Dead & Stuck Pixel Test

A pixel that never lights up at all, so it shows as a small dark or black dot no matter what color is displayed behind it — it isn't receiving any signal, which is why it can't be fixed by software.

A stuck pixel is locked showing one color (commonly red, green, or blue) instead of matching whatever's actually being displayed — unlike a dead pixel, it is receiving power, which is why stuck pixels have a real chance of being fixed and dead pixels don't.

A less common term for a stuck pixel that's permanently locked fully bright (usually white) rather than a single color — same underlying cause and same fix options as any other stuck pixel.

Not by definition — a dead pixel is one that isn't lighting up at all, so it shows as a dark or black dot on any color, LCD or OLED alike. A persistent bright white (or colored) spot that never changes is a stuck or "hot" pixel instead, which is a different fault with a real, if not guaranteed, chance of being fixed.

On an LCD panel, it's usually a failed transistor for that one pixel, which can't be revived by software. The failure itself often traces back to a manufacturing defect that was already present but not visible, only surfacing later after heat, humidity, physical pressure, or power stress pushes it past the point of working — rather than a defect that develops purely from normal use.

An individual dead pixel doesn't spread — one failed transistor doesn't cause the pixel next to it to fail. But if the underlying cause (heat, pressure, an impact, a manufacturing weakness in that panel) is still present, it's possible for separate new defects to appear elsewhere on the same display over time — that reads as "getting worse," but it's new individual failures, not one pixel growing.

No — it's a hardware fault (a failed transistor with no signal reaching it), not a temporary glitch, so it won't resolve on its own. A stuck pixel is the one worth actively trying to fix, using this tool's fixer or the massage method above.

Generally no — since it isn't receiving any signal at all, there's nothing for software or a physical technique to act on. If a new or recently purchased device has one, checking the seller's return policy is usually the more realistic path than trying to repair it.

For a monitor or laptop screen, professional repair commonly runs somewhere in the $50-200 range; phone screen replacement for this specific issue is often pricier, roughly $130-220 depending on the model. Since a genuinely dead pixel usually means replacing the whole panel rather than repairing one spot, checking whether it's still covered by warranty is almost always worth doing before paying for a repair out of pocket.

Since the underlying cause is often a latent manufacturing weakness that heat, humidity, physical pressure, or power stress can push into failing, the realistic prevention steps are handling the panel carefully (no pressing on the screen, including through a bag), keeping the device out of extreme heat or humidity, and buying from a seller with a clear return policy so a defect that shows up early is still covered. There's no way to fully guarantee a panel will never develop one — this test is really about catching it early, not preventing it outright.

Sometimes. The built-in fixer here rapidly flashes red, green, blue, white, and black over wherever you drag it to, to exercise the stuck sub-pixel loose — drag it directly over the spot and leave it running, typically for many minutes to an hour, with your screen saver and auto-lock turned off. There's also a physical "massage" method (gentle, even pressure on the spot through a soft cloth) that works for some LCD panels, but it's not guaranteed and carries real risk if overdone.

On an LCD panel, light and careful pressure is a commonly reported (though not guaranteed) fix. On OLED, never try this — pressing on an OLED panel can permanently damage its organic light-emitting layers, and there's no equivalent "unstick" mechanism to justify the risk. Too much pressure on any panel can also crack the screen or damage surrounding pixels. The same OLED caution applies to the software fixer here too, out of caution, even though it's a much gentler technique than physical pressure.

Both — the main test cycles full-screen colors so you can visually spot a dead or stuck pixel, and "Try to fix a stuck pixel" gives you a flashing box you drag directly over the spot and leave running. It only has a real chance of helping a stuck pixel, not a dead one (a dead pixel has no signal reaching it for any flashing pattern to work with).

It varies by manufacturer, but many follow ISO 13406-2's Class II tolerance, which permits a small number of pixel defects on a display before it's considered faulty — commonly around 1-2 dead pixels depending on the panel's resolution and the manufacturer's specific policy. As a rough rule of thumb, one dead pixel often isn't enough on its own for a return or warranty claim, while two or more commonly is — but always check the seller's or manufacturer's actual stated policy rather than assuming a number, and test immediately after unboxing so you're still inside the return window if you find one.

They're unrelated problems. A dead or stuck pixel is a single hardware defect present from manufacturing or damage. Burn-in is a gradual, usage-based effect specific to OLED and other emissive panels, where static content displayed for very long periods leaves a faint permanent ghost image — it isn't something a color-cycling test like this one is designed to catch.

The full-screen color cycle works fine for spotting a dead sub-pixel on any panel type, OLED included. The fixer is a different story — stick to LCD panels only; skip it on OLED, where a stuck pixel is a rarer and different kind of fault and there's no equivalent benefit to justify running it.

Backlight bleed is light leaking in from the edges or corners of an LCD panel, visible mainly on a full-screen black image in a dim room — it's a panel/backlight assembly issue, not a single failed pixel, and shows as a patch of glow rather than a tiny dot.

Yes — the same full-screen color cycle works on any device with a browser, phone and tablet included, though full-screen mode support varies slightly by mobile browser.

This tool works fine on Samsung's browser too, but Samsung phones also have a built-in hardware diagnostic: dial *#0*# from the Phone app to open the service menu, then tap Red, Green, or Blue to fill the screen with each color the same way this tool does. It's carrier- and model-dependent, so it won't work on every device, but it's a genuine manufacturer-level test when it's available.

No, despite the identical name — they're different failure domains. A screen dead pixel is a display hardware fault you can see, which this tool tests for. A camera sensor dead pixel is a defective photosite on the image sensor that can leave a spot on photos; camera manufacturers test for and "map out" these during manufacturing, and most cameras also have a built-in pixel-mapping or sensor-cleaning feature to handle new ones — a screen test like this one doesn't check for that at all.

No — displaying solid colors is completely normal screen operation and puts no unusual strain on the panel. It's the same thing any image or video does.

It's a strong, standard visual check for dead pixels, stuck pixels, and backlight bleed, but it isn't a lab measurement — very small or edge-of-panel defects can still be easy to miss with the naked eye, so a careful, well-lit scan of the whole panel matters more than speed.