Dead Pixel Test
A dead pixel test displays solid colour screens across your entire monitor to reveal defective pixels that do not respond normally. A dead pixel appears as a permanently black dot; a stuck pixel appears as a fixed colour dot that never changes. The average LCD panel contains millions of pixels, and even a single defective subpixel may qualify for a warranty replacement under ISO 13406-2 standards.
Ready to scan your monitor
The test displays 6 solid colours in full-screen — Black, White, Red, Green, Blue, and Gray. Scan the entire screen for any pixel that doesn't match.
Click or → next colour · ← previous · Esc exit
How Many Dead Pixels Qualify for a Warranty?
Most manufacturers follow the ISO 13406-2 standard for LCD pixel defects. The table below shows typical replacement policies — check your specific model's documentation before filing a claim.
| Brand | Dead Pixels Allowed |
|---|---|
| ASUS ROG / ProArt | 0 (zero-defect) |
| LG UltraGear | 0–1 |
| Samsung Odyssey | 1–2 |
| Dell UltraSharp | 0 (zero-defect) |
| BenQ | 0–3 |
| Generic / Budget | 3–5+ |
Source: Manufacturer warranty documentation and ISO 13406-2 LCD pixel defect standard. Policies may change — verify with your retailer before purchasing.
Types of Dead Pixels Explained
Not all pixel defects look the same. Understanding the type helps you determine whether a software repair tool is worth trying — and whether your defect qualifies under your manufacturer's warranty policy.
| Type | Appearance |
|---|---|
| ●Dead Pixel | Always black — never lights up |
| ●Stuck Pixel | Fixed colour dot (red, green, or blue) |
| ●Hot Pixel | Always white — all sub-pixels fully lit |
Dead pixels (always-black) result from permanent transistor failure and cannot be fixed by any software tool. Stuck pixels (fixed colour) still receive power and sometimes respond to pixel-cycling software that rapidly flashes colours to help unstick the liquid crystals — success rates are roughly 40–60% for recently stuck pixels. Hot pixels (always-white) are the rarest type, representing all three sub-pixels simultaneously stuck in the on position. For a deeper look at how to tell the difference, see our dead pixel vs stuck pixel guide.
What Causes Dead Pixels on a Monitor?
The most common cause is transistor failure. Each LCD pixel is controlled by a thin-film transistor (TFT) that regulates the liquid crystal layer. When this transistor loses power permanently, the pixel goes dark and cannot display any colour regardless of what image is shown — this is the defining characteristic of a true dead pixel.
Manufacturing defects account for most dead pixels found in new monitors. LCD panels contain millions of sub-pixels, and minor production flaws — including microscopic contamination, subpixel misalignment, or gate driver errors — can result in a small number of non-functioning pixels leaving the factory. This is why ISO 13406-2 defines an acceptable threshold rather than requiring zero defects on every consumer panel.
Physical damage is a third cause: impacts, drops, or sustained pressure on the panel surface can sever pixel connections or damage the liquid crystal layer. Even minor pressure during shipping can create pixel defects that only appear hours or days after purchase — another reason to test any new display within the return window. If you notice slow response alongside dead pixels, our monitor response test can check for related panel issues.
When Should You Run a Dead Pixel Test?
Unboxing a New Monitor
Test within the first 14–30 days. Most retailers and manufacturers require dead pixel warranty claims to be filed within the initial return window. Running the test immediately after unboxing gives you the best chance of a no-questions-asked replacement.
Buying a Used Display
Always test a second-hand monitor before completing the purchase. Cycle through all five colours to find defects the seller may not have disclosed — or not noticed. A single stuck pixel in the screen centre can be a significant daily distraction.
After Physical Impact
If your monitor, laptop, or phone was dropped or bumped, run a full pixel test immediately. Dead pixels from physical impact can appear hours after the incident as liquid crystals settle. Check all five colours to catch any sub-pixel damage.
Gaming and Professional Use
Competitive gamers and creative professionals notice pixel defects immediately. Even one dead pixel in a crosshair zone or colour-grading canvas is disruptive. Testing every few months keeps you aware of any new defects before they worsen.
Frequently Asked Questions
What is a dead pixel?
A dead pixel is a display pixel that no longer produces light — it appears as a permanently dark or black dot on your screen regardless of what colour is displayed behind it. Dead pixels are caused by a transistor failure in the LCD panel and generally cannot be repaired.
What is the difference between a dead pixel and a stuck pixel?
A dead pixel is permanently off (always black). A stuck pixel is permanently on — it stays lit in one colour (red, green, blue, or white) even when it should be dark. Stuck pixels are far more common and can sometimes be fixed using pixel-refreshing software or gentle pressure techniques.
Can dead pixels be fixed?
True dead pixels (transistor failure) generally cannot be fixed. However, what appears to be a dead pixel is often actually a stuck pixel, which can sometimes be resolved. Pixel-refreshing tools rapidly cycle colours to encourage the pixel to respond. Physical pressure methods carry a risk of further screen damage and are not recommended.
How many dead pixels is acceptable for a warranty claim?
This depends on the manufacturer and the ISO 13406-2 pixel defect class. Most consumer monitors fall under Class II, which permits up to 2 fully dark pixels (Type 2 defects) and 5 fully lit pixels (Type 1 defects) out of one million pixels before a warranty replacement is required. Premium and professional displays often use Class I (zero defects).
Does this test work on all screens?
Yes. The test runs in your browser and works on any screen: desktop monitors, laptop displays, tablets, and smartphones. For the best results, enter full-screen mode so the entire panel is covered by each solid colour. On mobile, your browser may not support full-screen — pinch to zoom out or use a desktop browser.
Which colour is best for finding dead pixels?
Use the Black screen to find stuck bright pixels (they will glow against the black background). Use the White screen to find dead (dark) pixels. Red, Green, and Blue screens reveal individual subpixel failures that are invisible on the all-white screen. Gray is useful for spotting smearing, ghosting, or uneven backlight bleeding.
Will dead pixels spread over time?
True dead pixels (transistor failure) generally do not spread — they are isolated hardware failures confined to a single pixel. However, physical damage that caused a dead pixel can sometimes affect neighbouring pixels if the panel structure is compromised. Stuck pixels caused by trapped liquid crystals occasionally resolve on their own. Monitor the affected area over a few days: if you notice new defects appearing nearby, the panel may be deteriorating and a warranty claim is advisable.
What is a hot pixel?
A hot pixel is a type of stuck pixel where all three subpixels — red, green, and blue — are simultaneously locked in the fully-on position, producing a fixed bright white dot on the screen. Hot pixels are most noticeable on dark backgrounds and are most easily spotted using the black screen test. Like other stuck pixels, hot pixels occasionally resolve on their own within the first few days of use and may respond to pixel-cycling software, though success rates are moderate.
Last updated: