Dead pixel test
Fill the screen with solid colours to spot dead and stuck pixels.
- 100% free
- No sign-up
- Runs in your browser
How to test for dead pixels
Start the test and look over the whole screen on each colour. A pixel that stays one colour while everything around it changes is faulty. You can also jump straight to one colour.
- Dead pixel
- Always black. Easiest to see on white.
- Stuck pixel
- Stuck on red, green or blue. Easiest to see on black.
- Hot pixel
- Always white. Easiest to see on black.
Stuck pixel fixer
A square flashes red, green, blue, white and black very fast. Drag it over a stuck pixel (or move it with the arrow keys) and leave it for 10 to 20 minutes. It sometimes frees a stuck pixel; it can’t fix a dead one.
Photosensitivity warning
The fixer flashes rapidly. Don’t use it, or look at it, if you or anyone nearby has photosensitive epilepsy or gets unwell from flashing lights. Look away while it runs.
Next: What is my screen resolution · Webcam test · Keyboard tester
Report a problem with this tool
How to use Dead pixel test
Start full screen
Wipe your screen, then press Start. It fills with one colour at a time.
Check each colour
Look over the whole screen. Click or press → for the next colour, ← to go back and Esc to exit.
Fix stuck pixels
Found a coloured dot that won’t change? Try the stuck pixel fixer over it for 10 to 20 minutes.
Why use Utils365
Every kind of fault
Black shows hot and stuck pixels, white shows dead ones, and red, green and blue show sub-pixels that are stuck.
Any screen
Monitors, laptops, TVs with a browser, tablets and phones: if it shows a web page, you can test it.
Stuck pixel fixer
A flashing square you can drag over a stuck pixel, with a clear photosensitivity warning before it starts.
Frequently asked questions
How do I check for dead pixels?
Clean the screen, start the full-screen test and look over every colour from about 30 cm away. A dot that stays one colour while the rest changes is a faulty pixel.
What is the difference between a dead and a stuck pixel?
A dead pixel is always black and shows up on white. A stuck pixel is stuck on red, green or blue and shows up on black or on other colours. A hot pixel is always white.
Can a stuck pixel be fixed?
Sometimes. Running the flashing fixer over it for 10 to 20 minutes can free it, though it doesn’t always work. A truly dead pixel can’t be fixed by software.
How many dead pixels are acceptable?
It depends on the maker. Most monitors are sold under ISO 9241-307 class II, which allows a few faulty pixels per million before a return; class I and some brands’ zero dead pixel guarantees allow none. Check your warranty.
Is the stuck pixel fixer safe?
It flashes rapidly, so don’t use it if you or anyone nearby is sensitive to flashing light. For the screen itself it is harmless; look away while it runs.
Should I test a new monitor?
Yes, as soon as it arrives. Many shops only accept a return for dead pixels within a short window, often 14 to 30 days.