How to run the dead pixel test
- Wipe the screen with a dry microfiber cloth first. A speck of dust looks exactly like a dead pixel.
- Press Start dead pixel test. The screen fills with one solid color and the cursor hides.
- Scan the whole screen slowly, edge to edge. Then click, or press Space or →, for the next color. ← goes back and Esc exits.
- Found something? Press M and click the spot. Its position is saved to the defect list for your report.
On a phone or tablet, tap to advance and use the on-screen buttons, which reappear whenever you touch the screen. Many phones can’t hide the browser bar, so rotate to landscape and scroll the page slightly first.
Dead, stuck or hot pixel?
Each pixel is made of three sub-pixels: red, green and blue. The color of the dot, and the backgrounds it shows up on, tell you what failed.
| Defect | What you see | Best screen to spot it | Fixable? |
|---|---|---|---|
| Dead pixel | A black dot that never lights | White, red, green, blue | Rarely. The transistor has failed. |
| Stuck pixel | A red, green, blue, cyan, magenta or yellow dot that never changes | Black, then the other colors | Often. Try the fixer. |
| Hot pixel | A white dot, all three sub-pixels always on | Black | Sometimes |
| Dead sub-pixel | A colored dot on white, for example cyan when red is dead | White | Rarely |
How to read each test color
- Black shows stuck and hot pixels as bright dots. It also shows backlight bleed and IPS glow. For a longer look, use the black screen tool.
- White shows dead pixels as black dots. A dot in a single color means one sub-pixel won’t light.
- Red, green and blue isolate the sub-pixels. On red, a black dot is a dead red sub-pixel (or a dead pixel). A yellow or magenta dot means the green or blue sub-pixel is stuck on.
- Gray shows dark and bright defects at once, plus blotchy uniformity (“dirty screen effect”).
- Gradient should be a smooth ramp. Visible steps or clouds point to the panel or its settings, not individual pixels.
Fixing a stuck pixel
Mark the pixel, then use the fixer: accept the warning, press Fix next to the defect (or open the fixer and drag the square over it) and let it run for 10 to 20 minutes. Rapidly switching the sub-pixels sometimes frees one that’s stuck. If it doesn’t work, try again with a longer session. Some stuck pixels never recover, and a dead (black) pixel won’t respond at all. Avoid pressing on the screen: it can create new defects and may void your warranty.
Returns and warranty
Test a new monitor, TV or laptop as soon as it arrives. Store return windows are often shorter than the warranty and usually easier. Manufacturers publish pixel policies that allow a small number of defects. Many are based on the old ISO 13406-2 Class II standard, which allows up to 2 always-lit, 2 always-dark and 5 sub-pixel defects per million pixels. Premium lines often promise “zero bright dots”. Use the report above (count, positions, screen size) and your photos when you contact support. Testing a new laptop? Also run the keyboard tester, and check a new high-refresh monitor with the refresh rate test.
Frequently asked questions
How do I check my monitor for dead pixels?
Clean the screen, press Start dead pixel test and look over each full-screen color from edge to edge. Dead pixels show as black dots on the white and colored screens; stuck and hot pixels show as bright dots on black. Press M and click a defect to record its position.
What is the difference between a dead pixel and a stuck pixel?
A dead pixel is always off, so it looks black on every color. A stuck pixel has one or more sub-pixels always on, so it shows as a red, green, blue or mixed-color dot, easiest to see on black. A hot pixel is all sub-pixels stuck on and looks white.
Can a dead pixel be fixed?
Usually not. A truly dead (black) pixel has a failed transistor. Stuck pixels are different: rapidly flashing colors over them, as the fixer does, sometimes frees them. Try 10 to 20 minutes, and repeat a few times if it doesn't work the first time.
Is the stuck pixel fixer safe?
It can't damage a modern LCD or OLED screen; it only changes colors quickly, like fast-moving video. It does flash rapidly, so don't use it if you or anyone who can see the screen has photosensitive epilepsy, and don't stare at it while it runs.
How many dead pixels are acceptable on a new monitor?
It depends on the manufacturer's pixel policy. Many follow the old ISO 13406-2 Class II standard, which allows up to 2 always-lit, 2 always-dark and 5 sub-pixel defects per million pixels. Some brands and stores promise zero bright dots, so check yours and your return window.
Is it a dead pixel or just dust?
Wipe the screen with a dry microfiber cloth and test again. Dust usually looks soft or slightly out of focus and can move when you wipe. A dead or stuck pixel is a sharp, perfectly square dot that stays in the same place on every color.
Does the test work on phones, tablets and TVs?
Yes. It runs in any modern browser. Tap to go to the next color and use the on-screen buttons to go back, mark a defect or exit. Some phones, including iPhones, keep the browser bar visible, so turn the phone to landscape to see more of the screen.