Dead Pixel Test
Fill your screen with solid colors to spot dead pixels, stuck pixels and backlight bleed on any monitor, laptop or phone.
Open source on GitHubFull-screen color test
The screen fills with one solid color at a time. Look closely across the whole display for dots that don’t match.
Clean your screen first so dust isn’t mistaken for a dead pixel. On phones, tap to change color and use the Exit button.
Start from a color
Find dead pixels in three steps. Takes about a minute.
Go full screen
Start the test and the display fills with one color. Turn brightness up and clean the screen so dust isn’t mistaken for a fault.
Scan each color
Look slowly across the whole screen, including corners and edges, then press → for the next color. Each color reveals a different kind of fault.
Note what you find
Write down the position and which colors show the dot. A dot that is wrong on every color is dead; one that only shows on some is stuck.
Dead, stuck or something else? How to tell screen faults apart.
| Fault | How it looks | What it means |
|---|---|---|
| Dead pixel | Black on every color, most visible on white | Transistor failure. Permanent; usually a warranty case if you have more than the maker’s allowance. |
| Stuck pixel | Always red, green or blue, most visible on black | A subpixel stuck on. Sometimes recovers with time or gentle pressure through a cloth with the screen off. |
| Hot pixel | Always white, most visible on black | All subpixels stuck on. Same options as a stuck pixel. |
| Backlight bleed | Bright patches near edges on black or gray | Uneven panel pressure. Common on IPS panels at some level; severe bleed may qualify for a return. |
| Dust or debris | Dot that moves or wipes away | Not a pixel fault. Clean the screen with a microfiber cloth. |
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Frequently asked questions
How do I check for dead pixels?
Click “Start full-screen test”, then step through each color with a click or the arrow keys. Look across the entire screen for dots that don’t match the background. Press Esc to exit.
What is the difference between a dead pixel and a stuck pixel?
A dead pixel stays black because it gets no power. A stuck pixel stays lit in one color (red, green or blue) because a subpixel is stuck on. Stuck pixels sometimes recover; dead pixels usually don’t.
Can a stuck pixel be fixed?
Sometimes. Leaving the display off for a while, or gently massaging the spot through a soft cloth with the screen off, occasionally frees it. Avoid pressing hard, which can create more damage.
Does this work on phones and tablets?
Yes. Tap to change color. Some phone browsers, including Safari on iPhone, can’t go true full screen, so the test fills the browser window and shows an Exit button instead.
How many dead pixels are acceptable?
It depends on the manufacturer. Most publish a pixel policy that sets how many dead or stuck pixels a panel can have before it qualifies for replacement. Check yours before you contact support.