What is the visual difference between a dead pixel and a stuck subpixel?

A dark point across several bright fields is often called dead; a colored point that persists on specific fields is often called stuck. Appearance alone does not reveal the electrical mechanism.

How many defects are accepted?

Policies vary by manufacturer, model, region, defect type and clustering. Check the current product warranty; a technical class does not replace the contract or applicable law.

Online Dead Pixel Test

By MonitorSmith editorial team · EXVORN.TECH • Updated September 9, 2026 • Editorial process

Cycling eight solid fields helps locate points that behave differently on bright, dark and primary-color backgrounds.

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Interface and local controls remain in Portuguese.

How to use

Open the test fullscreen and wipe the screen with a clean microfiber cloth.
Cycle through the full sequence: Red, Green, Blue, Cyan, Magenta, Yellow, White, and Black.
Inspect the entire active matrix at a comfortable distance and re-verify any anomaly.

When to use

Inspecting new or refurbished monitors, laptops, tablets and smartphones.
Recording observations before an applicable return or warranty period expires.
Locating repeatable suspicious points to compare with the manufacturer policy.

Limitations

This is a visual inspection. Dust, scaling, processing and different failure mechanisms can look similar; the tool cannot determine cause or warranty eligibility.

Frequently Asked Questions

What is the visual difference between a dead pixel and a stuck subpixel?: A dark point across several bright fields is often called dead; a colored point that persists on specific fields is often called stuck. Appearance alone does not reveal the electrical mechanism.
How many defects are accepted?: Policies vary by manufacturer, model, region, defect type and clustering. Check the current product warranty; a technical class does not replace the contract or applicable law.

Technical Methodology & Display Science

Modern displays utilize thin-film transistor (TFT) active matrices. A 4K UHD display (3840x2160) houses 8.29 million pixels and over 24.88 million discrete RGB subpixel gates lithographed onto glass substrates.

Failures in transistors, interconnects, emitters or control electronics can produce dark, bright or colored points. A browser test describes the visible pattern but cannot identify the failed component.

Technical standards provide methods and classifications, while commercial coverage depends on the current manufacturer policy and local law. The color sequence helps record which fields reveal the anomaly.