Dead Pixel Test: Find Dead and Stuck Pixels
Fill your screen with solid colors to find dead, stuck and hot pixels on a new monitor, laptop, TV or phone. Runs in your browser; nothing is uploaded.
Runs in your browser. Your results never leave this device. No upload, no sign-up.
In full screen, click or press → or Space for the next color, right-click or press ← to go back, and press Esc to stop. On a touch screen, tap or swipe.
Or start from a color
Your report
Run the test above. Your results will appear here as plain text you can paste into a support chat, a return request or a forum post.
How to check your screen for dead pixels
- Wipe the screen with a dry microfiber cloth, so dust isn't mistaken for a faulty pixel.
- Press Start the full-screen test. The page fills your screen with white and hides everything else.
- Step through the colors with a click, a tap or →. On each one, scan the whole screen from about an arm's length, then lean in on anything that looks wrong.
- Look hardest at white and black: dark dots show on white, lit dots on black. The red, green and blue screens tell you which subpixel is at fault.
- Press Esc to finish, then record what you found. Copy the report if you need to show it to the seller.
Dead, stuck and hot pixels
Each pixel on an LCD or OLED screen is made of three subpixels, red, green and blue, which light up in different mixes to make every color. A faulty pixel is one where some or all of them stop following the picture. Which kind you have decides what you can do about it.
Dead pixel
A dead pixel stays dark on every color. It is easiest to see on the white screen, as a black dot. It is a hardware fault in the pixel itself and rarely recovers.
Stuck pixel
A stuck pixel has one or two subpixels stuck on, so it shows as a red, green, blue or mixed-color dot that doesn't change with the picture. Look for it on black, where any lit subpixel stands out. Stuck pixels sometimes recover, on their own or with a flashing tool such as our stuck pixel fixer.
Hot pixel
A hot pixel has all three subpixels stuck on, so it shows as a white dot on the black screen and vanishes on white.
Dust, scratches and pressure marks
Specks on the surface look soft and gray and move when you wipe them. A bright or dark cloud that covers many pixels is not a pixel fault: it is usually backlight bleed, a pressure mark or uneven backlighting, which the monitor test helps you check.
How many faulty pixels are allowed?
There is no single rule. Many makers base their policies on the pixel fault classes of the international standard ISO 9241-307, which replaced the older ISO 13406-2 in 2008. It sorts screens by how many faulty pixels they may have per million pixels, and counts three kinds separately: pixels that are always lit, pixels that are always dark, and faulty subpixels.
Class 0 allows no faulty pixels at all, and each class after it allows a few more. Under the older standard, Class II allowed up to 2 always-lit pixels, 2 always-dark pixels and 5 faulty subpixels per million pixels. A 4K screen has about 8.3 million pixels, so a handful of faults can still be within a limit like that.
Makers' own policies are often stricter for bright dots than for dark ones, and some brands and shops promise a screen with no faulty pixels at all. What you can do depends on the warranty terms and on where you bought the screen, so check the maker's pixel policy and your retailer's return policy, and test a new screen as soon as it arrives.
When you report a fault, copy the report from this page and add a photo of the dot on the color where it shows best. Say where it is on the screen, for example "about an inch from the top-left corner", so the support team can find it.
Problems with the test? Try these fixes
Full screen doesn't open, or closes right away
Browsers allow full screen only right after a click or a key press, and some extensions and screen tools block it.
Browser
- Reload the page and press Start the full-screen test again.
- Turn off extensions that change pages, such as dark mode or screen magnifier extensions, or try another browser.
- On an iPhone, web pages can't use full screen, so the colors fill the browser window. Turn the phone sideways for the biggest area.
The colors look dim, tinted or uneven
Night modes, automatic brightness and color filters change what you see, which can hide a faulty pixel or make the screen look patchy.
Windows 11
- Open Settings → System → Display and turn off Night light.
- On the same page, under Brightness, turn off automatic brightness while you test, and turn the brightness up.
macOS
- Open System Settings → Displays and turn off True Tone and Automatically adjust brightness, if your Mac has them.
- Click Night Shift and turn it off while you test.
Graphics and color software
- Turn off blue-light filter apps while you test.
- Reset color, saturation or vibrance settings in NVIDIA Control Panel, AMD Software or Intel's graphics app to their defaults.
I can't tell whether a dot is a pixel or dirt
- Wipe the spot gently with a dry microfiber cloth and look again.
- Look at the dot from an angle. Dust on the surface seems to shift against the pixels behind it; a faulty pixel stays in line with its neighbors.
- Check it on several colors. A faulty pixel is exactly one pixel wide and sharp-edged on every color it shows on.
A dot shows on some colors but not others
That is normal for a stuck subpixel. A stuck red subpixel can't be seen on red, white, magenta or yellow, which already use red, and stands out on black, green, blue and cyan. Note the colors it shows on: the tip on each color tells you which subpixel is at fault.
Common questions
What is the difference between a dead pixel and a stuck pixel?
A dead pixel stays dark whatever the screen shows, so it stands out on white. A stuck pixel has one or more of its red, green or blue subpixels stuck on, so it shows as a bright or colored dot that is easiest to see on black. Stuck pixels sometimes recover; dead pixels rarely do.
How do I check a new monitor for dead pixels?
Wipe the screen, open this test, press Start and step through every color in full screen. Scan the whole screen from about an arm's length, then look closely at anything suspicious. Do it while your retailer's return window is still open, since that is usually the easiest way to get a replacement.
How can I tell a dead pixel from dust?
Dust sits on the surface: it looks soft, gray and slightly out of focus, and it moves or disappears when you wipe the screen with a microfiber cloth. A dead or stuck pixel is a sharp dot one pixel wide that stays in exactly the same place on every color.
Is it normal for a new screen to have a dead pixel?
Many makers accept a small number of faulty pixels under their warranty terms, often based on the pixel fault classes of ISO 9241-307. Some brands and shops promise zero bright dots or replace a screen with any faulty pixel. Check your monitor's warranty terms and your retailer's return policy.
Can a dead pixel fix itself?
A pixel that stays black on every color is usually a hardware fault and rarely comes back. A stuck pixel that shows a color sometimes clears on its own after hours of use, or with a pixel-flashing tool such as our stuck pixel fixer. Neither is guaranteed.
Does this dead pixel test work on phones, laptops and TVs?
Yes. It works in current browsers on computers, phones and tablets. To check a TV, connect a computer to it and open this page on the TV, or use the TV's own web browser if it has one.
Something not right?
Tell us if your device wasn't found or a result looks wrong. Your browser, system and device model help us check.
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