Guide · Dead Pixel Test
How to check your screen for dead pixels
Updated · 7 min read
A single wrong-coloured dot is easy to miss on a busy desktop, and impossible to ignore on a white page. The best time to check is when you first unbox a monitor, laptop or phone, because that is when returns are simplest. This guide shows how to check for dead pixels and how to tell them from other screen defects.
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The dead pixel test fills your screen with solid colours so defects stand out.
- Clean the screen first, because dust and fingerprints look like pixel faults.
- Open the test and press Start fullscreen test.
- Click, tap or use the arrow keys to move through black, white, red, green and blue.
- Look at every part of the screen from a normal viewing distance, then up close.
- Press Escape to leave fullscreen.
Dead, stuck and hot pixels
A dead pixel does not light at all, so it looks black on every colour except a black screen. A stuck pixel is stuck on one colour, such as red, and shows up against other backgrounds. A hot pixel is permanently on and appears white or bright on a black screen. A screen pixel is made of three sub-pixels, red, green and blue, which is why a fault can show as a single colour rather than black.
It is also worth separating pixel faults from other defects, such as backlight bleed, which glows at the edges on a dark screen, and image retention, which fades after a while and is not a hardware fault.
What each colour reveals
Use a black screen to find stuck and hot pixels, since any lit dot is easy to see. Use white to find dead pixels, which appear as dark dots. Red, green and blue reveal faults in single sub-pixels. Cycle all of them slowly, and look at the corners and edges, which many people skip.
What to do if you find one
Your next step depends on the type and on how new the screen is.
- If the screen is new, take a photo and contact the seller or manufacturer immediately.
- Check the manufacturer’s pixel policy. Many allow a small number of faulty pixels before they replace a panel, and some premium lines promise zero.
- If the pixel is stuck rather than dead, try the stuck pixel fixer and read the fix guide.
- A dead pixel on its own is permanent, so a replacement or a refund is the realistic outcome.
How to test every device
The same test works on a phone, a tablet, a laptop and a TV. On OLED phones, a dead pixel is rarer but burn-in and uneven tint can appear, so look at the whole screen under white and grey. If you plan to measure something on the screen afterwards, try the screen ruler.
FAQ
Common questions
How do I check my screen for dead pixels?
Open the dead pixel test, go fullscreen and cycle through solid colours. Any dot that does not match its surroundings is a faulty pixel.
What is the difference between a dead pixel and a stuck pixel?
A dead pixel is black on every colour. A stuck pixel stays on one colour, such as red, green or blue.
Can a dead pixel spread?
A dead pixel does not spread by itself. If more appear nearby over time, the panel may be failing and should be inspected.
Will the manufacturer replace a screen with one dead pixel?
It depends on the policy and the model. Many require several faulty pixels or a zero-defect guarantee, so check before you buy and keep the receipt.