phone or tablet - no app, no download. Here's how to check your screen for dead, stuck and hot pixels, tell them apart from dust, and decide whether to fix or return the display.

What you need before testing

You only need three things: a soft microfiber cloth, a dim room, and the screen running at its native resolution and a normal brightness level. That's it - the test itself runs entirely in your browser.

Step-by-step: test your screen for dead pixels

1. 1

   Clean the screen and dim the room

   Wipe the panel with a soft microfiber cloth - fingerprints, fibers and dust are the most common false positives. Then dim nearby lights so glare doesn't hide tiny defects.

2. 2

   Launch a full-screen test color

   Open a free online dead pixel test and switch to true full screen. If the browser doesn't go full screen automatically, press F11. Any browser chrome left visible can hide a bad pixel.

3. 3

   Cycle through white, black, red, green and blue

   These five solid colors cover every defect type. Move through them one at a time with the arrow keys or by clicking.

4. 4

   Scan the whole panel slowly

   Give each color 30-60 seconds. Sweep your eyes across the screen in rows, top-left to bottom-right, including the corners and edges of ultrawide monitors.

5. 5

   Confirm it isn't dust or a software artifact

   Take a screenshot and view it on another device. If the dot is gone from the screenshot, it's a real hardware pixel defect, not a GPU, driver or scaling issue.

6. 6

   Document the defect for warranty

   Photograph the dot on the matching background (white for a black dead pixel, black for a hot or stuck pixel), note the location, and include the serial number and purchase date with your claim.

How to tell a dead pixel from a stuck or hot pixel

Each defect looks different, and the right test color makes it obvious. Use this table to identify what you're seeing.

Dead pixel or dust? How to tell the difference

How to test specific devices (OLED, 4K, iPhone, Android, MacBook)

What to do if you find dead pixels (warranty & returns)

If the screen is new, test it before the retailer's return window closes - a return is almost always simpler than a manufacturer warranty claim. Most brands follow ISO 9241-307 class II, which tolerates a few sub-pixel defects, but premium zero-bright-pixel policies from Dell, ASUS, Apple and Samsung allow none. Document the defect with photos on the matching background so you can prove what you see.

If the dot is bright red, green or blue rather than black, it's likely a stuck pixel - and those can often be revived. Try our Stuck pixel fixer before you return anything. For everything else, see the full Dead Pixel Test FAQ.