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

A dead pixel always stays black no matter what color the screen shows; a stuck pixel always lights up in one fixed color. Dead pixels usually can't be fixed, while stuck pixels can sometimes be fixed.

Do I need to install software to check a screen for dead pixels?

No. You scan 6 full-screen colors right in your browser with a free tool, with nothing to install.

Check a Laptop Screen for Dead Pixels Online (Free)

Q: How many dead pixels mean you should pass on a laptop?

1 dead pixel at the edge can be acceptable if the price is good; a dead pixel in the middle of the screen, or several, means you should return it. For a newly bought screen, ask for a replacement if there is any dead pixel at all.

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Dead pixels are the most common defect when buying a used laptop or monitor. This article shows how to check a screen for dead pixels right in your browser — free, with no software to install. It also explains how to tell dead pixels from stuck pixels and how to deal with them.

🖥️ CHECK FOR DEAD PIXELS NOW →
Free · full-screen scan of 6 colors in your browser

Table of contents 6 items

What Is a Dead Pixel?
How to Check a Screen for Dead Pixels Online
More Checks: Light Bleed, Color Cast, Lines
How Many Dead Pixels Mean You Should Pass on a Laptop?
Can Stuck Pixels Be Fixed?
Check the Whole Laptop, Not Just the Screen

What Is a Dead Pixel?

A dead pixel is a pixel that has failed completely and always stays black no matter what color the screen shows. This is different from a stuck pixel — a pixel that always lights up in one fixed color (red, green/blue, white). Dead pixels usually don’t go away on their own; stuck pixels can sometimes be fixed.

How to Check a Screen for Dead Pixels Online

The fastest and most accurate way is to scan through full-screen background colors one by one and look closely at each area:

Open the screen test tool, then click Start colour scan.
The screen will display 6 colors in turn: black, white, red, green, blue, gray.
On each color, look closely over the whole screen for anything unusual: a dark dot on a bright background = a suspected dead pixel; a bright dot of a different color on a black background = a stuck pixel.
Wipe the screen with a soft cloth first to rule out dust and dirt that could mislead you.

Checking a laptop screen for dead pixels by scanning 6 full-screen colors — **The real interface:** click “Start colour scan” to scan 6 colors that fill the screen; click the mouse or press Space to go to the next color, and Esc to exit. There are also *Gradient screen*, *Text sharpness*, and *Viewing angle* buttons to check for color casts, color shifts, and panel quality.

More Checks: Light Bleed, Color Cast, Lines

Light bleed (LED bleed): on a black background, the edges/corners are abnormally bright. Mild bleed is acceptable; severe bleed (large blotches) is annoying when watching dark movies.
Color cast: an area of the white background looks yellowish/bluish.
Vertical/horizontal lines: a sign of a faulty display cable or panel — best avoided.

How Many Dead Pixels Mean You Should Pass on a Laptop?

There is no absolute standard, but from experience: 1 dead pixel at the edge of the screen can be acceptable if the price is good; a dead pixel right in the middle of the screen, or several, means you should return the laptop. For a newly bought screen, ask for a replacement if there is any dead pixel at all.

Can Stuck Pixels Be Fixed?

Stuck pixels sometimes go away after running rapid color changes continuously for a few dozen minutes, or after gently massaging the exact spot with a soft cloth. A truly dead pixel is almost impossible to fix at home.

Check the Whole Laptop, Not Just the Screen

The screen is only one part. Before accepting a used laptop, you should test everything: keyboard, battery, speakers, hard drive, CPU… See the full guide: Check a laptop online — a 14-step used laptop test.

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