Dead Pixel Test
Cycle fullscreen colors to find dead and stuck pixels on any screen.
Wipe your screen first — dust looks exactly like a dead pixel. In fullscreen: click, tap or use ← → to change color, Esc to exit.
Click / → next color · Esc to exit
How it works
The test fills your entire screen with a sequence of solid colors: white, black, and the pure primaries and secondaries. Each color isolates a different failure. On black, any bright dot is a stuck sub-pixel that is on when it should be off. On white, any dark dot is a dead pixel whose transistor no longer fires. On pure red, green and blue, a dot that stays dark reveals which individual sub-pixel has failed — a pixel dead only on red has a failed red sub-pixel.
Scan the whole screen slowly at each color, corners included, from about 30cm away. A dead pixel (black on all colors) is permanent hardware failure — check your panel's warranty pixel policy. A stuck pixel (frozen on one color) can sometimes be revived with gentle massage or rapid color cycling — the difference and the revival techniques are covered in our dead vs stuck pixel guide. For broader panel issues like backlight bleed or banding, continue to the monitor test suite.
Dead pixel vs stuck pixel: what you are looking at
This test fills your whole screen with one solid color at a time. Against a flat field, a single misbehaving pixel is obvious — it is the one dot that stays the wrong color. The color it fails on tells you exactly what kind of defect it is, and whether it is worth trying to fix.
How to tell them apart
| What you see | Type | Fixable? |
|---|---|---|
| Black on every color, including white | Dead pixel (no power to the pixel) | No — hardware, cannot be revived in software |
| Stuck on red, green or blue | Stuck pixel (a sub-pixel frozen on) | Sometimes — see the revival steps |
| Bright white dot on a black field | Hot pixel (sub-pixels stuck full on) | Sometimes |
| A cluster or line | Panel/connector damage | No — warranty or repair |
Which colors to cycle through
Check black (reveals bright/stuck pixels), white (reveals dead ones), then pure red, green and blue to isolate each sub-pixel. A pixel that looks fine on white but wrong on red has one dead red sub-pixel — a partial defect. Clean the screen first: dust and grease mimic dead pixels and wipe right off.
Trying to revive a stuck pixel
- Gently massage the exact spot with a soft, dry microfiber cloth for 10–15 seconds — light pressure only.
- Run a rapidly flashing color pattern over the pixel for 10–30 minutes to exercise the sub-pixels.
- Repeat once or twice. Stuck pixels sometimes free up; dead pixels never will.
Is it covered by warranty?
Manufacturers publish a "pixel policy" with a defect threshold — often several dead sub-pixels before a panel qualifies for replacement, with brighter stuck pixels judged more strictly than dark ones. Photograph the defect against a solid field and check your vendor's exact policy before the return window closes.
Troubleshooting
› I found a pixel that is always black
A pixel dark on every color is dead — its transistor no longer drives the sub-pixels. It cannot be fixed in software. Check your warranty; many panels are covered above a defect threshold.
› I found a pixel stuck on red, green or blue
That is a stuck pixel, and unlike dead pixels these sometimes recover. Gentle massage over the spot with a soft cloth, or leaving a rapidly flashing pattern on it, occasionally revives them.
› Fullscreen won’t open
Some browsers block fullscreen requests until you interact with the page — click the start button rather than using a keyboard shortcut. On iPhone, Safari does not allow true fullscreen; scroll the browser chrome away instead.
Frequently asked questions
› What is the difference between a dead and a stuck pixel?
A dead pixel stays black on every color. A stuck pixel is frozen on one color (red, green or blue). Stuck pixels can sometimes be revived; dead ones cannot.
› Which colors should I check?
All of them. Black reveals bright/stuck pixels, white reveals dead ones, and pure red, green and blue isolate each sub-pixel.
› Does this work on phones and TVs?
Phones and tablets, yes — open this page in the device’s browser. For TVs, open the page in the TV’s browser or cast a solid-color video.
› Is one dead pixel covered by warranty?
Policies vary: many manufacturers require a minimum number of defects before replacing a panel. Check your vendor’s pixel policy — bright (stuck) pixels are often treated more strictly than dark ones.