Dead Pixel and Stuck Pixel Test
Fill your screen with solid colors to spot dead pixels, stuck pixels, and light leaks. Do this as soon as you receive a monitor, laptop, or phone, while you can still return it.
- Full screen
- Solid colors
- Stuck-pixel fixer
- No install
100% private — Everything is processed directly in your browser: your files, voice, and image are never sent to Chatzam's servers.
How to detect a dead pixel?
-
Go full screen
Clean your screen so you don't mistake a speck of dust for a pixel, then start the test: the whole screen turns a solid color.
-
Cycle through the colors
Click or use the arrow keys to move through black, white, red, green, blue, and gray.
-
Inspect the screen
Scan the screen closely: a spot that doesn't change with the color is a dead or stuck pixel.
Everything you need to check your screen's panel
Solid colors
Black, white, red, green, blue, gray… each color reveals a different type of defect.
Light leaks
On a black background, in a dark room, spot the bright halos along the edges (backlight bleeding).
Stuck-pixel fixer
A small square that flashes different colors, placed over the stuck pixel to try to unstick it.
Simple navigation
Switch colors with a click or the arrow keys, with nothing to install.
Dead pixel or stuck pixel: what's the difference?
A dead pixel no longer lights up: it stays black no matter what color is displayed, and shows up mainly on a white background. A stuck pixel is locked on one color (red, green, blue, or white) and stands out on a black background or against another color. It's the only one of the two that can sometimes be fixed. Light leaks, or backlight bleeding, are bright halos along the edges of LCD screens, visible on a black background in a dark room; OLED screens, which have no backlight, don't have this issue.
Fixing a stuck pixel: does it actually work?
The fixer tool rapidly flashes a small square of colors, which you place over the stuck pixel and let run for several minutes. This sometimes works on a stuck pixel, with no guarantee, and never on a dead pixel. Warning: these rapid flashes can trigger a seizure in people with photosensitive epilepsy. Don't stare at the screen while the fixer is running, and don't use this tool if this applies to you.
Test a screen as soon as you receive it, so you can still return it
Run this test as soon as you receive a monitor, laptop, or smartphone: if there's a defect, you're still within the return window (often 14 to 30 days for an online purchase, depending on your country and the retailer's policy). Many manufacturers actually tolerate a few defective pixels before accepting a warranty exchange, so a quick return is often simpler. Note down the pixels' location and take a photo. To check the rest of your hardware, also try our “Keyboard Test” and “Left-Right Audio Test”.
Frequently Asked Questions
How do I know if I have a dead pixel?
Display a full-screen white background, then a black one: a black dot on a white background is a dead pixel; a colored or white dot on a black background is a stuck pixel.
Can a dead pixel be fixed?
No, not with software: a dead pixel doesn't light up at all anymore. Only a stuck pixel can sometimes be unstuck with the fixer tool, with no guaranteed result.
Is the fixer tool dangerous?
Not for the screen, but its rapid flashing can trigger a seizure in people with photosensitive epilepsy. Don't stare at it, and avoid it if this applies to you.
How many dead pixels are acceptable?
Each manufacturer sets its own tolerance in its warranty policy: some replace the screen after a single defective pixel, others only after several. Check your brand's terms and, when in doubt, use your return window while it's still open.
What is backlight bleeding?
It's light leaking from the backlight, visible as bright halos along the edges of an LCD screen displaying black. A slight halo is common; very noticeable patches may be grounds for a return.