Dead Pixel Test

How to use

1. Go full screen. Click Full screen so a single solid color fills the whole display with nothing else on screen.
2. Cycle the colors. Click or use the arrow keys to switch colors, or turn on Auto-cycle to let it rotate for you.
3. Look closely. Scan the screen on each color. A magnifier or your phone camera helps. The dot that won't match the fill is the one you're hunting.

Why test this

A single bad pixel blends into normal content. Once you spot it, you can't unsee it. The only way to find one reliably is to flood the screen with a clean, full-field solid color and look. A black field reveals stuck and hot pixels glowing their own color, while bright fields like white, red, green, and blue reveal dead pixels that stay stubbornly black. Run this the moment a new monitor, laptop, or phone comes out of the box, while you can still return it. Most manufacturers permit a handful of bad pixels before a panel counts as defective, so knowing the count early matters. It's also worth a check on a used display before you buy, where a hidden dead pixel is a quiet bargaining point or a reason to walk away.

What the results mean

What you're looking for is one tiny dot that refuses to match its surroundings. On the bright fills (white, red, green, blue, cyan, magenta, yellow) a dead pixel reads as a persistent black speck no matter which color is showing. On the black fill, a stuck pixel does the opposite and glows red, green, or blue while everything around it stays dark. A subpixel fault may only appear on one or two colors, which is why cycling through all of them matters, so use Auto-cycle and watch the same spot across the set. Get close, or use your phone camera or a magnifier, since a single pixel is smaller than it sounds. A stuck pixel is sometimes fixable, but a dead one almost never comes back.

FAQ

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

A dead pixel stays black on every color. It gets no power at all. Stuck pixels are locked to one color, often red, green, or blue, and show against the others. Hot pixels are the opposite: all subpixels fire at once, so the dot stays bright white and stands out against a dark field.

Can a stuck pixel be fixed?

Sometimes. Gently massaging the spot with a soft cloth, or running fast color changes over it for a while, can exercise the subpixel and free it. A truly dead pixel rarely recovers.

How many dead pixels are normal?

Manufacturers set a limit under ISO 9241-307, and it depends on the panel's defect class and the brand. Some premium panels carry a zero bright dot guarantee that covers a single stuck pixel, while budget displays often allow several. Check your warranty for the exact count.

Why didn't I see the pixel until I went full screen?

A single bad pixel is tiny and easy to miss among normal content. A clean, full-screen solid color is the only background where it stands out.

Is this dead pixel test free?

Yes, and nothing to download. The color fills run in your own browser, so the test works offline once loaded and saves nothing about your screen.

Embed the dead pixel test on your site

Writing a monitor buying guide or a return checklist? Add the dead pixel test so readers scan a new panel for stuck pixels before the window closes. One snippet, full-screen ready, share the result in a tap.

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