Dead Pixel Test and Stuck Pixel Fixer
Fill your screen with solid colours one at a time. Dead pixels show as dark dots, stuck pixels as bright ones, and the fixer can help revive stuck ones.
Stuck pixel fixer
The fixer flashes rapidly changing colors. Do not use it, or look at it, if you have photosensitive epilepsy or are sensitive to flashing lights. Look away while it runs.
Drag the box over the stuck pixel, then let it run for 10 to 20 minutes.
What you are looking for
- Dead pixel
- Black on every color
- Stuck pixel
- One fixed color on all
- Hot pixel
- White on black
- Dust
- Moves or wipes off
A modern monitor has millions of pixels, each made of red, green and blue subpixels. It only takes one to fail for a tiny dot to sit in the same place forever, usually right where you look most. The good news is that finding one takes less than a minute, and some faulty pixels can be revived. This dead pixel test fills your screen with eight solid colors so defects stand out, and includes a stuck pixel fixer that flashes rapidly changing colors over the affected area.
It works on monitors, laptops, phones, tablets and TVs, and it is the first thing worth doing with any new or second hand screen while you can still return it.
How to check for dead pixels
- Clean the screen gently with a microfiber cloth so dust is not mistaken for a pixel fault.
- Press Fullscreen test. The cursor and label hide after a moment so nothing blocks your view.
- Look slowly across the whole screen, section by section. Get close enough to see individual pixels.
- Click, tap or use the arrow keys to move through black, white, red, green, blue, cyan, magenta and yellow. Or turn on Auto cycle and just watch.
- Note the position and behaviour of anything you find, then press Escape to exit.
Dead, stuck or hot: identifying the fault
Dead pixels
A dead pixel stays black on every color, most visible on white. The transistor that controls it has failed, so no light gets through. Dead pixels almost never recover.
Stuck pixels
A stuck pixel shows one fixed color, often red, green or blue, regardless of what should be displayed. One or more subpixels is stuck open. Stuck pixels are the ones that sometimes respond to the fixer.
Hot pixels
A hot pixel is permanently lit, showing white or bright color on a black screen. It is a stuck pixel with all subpixels open.
Dust and debris
A dark spot that shifts slightly when you change your viewing angle, or disappears when you wipe the screen, is on the surface or between the layers of the panel rather than a pixel fault.
| What you see | Likely fault | Fixable? |
|---|---|---|
| Black on white and colors | Dead pixel | Rarely |
| Same color on every background | Stuck pixel | Often worth trying |
| Bright dot on black | Hot pixel | Sometimes |
| Dot that moves or wipes off | Dust | Yes, clean it |
How the stuck pixel fixer works
The fixer paints a small grid of full-intensity colors that change on every frame your display draws, so a 60 Hz screen cycles sixty times a second and a 144 Hz screen even faster. The idea is to drive the stuck subpixel on and off repeatedly until the liquid crystal starts responding normally again. It does not work on every pixel, but it is harmless to try and often succeeds within twenty minutes on recently stuck pixels.
Using the fixer safely
The fixer produces rapidly flashing light. Do not use it or look at it if you have photosensitive epilepsy or are sensitive to flashing images. Read the warning, tick the confirmation box, and look away while it runs.
- Find the stuck pixel in the color test and note roughly where it is.
- Choose a flash area size. A small box is less distracting, the whole test area is easiest if the pixel is hard to locate.
- Start the fixer, drag the box over the pixel, and go fullscreen if the pixel is outside the preview.
- Leave it running for 10 to 20 minutes, then stop and check the pixel on each color again.
- Repeat a few times if the pixel is improving. The fixer stops automatically if you switch tabs.
What to do if you find a faulty pixel
- Check the warranty policy. Many manufacturers publish a pixel policy that sets how many defects are needed before they replace a panel. Some offer zero dead pixel guarantees on premium models.
- Act within the return window. Retailers are usually more flexible than manufacturers in the first two to four weeks.
- Try the fixer first for stuck pixels. It costs nothing but time.
- Avoid pressing the screen hard. The old trick of massaging a stuck pixel with a cloth can damage the panel and is not worth the risk on an expensive display.
Tips for a thorough pixel check
- Test in a dim room. Small bright defects are much easier to spot.
- Pay extra attention to white and black, which catch the most common faults.
- Work in a grid pattern across the screen so you do not skip areas.
- Check the edges and corners, which are easy to overlook.
- Recheck after a few days of use. Some faults only appear once a panel has been powered for a while.
Pixel faults are only one kind of panel defect. The monitor test checks uniformity, backlight bleed, banding and gamma, and the refresh rate test confirms the panel is running at its advertised speed. If you were checking a laptop, finish with the webcam test to make sure the built-in camera works too, and if the new screen is for gaming, see how quickly you respond on it with the reaction time test.
Frequently asked questions
How do I know if I have a dead pixel?
Fill the screen with white, then black, then each primary color. A dot that stays black on every color is a dead pixel. A dot that shows the same color on every background is stuck.
Can a dead pixel fix itself?
Truly dead pixels rarely recover. Stuck pixels sometimes clear on their own or respond to a stuck pixel fixer that flashes colors over them.
Is the stuck pixel fixer safe for my monitor?
Yes. It only displays normal colors, just very quickly. It is not safe for people with photosensitive epilepsy, so read the warning before using it.
How long should I run the pixel fixer?
Start with 10 to 20 minutes, then check the pixel. Repeat a few times if it is improving. Pixels that show no change after an hour or two are unlikely to respond.
Is one dead pixel a reason to return a monitor?
It depends on the retailer and manufacturer policy. Many accept returns for any defect within the first few weeks, so test early.
What is the difference between a dead and a stuck pixel?
A dead pixel stays black on every colour. A stuck pixel shows one colour, such as red or green, all the time and can sometimes be revived.
How many dead pixels are acceptable?
It depends on the manufacturer's pixel policy. Many brands replace a panel only above a certain number, while premium lines often accept one bright pixel.
Can a dead pixel spread?
Dead pixels usually stay as they are. A growing number of dead pixels suggests a failing panel.
Should I press on a stuck pixel?
Gentle pressure with a soft cloth sometimes works, but it can damage the panel. Try the pixel fixer first.
Related tools
Pixels are clean. Check the rest of the panel.
Gradients, black levels, uniformity and gamma reveal flaws a single color never will. Seventeen patterns, one click away.