Dead Pixel Test
Fill your screen with solid colors one after another and look for tiny dots that do not match. It is the quickest way to check a new monitor, laptop or phone for dead or stuck pixels.
- Runs in your browser
- Only your score is shared, anonymously
- Free, no sign-up
Or start from a color:
In full screen: click / tap / → next color, ← previous, Esc exit.
Clean your screen first so dust is not mistaken for a pixel.
Did you find a bad pixel? Your anonymous answer builds the pixel map on this page.
How to check for dead pixels
- Wipe the screen with a dry microfiber cloth so specks of dust do not fool you.
- Press Start full-screen test. The whole screen turns black.
- Look slowly across the screen from about 30-50 cm away. Then click, tap or press the right arrow for the next color: white, red, green, blue, cyan, magenta, yellow and gray.
- On each color, look for a dot that is a different color from the rest. Note where it is and on which background it shows.
- Press Esc (or tap through all colors on a phone) to leave full screen.
What the results mean
A healthy screen shows every color perfectly evenly. If you find a dot, the background it shows on tells you what kind of fault it is:
| What you see | Type | Can it be fixed? |
|---|---|---|
| Black dot on white and on every color | Dead pixel | Rarely. The transistor gets no power. |
| Bright red, green or blue dot on black | Stuck pixel (one sub-pixel always on) | Often. Try the stuck pixel fixer. |
| White dot on black | Hot pixel (all sub-pixels on) | Sometimes, with the stuck pixel fixer. |
| Dot missing only on red, green or blue | Dead sub-pixel | Rarely. |
A dot that moves when you wipe the screen is dust. A cloudy patch rather than a sharp dot is backlight bleed or pressure damage, not a pixel fault.
How other people score on Testnook
Anonymous results from the last 30 days on this site, updated hourly. The top and bottom 1% are left out of the average, and results that fail our checks are not counted.
- Dead pixel test: no results yet, stats appear at 10.
Dead pixel test for monitors, laptops and phones
The same test works on any screen: an office monitor, a gaming monitor, a laptop, a TV through a browser, a tablet or a phone. On a phone, tap anywhere to change color; the page uses a full-window mode where the browser cannot go fully full screen. Turn screen brightness up to make faults easier to see, and on OLED phones look at the black screen closely, because a stuck sub-pixel glows clearly against true black.
Check a new device as soon as it arrives. Most shops and manufacturers only accept pixel complaints inside the return period, and many have a "pixel policy" that allows a few faulty pixels before they will swap the screen. A screenshot will not show the fault, so take a photo of the dot with your phone as evidence.
Common problems and fixes
I found a colored dot that is always on
That is a stuck pixel, and it can often be revived. Run our stuck pixel fixer over the spot for 10-20 minutes. Gently massaging the spot through a soft cloth while the screen is on can also help, but never press hard.
I found a black dot on every color
A truly dead pixel usually cannot be repaired at home. If the device is new, contact the seller or manufacturer and quote their dead pixel policy. Include a photo of the dot on the white screen.
Full screen does not work on my iPhone
iPhone Safari does not allow web pages to go fully full screen, so the test fills the browser window instead. Rotate to landscape and scroll so the address bar shrinks, or add the page to your home screen for a cleaner view.
Frequently asked questions
How do I check my screen for dead pixels?
What is the difference between a dead pixel and a stuck pixel?
Can dead pixels spread?
Is one dead pixel acceptable?
Does this dead pixel test work on phones?
Can a dead pixel test damage my screen?
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