WhitestScreen

Dead Pixel Test

A free fullscreen dead pixel test that cycles pure red, green, blue, white, and black so stuck or dead pixels stand out.

By , WhitestScreen.com

Colors
Repair mode

Found a stuck (colored) pixel, not a dead (black) one? This rapidly cycles colors over that spot to try to "exercise" it back into working order.

Not guaranteed. Works on stuck pixels only, never on truly dead ones.

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This dead pixel test cycles through solid white, black, red, green, and blue so you can spot dead or stuck pixels on any screen. A dark dot on a bright background is usually a dead pixel; a colored dot on black is usually a stuck one, which sometimes responds to the repair mode below. It's free, runs instantly in your browser, and doesn't require an account or download.

How to test properly

  1. Clean your screen first, since dust and fingerprints are easy to mistake for pixel defects.
  2. Darken the room if you can.
  3. Tap Fullscreen, then cycle through every color using the swatches, Auto-cycle, or your keyboard (Space or the right arrow for the next color, the left arrow to go back). Testing white alone isn't enough. Colored stuck pixels are much easier to see against black.
  4. Note the position of anything you find, then compare it against a few colors to confirm it's consistent.
  5. If it's a colored (stuck) pixel, try Repair mode. If it's black on every color (dead), repair mode won't help.

Thinking about a return?

Check your return window first

Many retailers give you a short window, sometimes as little as 48 hours from delivery, to report a defective screen for an easy return, separate from a longer manufacturer warranty process. Test as soon as your device arrives, not weeks later.

Defects near the center often count more

Retailers commonly apply a stricter standard to defects in the middle of the screen than near the edges, since they're more noticeable in everyday use. A single central defect can sometimes qualify for return even when the total count wouldn't.

Manufacturers generally set their replacement thresholds using the ISO 9241-307 pixel-defect classification system, but the exact number of pixels that qualifies varies by retailer and can change over time. Check your specific seller's current policy rather than a number you saw somewhere else. See our full new monitor defect checklist for a step-by-step walkthrough.

Frequently asked questions

What's the difference between a dead pixel and a stuck pixel?
A dead pixel stays black on every color you test, because its sub-pixels are permanently off. A stuck pixel stays lit on one color, usually red, green, or blue, regardless of what color the screen is showing. Only stuck pixels can sometimes be fixed with the repair mode.
Does the repair mode actually work?
Sometimes, on stuck pixels only, and only sometimes. It rapidly cycles colors to try to "exercise" the stuck sub-pixel back into working order. It has no effect on a pixel that's actually dead, and there's no guarantee it will fix a stuck one.
How many dead pixels are considered acceptable for a return?
It depends entirely on the retailer and manufacturer, and policies change over time, so there's no single universal number. Many sellers reference the ISO 9241-307 pixel-defect classification system. Check your specific retailer's current return policy rather than relying on a number you saw elsewhere.
I only tested with a white screen — could I have missed something?
Yes. A white screen only reveals dark (dead) pixels clearly. Stuck pixels showing red, green, or blue are much easier to spot against black. Always cycle through white, black, red, green, and blue before deciding your screen is clean.
What's a hot pixel?
A hot pixel stays lit bright white regardless of what color the rest of the screen shows, unlike a stuck pixel, which locks onto a single color. It's the least common of the three defect types and isn't fixable through the repair mode.

Not sure this is your actual problem? Start with the full screen defect triage guide →

Cedrick Reese built this dead pixel test. Auto-cycle steps through white, black, pure red, green, and blue, then cyan, magenta, and yellow, because a stuck subpixel only shows against colors that switch it on or off. Repair mode flashes pure red, green, blue, white, and black rapidly, a common unsticking method that helps some stuck pixels and does nothing for dead ones, as the FAQ says. The colors are fixed values in the page, with no outside data to go stale.

About the creator

WhitestScreen.com was founded by Cedrick Reese, a retired veteran and web developer who enjoys building free, user-friendly online tools that simplify everyday tasks. More about Cedrick Reese →