Microfiber screen cleaning kit
Rules out dust and smudges before you decide a dot is a pixel.
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Dead Pixel Test
Fill your screen with solid colours and scan for pixels that don't change. It takes about a minute and works on any monitor, laptop or phone browser.
The screen will fill with one colour at a time. Click or press → for the next colour, ← to go back, Esc to exit.
Or start on a single colour. The cycle never flashes.
Runs in your browser. Nothing leaves this page.
Quick answer
Press Start, then click or press → to move through black, white, red, green, blue and gray. A dot that stays dark on white is dead; a coloured dot on black is stuck; a white dot on black is hot. Press Esc to exit.
How to use the Dead Pixel Test
Clean the screen
Wipe it with a soft dry cloth so dust isn't mistaken for a pixel.
Start the test
Press Start. Click, or use the arrow keys, to change colour. Look closely at each one, edges and corners included.
Note what you see
Mark any dot that doesn't match the screen. Use the table below to see what it is and what to do.
How the dead pixel test works
A screen is a grid of tiny pixels, each made of red, green and blue sub-pixels. A pixel that works changes colour with the screen. A pixel that doesn't shows up as a dot that stays the same while everything around it changes. Showing a plain full-screen colour makes any such dot easy to see against an even background.
Start the test and the page fills your screen with one colour at a time. Press → or click for the next colour, ← to go back, and Esc to exit. You can turn on auto-cycle to change colour every 3 seconds, which is slow and does not flash. The pointer is hidden during the test.
Dead, stuck and hot pixels
What you see depends on the type of fault. Check each colour, since some faults only show on one.
| Type | What it looks like | Seen best on | What to do |
|---|---|---|---|
| Dead pixel | A black dot that stays dark | White | Check your retailer's or maker's policy; dead pixels usually can't be fixed. |
| Stuck pixel | A dot stuck on red, green or blue | Black | Sometimes fades. Check the maker's policy if it stays. |
| Hot pixel | A white dot that stays lit | Black | Treated like a stuck pixel. |
| Dust or smudge | A dull spot that wipes away | Any | Clean the screen and test again. |
If you find one: a return and warranty checklist
- Take a clear photo of the dot on a plain background, with the colour that shows it.
- Count the faults and note where they are. Many makers allow a small number before they accept a claim, and the rules differ, so look for the pixel policy on the maker's or seller's site.
- Check the return window with the seller. A new monitor is easiest to return soon after delivery.
- Keep the box, receipt and serial number until you're sure.
- Test again after a day. A hot or stuck pixel can fade.
We don't offer a pixel "fixing" flashing mode on this page. Rapid flashing can be uncomfortable for people sensitive to flicker, and results are inconsistent.
Gear that helps
Category searches on Amazon, picked because they relate to what this tool checks. Compare options and read the listing before you buy.
Gaming monitor
Check the maker's dead pixel policy and the return window before you buy.
Search on AmazonMonitor arm
Makes it easy to tilt the screen and check it from different angles.
Search on AmazonAmazon Associates affiliate links: we earn from qualifying purchases. See our affiliate disclosure.
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Frequently asked questions
How do I test for dead pixels?
Press Start and cycle the full-screen colours. Look closely at each one for a dot that doesn't change with the rest of the screen. White shows dead pixels best, and black shows stuck and hot ones.
What is the difference between a dead and a stuck pixel?
A dead pixel is off and shows black. A stuck pixel is always on one colour, such as red, green or blue. A hot pixel is always white.
Can dead pixels be fixed?
Dead pixels usually can't. Stuck pixels sometimes fade on their own. If a fault is covered by the maker's policy, a return or replacement is the usual route.
How many dead pixels are acceptable?
It depends on the maker and the display class, and policies differ. Check the pixel policy on the manufacturer's or seller's site rather than relying on a general number.
Does this test work on a phone or laptop?
Yes, on any screen with a modern browser. Fullscreen is not available in every browser, so the colour covers the viewport instead.
Is the colour cycle safe?
Auto-cycle changes colour every 3 seconds and does not flash. It is off by default. Stop at any time with Esc.
Is anything uploaded?
No. The test runs entirely in your browser.
This article reflects independent editorial research and disclosed buying criteria, not hands-on lab testing or manufacturer sponsorship. Some links on this page are Amazon Associates affiliate links; see our affiliate disclosure.