Your screen has a dot that never changes. It might be black no matter what you display. It might glow one color constantly. It might be a pinpoint of intense brightness only visible in a dark room. These are three different failures with different causes and different outcomes. Treating a stuck pixel like a dead pixel means abandoning a fix that might have worked.
The dead pixel test runs your screen through solid black, white, red, green, and blue backgrounds in fullscreen. Each color exposes a different failure type. Run it before drawing any conclusions about what you are dealing with.
What Is a Dead Pixel?
A dead pixel has a completely failed transistor. Each pixel on an LCD screen is controlled by a thin-film transistor (TFT) that regulates the voltage applied to the liquid crystal cell behind it. When the transistor fails permanently, it cannot pass any signal to the liquid crystal. The crystal stays in its default untwisted state, blocking the backlight entirely. The result is a pixel that displays as black regardless of what the rest of the screen shows.
Dead pixels are hardware failures. No software can restart a failed transistor. The pixel is permanently off.
On OLED displays, the failure mechanism is different: individual organic light-emitting elements degrade over time, particularly under high-brightness sustained use. An OLED dead pixel appears as a black dot where the organic material has burned out rather than where a transistor has failed, but the visual result and the permanence are the same.
Dead pixels are most visible against light or colored backgrounds. On a pure white screen, a dead pixel appears as a small black dot. They are invisible against a black background because the screen around them is also black. The dead pixel test uses a white fullscreen background first specifically to expose this failure type.
What Is a Stuck Pixel?
A stuck pixel has a functioning transistor but a liquid crystal cell frozen in one state. The transistor is sending signal, but the liquid crystal is not responding to it.
LCD pixels work by applying voltage to liquid crystal molecules, which twist or untwist to allow different amounts of backlight through. Normally, liquid crystals move freely in response to voltage changes. When a crystal freezes, it stays twisted or untwisted at one angle regardless of the voltage applied. The result is a pixel that displays one fixed color, typically red, green, blue, white, or a combination, regardless of what the screen should be showing.
Stuck pixels can appear in any color depending on which subpixels are frozen and in what state. A pixel stuck at full red, green, and blue simultaneously appears white. A pixel stuck at only the blue subpixel on a black background appears as a small blue dot.
Unlike dead pixels, stuck pixels sometimes recover. The liquid crystal is not damaged; it is frozen. Mechanical stress from rapid voltage cycling can sometimes dislodge the crystal and restore normal movement. This is the basis for stuck pixel recovery tools.
Run the stuck pixel fixer over the affected pixel area. The tool cycles rapidly through multiple colors, changing voltage across the pixel many times per second. Leave it running for 20 to 30 minutes. If the stuck pixel recovers during this process, you will see it change color or disappear into the normal image. If there is no change after 30 minutes of continuous cycling, the transistor has likely also failed and the pixel is not recoverable through software.
What Is a Hot Pixel?
A hot pixel is a subpixel that is always fully on, producing maximum brightness regardless of the displayed content. Where a dead pixel is always black and a stuck pixel is always one specific color, a hot pixel is always bright.
On screens, hot pixels appear as small, intensely bright red, green, or blue dots. They are most visible on dark or black backgrounds and may not be noticeable at all during typical daytime use with bright content. Switch the display to a solid black fullscreen to check for hot pixels, as they will appear clearly against the dark background while being invisible during normal use.
On digital camera sensors, hot pixels are a separate but related phenomenon. Camera sensors convert light to electrical signal through photodetectors, and some detectors become thermally activated even in the absence of light. These hot photodetectors produce signal that reads as a bright pixel in the resulting image, appearing most clearly in long exposures and high-ISO shots where the amplification of signal also amplifies the hot pixel output. Many cameras include a sensor mapping function in their firmware that identifies and ignores known hot pixel positions during processing.
The term "bright pixel" is sometimes used interchangeably with hot pixel, particularly in camera contexts. Both refer to always-on output rather than the always-off characteristic of a dead pixel.
How to Identify Which Type You Have
The identification method is the same for all three failure types: run a fullscreen test across multiple solid color backgrounds and observe what the defective pixel does on each.
Open the dead pixel test and press F11 or your browser's fullscreen command to fill the entire display. Cycle through each test color and note what the suspect pixel does.
Dead pixel identification:
- Appears black on white background
- Appears black on all color backgrounds (red, green, blue)
- Invisible on black background
Stuck pixel identification:
- Shows one fixed color regardless of background
- On a red background, a green-stuck pixel appears as a green dot
- On a white background, a stuck pixel at full brightness appears white (harder to see)
- Test on the black background first: stuck pixels glow visibly against black
Hot pixel identification:
- Appears as an intensely bright dot, visible clearly on black background
- May be imperceptible during normal use with bright content
- The brightness is noticeably higher than surrounding pixels even when the screen should display that area as bright
Subpixel defect identification:
- Appears as a color tint rather than a solid colored dot
- A red subpixel failure causes cyan tinting on white backgrounds (green + blue remaining)
- A green subpixel failure causes magenta tinting
- A blue subpixel failure causes yellow tinting
- Run all color backgrounds to identify which subpixel is affected
What Are Manufacturer Dead Pixel Policies?
Screen manufacturers set different thresholds for what qualifies as a warranty defect. Understanding the standard your screen was shipped under tells you whether you have grounds for a replacement.
The ISO 13406-2 standard classifies displays into quality tiers (Class I through Class IV) with defined acceptable defect counts per million pixels. Most consumer LCD monitors are shipped under Class II, which permits up to 2 type-1 defects (always-black pixels) and 2 type-2 defects (always-bright pixels) per million pixels on a 1080p display (roughly 2 million pixels), meaning up to 4 defective pixels may be within tolerance.
Apple applies a stricter policy than ISO 13406-2 for Macs and iPhones. A single dead pixel near the center of a MacBook display is typically sufficient for a warranty replacement under Apple service guidelines, regardless of whether the pixel count falls within ISO tolerance. Apple evaluates location and visibility rather than applying a fixed count threshold.
Samsung and LG consumer monitors commonly apply the ISO Class II standard. Their warranty documentation typically states that a small number of defective pixels is not a defect covered under warranty. For gaming monitors and professional panels, policies are often stricter with "zero dead pixel" guarantees applying to specific product lines.
For warranty and policy specifics by device type, the dead pixel warranty and policy guide covers manufacturer thresholds and how to document a pixel defect claim.
Why Do Pixels Fail?
Understanding the cause of failure helps determine whether it is isolated or part of a pattern.
Manufacturing defects produce dead or stuck pixels present from the day the display is turned on. These occur during the thin-film transistor fabrication process when a transistor is formed with a structural flaw or when the liquid crystal fill is imperfect at a specific cell. Manufacturing defects are static: the pixel fails immediately and does not spread.
Physical pressure causes pixels to fail when the display panel is squeezed between a hard object and the glass. Carrying a laptop in a bag with something pressing against the lid, or closing the lid with an object on the keyboard, can create pressure zones where pixels fail. These failures appear in clusters or lines rather than isolated single pixels.
Transistor degradation occurs over years of use as the electrical characteristics of thin-film transistors slowly change. High-temperature operation accelerates this process. Pixels failing from age-related transistor degradation tend to appear one at a time over months and years, typically starting in heavily used screen areas.
Backlight pressure on IPS panels can create stuck pixels in specific regions under thermal expansion. IPS panels are more susceptible to this because the liquid crystal alignment requires very specific pressure uniformity. Stuck pixels from backlight pressure sometimes resolve on their own when the panel cools.
For guidance on fixing stuck pixels on a laptop specifically, including pressure technique and software recovery options, the how to fix stuck pixels guide covers the step-by-step process. For dead pixel issues on MacBook Pro models specifically, the dead pixel MacBook Pro guide covers the known flex cable failure pattern and repair options.
Does a Stuck Pixel Spread?
No. A stuck or dead pixel does not spread to neighboring pixels under normal circumstances.
Each pixel has its own transistor and its own liquid crystal cell. A transistor failure in one pixel does not affect the transistors adjacent to it. The failure mechanism is not contagious. Neighboring pixels each operate independently.
The exception is physical damage. If a crack propagates through the display panel, additional pixels along the crack path will fail as the damage extends. If sustained pressure is applied to a region of the panel, multiple pixels in that region may fail over time as long as the pressure continues. But a single transistor failure or stuck liquid crystal cell, under normal use conditions with no ongoing physical stress, remains isolated.
The developer tools section has the dead pixel test and stuck pixel fixer available alongside other screen diagnostic utilities. If the defective pixel count is increasing over days, document the location and count and check your warranty coverage before the service window closes.
