Dead Pixel Test — Check Your Screen Full Screen
Pick a color or start the sequence. Tap or click for the next color — the same tap brings back the bar with its close button, and the Escape key also exits.
About the Dead Pixel Test
A dead pixel is a point on your screen that no longer lights up, so it stays black no matter what is displayed. A stuck pixel is the opposite: it is jammed on in red, green or blue and never turns off. Both are almost invisible during normal use because photographs and web pages give the eye too much to look at — but on a plain field of color they stand out immediately.
That is all this test does. It fills the entire screen with one solid color at a time and gets out of the way. A white field reveals dead pixels as black specks. A black field reveals stuck pixels as bright dots. The primary colors in between catch pixels where only one of the three subpixels has failed, which shows up as a colored dot rather than a black or white one.
Work through all nine colors and look carefully across the whole panel, including the edges. Dust on the surface can look exactly like a stuck pixel, so wipe the screen before deciding.
How to check for dead pixels
- Wipe the screen first. A speck of dust looks exactly like a stuck pixel.
- Set brightness to a normal level and turn off night-light or blue-light filters. They tint the whole screen and hide the colored dots this test is looking for.
- Press the start button to fill the screen. Allow full screen if the browser asks.
- Look over the whole panel, edges included. Move close enough to see individual pixels.
- Click or tap to move to the next color, and repeat the sweep for each one.
- Note where any faulty pixels sit. When you are finished, tap to bring back the close button, or press Escape.
Frequently asked questions
What is the difference between a dead pixel and a stuck pixel?
A dead pixel receives no power and stays black on every color. A stuck pixel is permanently on and shows as a bright red, green, blue or white dot. Stuck pixels sometimes recover on their own or with gentle massage; dead ones essentially never do.
Can I fix a stuck pixel?
Sometimes. Rapidly cycling colors in that area for a few minutes, or very gently massaging the spot with a soft cloth through a screen protector, occasionally frees it. Neither is guaranteed, and pressing hard risks making the damage permanent and worse.
How many faulty pixels before I can claim a warranty?
It depends on the manufacturer and the class of panel — the classes come from ISO 9241-307, which replaced the older ISO 13406-2 that many warranty pages still name. Many warranties only take effect above a threshold — several faulty pixels, or a single one in the center of the screen. Check your manufacturer's stated pixel policy before contacting support.
Why should I be careful with an OLED screen?
OLED panels can retain a static bright image if it is displayed for a long period. Move through the colors rather than leaving one white field on screen for many minutes, and this test poses no risk.
Some pixels near the corner are hidden. Is that a fault?
No. Phones and some laptops have rounded corners or a camera cutout, and the pixels behind those areas are simply not visible. No test can reach them, and their absence is by design rather than a defect.
Does this test send anything about my screen anywhere?
No. The tool only changes a background color in your browser. Nothing about your display is measured, transmitted, or stored.
Is the Dead Pixel Test free, and do I need to download anything?
Free, with no account and no download. It matters here more than most: a dead pixel check is something you do in a shop before buying, or on a delivery inside the return window, and neither moment lets you install a utility on a machine that is not yours yet.
What should I do before I start looking?
Clean the screen first — dust and a dried splash both look exactly like a stuck pixel, and most reports turn out to be one of the two. Then dim the room, set the display to its native resolution, and go full screen so the browser's own interface is not sitting over part of the panel you need to inspect.