How to run a dead pixel test
- Clean the screen. Wipe it with a dry microfiber cloth. Dust and smudges are easy to mistake for dead pixels.
- Start the test. Press Start Test. The page goes fullscreen and every control fades away after a couple of seconds so nothing covers your pixels.
- Cycle through the colors. Click, tap, swipe or press → / Space to step through black, white, red, green, blue, 50% gray and more. Look at the whole panel from a normal distance, then up close.
- Note anything that doesn't match. A dot that stays black on white is a dead pixel. A dot that stays red, green, blue or white on black is a stuck or hot pixel.
- Try stuck pixel repair. Press R during the test to drop the Stuck Pixel Reviver over the spot and let it flash for 10–20 minutes.
What the screen uniformity checker reveals
Dead pixels
Pixels that never light up. They show as black dots on the white, red, green and blue screens.
Stuck & hot pixels
Sub-pixels frozen on. A single red, green, blue or white dot stands out most on the black screen.
Backlight bleed
Light leaking in at the edges or corners of an LCD. Check the black screen in a dark room at medium brightness.
Uniformity & clouding
Patchy brightness, tinted areas, vignetting or “dirty screen effect”. The 50% gray screen shows these best.
Stuck pixel repair
A stuck pixel still receives power; one or more of its sub-pixels is simply frozen. Rapidly cycling colors over it can sometimes nudge it back into working order. The built-in Stuck Pixel Reviver draws a small box of fast-changing red, green and blue noise that you can drag over the defect, resize, and speed up or slow down.
It's worth running for 10–30 minutes. Results aren't guaranteed, and truly dead pixels can't be revived by software, but the method costs nothing and won't harm a healthy display.
Photosensitivity warning: the reviver flashes rapidly. Don't use it if you're sensitive to flashing lights, and look away while it runs.
IPS glow inspector: glow vs. backlight bleed
IPS glow is a silvery or amber sheen, usually in the corners, and it's a normal trait of IPS panels. Backlight bleed is light escaping through gaps in the panel assembly, and that's a defect. To tell them apart, open the black screen in a dim room and move your head: IPS glow shifts or fades as your viewing angle changes, while backlight bleed stays in the same place and shape.
OLED screens have neither, because each pixel makes its own light. On OLED, use the gray and solid color screens to look for tint shifts, banding and burn-in instead.
Frequently asked questions
How do I run a dead pixel test?
Clean your screen, press Start Test and step through the fullscreen colors with a click, tap, swipe or the arrow keys. Check each color from a normal distance and up close. A dot that stays dark on bright colors is a dead pixel; a colored or white dot on black is a stuck pixel.
What is the difference between a dead pixel and a stuck pixel?
A dead pixel gets no power and stays black on every color. A stuck pixel has one or more sub-pixels frozen on, so it shows as a bright red, green, blue or white dot. Stuck pixels can sometimes be repaired; dead pixels usually cannot.
Can stuck pixel repair really fix my screen?
Sometimes. Flashing rapid colors over a stuck pixel with the Stuck Pixel Reviver for 10 to 30 minutes fixes some stuck sub-pixels, especially recent ones. It will not revive a dead pixel. If the defect remains and your display is under warranty, contact the manufacturer or seller.
Is the Stuck Pixel Reviver safe to use?
It will not harm a healthy display. Because it flashes very quickly, do not use it if you are sensitive to flashing lights, and look away while it runs. On OLED screens, keep sessions short and avoid leaving any static image on screen for hours.
How can I tell IPS glow from backlight bleed?
Show the black screen in a dim room and move your head. IPS glow shifts or fades as your viewing angle changes and is normal for IPS panels. Backlight bleed stays fixed at the edges or corners regardless of angle and is a panel defect.
What does a screen uniformity checker show?
Solid 50% gray, white and black screens reveal uneven brightness, tinted areas, dark corners, clouding and the dirty screen effect. Turn off night light, adaptive brightness and HDR first so the display shows the colors as intended.
Does this dead pixel test work on phones, tablets, TVs and OLED screens?
Yes. It runs in any modern browser on Windows, macOS, Linux, Android, iOS and smart TVs, and supports mouse, keyboard and touch. On iPhone the browser toolbar may stay visible because iOS limits fullscreen for web pages.
How many dead pixels are acceptable?
It depends on the manufacturer. Many follow the pixel fault classes in ISO 9241-307, which allow a small number of defects per million pixels, while some brands offer zero bright dot guarantees. Test new screens within the return window and check the warranty policy.
How accurate are the display details?
Resolution, device pixel ratio and color depth come straight from your browser. Refresh rate is estimated by timing animation frames, so battery saver modes, variable refresh rate or a busy computer can make it read lower than the panel maximum.
Is any data collected?
No. Dead Pixel Testing runs entirely in your browser with no accounts, cookies, analytics or uploads. Your custom color and reviver settings are saved only in your own browser.