How to Test Your Monitor for Dead Pixels (Complete Guide 2026)
Published February 25, 2026
A dead pixel is one of the most frustrating monitor defects. You might not notice it for weeks, then one day it catches the light and you cannot unsee it. This guide explains exactly what dead pixels are, how to find them, and what you can do about them.
What is a dead pixel?
A pixel is the smallest unit of your screen — a tiny square that emits light in red, green, and blue to create every color you see. A dead pixel is one that stops working entirely: it receives no power and stays permanently black, regardless of what the rest of the screen displays.
Dead pixels are most visible on bright, white, or light-colored backgrounds. On a white screen, a dead pixel appears as a tiny black dot. They are generally considered a hardware defect and are not fixable through software.
Dead pixel vs. stuck pixel vs. hot pixel
These three terms are often confused, but they describe different problems:
Dead pixel — The pixel receives no power. It appears black on every background. Not fixable in most cases.
Stuck pixel — The pixel is powered but locked in one color: red, green, or blue. Unlike dead pixels, stuck pixels can sometimes be fixed using pixel-cycling tools that rapidly alternate the pixel through all colors.
Hot pixel — The pixel is always on, appearing as a bright white or colored dot on a black background. More common on older LCD panels and after heat damage.
How to test for dead pixels
The most reliable method is a solid-color fullscreen test. Here’s the process:
Step 1: Use a fullscreen white screen
Open a white screen tool. Look carefully across the entire display. Any dead pixel will appear as a tiny black dot against the white background.
Step 2: Check a black screen
Visit the black screen tool. Hot pixels and always-on stuck pixels will show up against the dark background.
Step 3: Run the full dead pixel test
The most thorough check is our dead pixel test, which cycles through six solid colors — black, white, red, green, blue, and yellow. Each color reveals a different type of defect:
- Black background: reveals hot pixels (always-on)
- White background: reveals dead pixels (always-off)
- Red/Green/Blue backgrounds: reveal stuck subpixels in the opposite channels
Step 4: Test in a dim room
Ambient light competes with your monitor’s output. Testing in a darkened room makes subtle defects much easier to see, especially hot pixels.
How many dead pixels is acceptable?
The ISO 13406-2 standard classifies monitors into four classes by pixel defect tolerance:
| Class | Max bright defects | Max dark defects |
|---|---|---|
| I | 0 | 0 |
| II | 2 | 2 |
| III | 5 | 15 |
| IV | 50 | 150 |
Most consumer monitors fall under Class II — which means up to 2 fully dead pixels and 2 hot pixels are within specification and may not qualify for a warranty replacement.
However, many monitor manufacturers have more generous policies. Dell, LG, ASUS, and others offer “zero dead pixel” guarantees on premium panels. Check your warranty documentation before accepting a defective panel.
Can dead pixels be fixed?
Dead pixels (truly no power) are permanent hardware failures. No software can revive them.
Stuck pixels are more promising. Because a stuck pixel is still powered, it may respond to a pixel-cycling program that rapidly alternates the pixel through all colors at high speed. This technique works in some cases — particularly for pixels that have been stuck for a short time. There is no guarantee, and it does not work on dead pixels.
A gentle physical approach — lightly pressing the stuck pixel with a soft cloth while the screen cycles — works for some people. Apply very gentle pressure, never more than a light touch, and do not press directly on the pixel with a fingernail.
Testing on phones and tablets
OLED screens (used in most modern smartphones) are particularly prone to stuck and hot pixels because each pixel emits its own light. The test works identically on mobile — tap Start Test and the fullscreen overlay will cover the entire display.
OLED panels can also develop screen burn-in after prolonged use at maximum brightness. If you see a faint ghost of a previous image on a black background, that is burn-in, not a dead pixel.
When to contact support
If you find dead pixels within your monitor’s warranty period:
- Document the defect with a close-up photo of the dead pixel.
- Check your manufacturer’s dead pixel policy (usually in the warranty documentation).
- Contact support with the photo, the panel’s serial number, and the purchase date.
Most manufacturers will replace the panel if the number of defects exceeds their policy threshold. If you purchased from a retailer, you may have additional consumer rights under local consumer protection law.
Try the test now
Ready to check your screen? Start with the dead pixel test — it takes about 60 seconds and covers all the major defect types in one pass.