How to Test for Dead Pixels on Any Screen (Complete 2026 Guide)
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A dead pixel is one of the most frustrating display defects you can discover on a brand-new monitor or laptop screen. Whether you are buying a secondhand device or troubleshooting a current one, knowing how to perform a proper dead pixel test can save you time, money, and headaches. This complete 2026 guide walks you through everything you need to know.
What Is a Dead Pixel?
A dead pixel is a screen pixel that no longer receives power or cannot display colour. It appears as a permanently black dot on your screen regardless of what image is displayed. This is different from a stuck pixel, which is permanently lit in red, green, blue, or white. Understanding the difference matters because the fix — and warranty coverage — can vary significantly between the two.
Types of Pixel Defects
- Dead pixel – completely black, receives no power
- Stuck pixel – locked to one colour (red, green, blue, or white)
- Hot pixel – always bright white, common in older LCD panels
- Cluster defect – a group of adjacent stuck or dead pixels
You can use our free dead pixel test tool to check for all of these defect types in under two minutes.
How to Test for Dead Pixels: Step-by-Step
- Clean your screen – Use a microfibre cloth to wipe away dust and smudges. A dirty screen can mimic pixel defects.
- Open a full-screen colour test – Visit our dead pixel test page and launch the tool.
- Cycle through solid colours – The tool will display full-screen red, green, blue, white, and black backgrounds in sequence.
- Look for anomalies – On each colour, scan your screen carefully. A black dot on a coloured background indicates a dead pixel. A coloured dot on a black background indicates a stuck pixel.
- Note the location – If you find a defect, note its approximate position (top-left, centre, etc.) for warranty documentation.
- Test in a dim room – Ambient light makes defects harder to spot. Dim the room lights for the most accurate results.
How Many Dead Pixels Are Acceptable?
Monitor manufacturers follow the ISO 13406-2 standard, which classifies screens into four defect classes. Most consumer monitors fall into Class II, which permits up to 2 fully dead pixels, 2 fully lit pixels, and 5 partial sub-pixel defects per million pixels before a warranty claim is valid. A 1080p display has over 2 million pixels, so theoretically a manufacturer could allow up to 4 dead pixels before offering a replacement.
However, many premium monitor brands — including ASUS ROG, BenQ, and Dell UltraSharp — offer zero dead pixel warranties. Always check the policy before purchasing. For a deeper breakdown, see our guide on how many dead pixels are considered normal.
Can You Fix a Dead Pixel?
True dead pixels — those that receive no electrical signal — cannot be fixed with software tools. However, what many users believe to be dead pixels are actually stuck pixels, which can sometimes be revived. Pixel-flashing tools rapidly cycle colours to jolt a stuck sub-pixel back to life. The success rate is around 60% for fresh stuck pixels. Learn more in our dedicated stuck pixel fix guide.
When to Test Your Screen
- Immediately after unboxing a new monitor or laptop
- Before the return window closes (typically 14–30 days)
- After a physical impact or pressure on the screen
- When buying a used or refurbished device
Frequently Asked Questions
Can a dead pixel spread to other pixels?
Dead pixels do not spread on their own. However, if the defect is caused by underlying electrical damage or manufacturing defects in the TFT substrate, adjacent pixels may also fail over time.
How long does a dead pixel test take?
A thorough manual inspection using our tool takes about 2 to 5 minutes depending on your screen size and how carefully you scan each colour frame.
Is there a dead pixel test for phones?
Yes. Open our dead pixel test tool in your mobile browser and rotate your phone to landscape for a full-screen experience. The process is identical to a desktop test.
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