Everything about dead and stuck pixels — what causes them, how to identify them, whether they spread, and how to test for them on any device.
Every pixel on your screen is made up of three sub-pixels — red, green, and blue (RGB). These sub-pixels are controlled by tiny transistors that switch them on and off at varying intensities to produce the full spectrum of colors you see. When all three light up at full brightness, you see white. When all three are off, you see black.
A dead pixel occurs when the transistor controlling a pixel permanently fails, leaving all three sub-pixels stuck in the off position. The result is a tiny, persistent black dot that remains visible no matter what color is displayed. These defects are most noticeable on light or white backgrounds.
Pixel defects can appear on any display — LCD monitors, OLED screens, laptops, phones, tablets, TVs, and even E Ink readers like the Kindle. They are a manufacturing defect and, unlike stuck pixels, are almost always permanent.
Try our dead pixel testPeople often use "dead pixel" and "stuck pixel" interchangeably, but they are different defects with different causes. Understanding the distinction matters because stuck pixels can often be fixed — while the dead variety usually cannot.
A dead pixel has a completely failed transistor. All three sub-pixels remain permanently off, producing a black dot visible on bright or white backgrounds. No amount of software cycling can bring it back.
A stuck pixel has a transistor locked in the "on" position for one or more sub-pixels, producing a tiny bright dot — commonly red, green, or blue. Because the transistor is still functional (just stuck), rapidly cycling colors can sometimes reset it. Stuck pixels are most visible on dark or black backgrounds.
| Feature | Dead Pixel | Stuck Pixel |
|---|---|---|
| Appearance | Black dot | Bright colored dot (R/G/B) |
| Cause | Transistor failure (off) | Transistor stuck (on) |
| Visible on | Light/white backgrounds | Dark/black backgrounds |
| Fixable? | Rarely — usually permanent | Often — try pixel fixer |
| Warranty eligible | Yes (varies by policy) | Sometimes (fewer accepted) |
Not sure which type you have? Try the stuck pixel fixer first — if it works, it was a stuck pixel. If it doesn't respond after 20-30 minutes of cycling, it's likely a permanent defect and may be covered under your manufacturer's warranty.
This is one of the most common concerns after discovering a dead pixel, and the short answer is: no, dead pixels do not spread. Each pixel operates independently with its own dedicated transistor. When one transistor fails, it has no connection to neighboring pixels that would cause them to fail.
However, there are situations where multiple defective pixels can appear over time, which creates the illusion of "spreading":
If you notice a single dead pixel, there's no reason to expect it will spread. But if you see multiple defects appearing in a short period, it could indicate a deeper hardware issue worth investigating under warranty.
Pixel defects can occur on any display technology. The testing process is similar across devices, but each has specific considerations. Set your brightness to maximum before testing — dim screens make it harder to spot defects.
Set brightness to maximum and cycle through all solid colors. Pay close attention to corners and edges, where pixel defects are more common due to panel mounting stress. For desktop monitors, also run the test in a dark room to check for backlight bleed — uneven glow around the edges that can indicate panel quality issues.
Open the dead pixel test in your mobile browser and set brightness to maximum. Tap to cycle through colors. On OLED phones (most modern iPhones, Samsung Galaxy, Google Pixel), also check for screen burn-in by displaying a uniform gray — ghost images from the status bar or navigation buttons indicate OLED aging.
Tablets have more display area than phones, which statistically increases the chance of pixel defects. Max your brightness, open the test in Safari or Chrome, and inspect methodically from corner to corner. Mini-LED iPads (iPad Pro) and OLED tablets should also be checked for burn-in. Run a full screen test for the most thorough inspection.
For TVs, open the test in the built-in browser or cast it from your phone. Test in a dark room for the best visibility — ambient light washes out subtle defects on large panels. For Kindle and E Ink readers, the defects behave differently: they appear as dots that never refresh during page turns. E Ink pixel failures are permanent and not fixable with cycling tools.
Follow these three steps to thoroughly test any screen for dead or stuck pixels. The entire process takes about 2-3 minutes.
Use a microfiber cloth to gently wipe your screen. Dust and smudges can look like pixel defects, so starting with a clean display ensures accurate results. Avoid paper towels or rough fabric that can scratch the panel.
Open the dead pixel test tool and cycle through each solid color — black, white, red, green, blue, cyan, yellow, and magenta. Each color reveals different types of defects. White reveals dead pixels; black reveals stuck ones.
Lean in to about 6 inches from the screen and carefully scan the entire display on each color. Check corners and edges where defects are most common. The dead variety appears as black dots on bright colors; stuck pixels show as colored dots on dark backgrounds.
Found a stuck pixel? Try our stuck pixel fixer — it rapidly cycles colors to reset the stuck transistor. Run it for 20-30 minutes for the best results. If the pixel doesn't respond, check your warranty options.
Use our free tools to check for pixel defects, fix stuck pixels, test for burn-in, and run a full screen diagnostic — all from your browser.