Best 3 Dead Pixel Test Tools Compared

A new monitor arrives and you have perhaps two weeks to decide whether it is perfect. Normal use will never tell you — a dead pixel is invisible against a photo or a text document, and completely obvious against a full screen of solid red.

That is the whole test: fill the screen with one colour at a time and look. It is simple enough that dozens of sites do it, and they differ in how many colours they cycle, whether they include a stuck pixel fixer, and whether they check the other panel faults worth catching in the same window.

How to judge a pixel test

How many colours? Black, white, red, green and blue is the minimum. Grey and gradient screens catch dim and subpixel faults the primaries miss.

Does it distinguish the fault types? Dead is dark on white, stuck is a fixed colour, hot is bright on black. Only stuck pixels are worth trying to fix, so the distinction decides what you do next.

Is there a fixer? Rapid colour cycling over a stuck pixel sometimes unsticks it. It is not magic, it costs nothing, and it does not work on dead pixels at all.

Does it check anything else? Backlight bleed and IPS glow are the other faults worth spotting inside a return window.

The comparison

Facts checked August 2026; tools change. Table covers only the 3 alternatives — our tool gets its own section below.

ScreenDetect Pixel Test

The most educational, and the most useful if you are about to make a warranty claim. It fills the screen with black, white, red, green and blue — five on phones, up to ten on desktop including grey, gradient and pattern screens — and explains how to classify what you find: dead pixels as dark dots on bright backgrounds, stuck pixels as fixed red, green or blue dots, hot pixels as bright white dots on black.

That classification matters because manufacturers’ warranty policies often distinguish between them, and because only stuck pixels respond to a fixer. It runs entirely in the browser with no app, account or download, free.

HardwareTest.org

The broadest check. Beyond dead and stuck pixels it covers backlight bleed and IPS glow — light leaking at the edges of a dark screen, and the off-angle sheen typical of IPS panels — which are both worth assessing in the same sitting, since they are also return-window issues and equally invisible during normal use.

It includes a stuck pixel fixer that flashes colours over the affected area for 10 to 20 minutes, states that testing runs locally in your browser with no data collection, and needs no account. If you are inspecting a new panel properly rather than checking one suspicious dot, this covers the most ground.

DeadPixel.tools

The most thorough on colour coverage: eight colours in the full test — black, white and the six primaries — which catches subpixel faults that a five-colour cycle can miss. It also has a dedicated stuck pixel fixer using rapid colour cycling, recommended to run for 10 to 30 minutes, with the FAQ suggesting 20 to 30 for the best chance.

No sign-up, free, works on monitors, laptops, phones and tablets. It is the most focused of the three — pixels and nothing else — which is either exactly right or a reason to use HardwareTest instead, depending on whether the panel is new.

Dead Pixel Test

Ours cycles full-screen solid colours to reveal dead, stuck and dim pixels on an LCD or OLED panel, framed explicitly around checking before a warranty window closes — which is the only moment when any of this is actionable.

What it does not do: include a stuck pixel fixer, or test backlight bleed and IPS glow. If you find a stuck pixel, DeadPixel.tools’ fixer is worth half an hour before you start a return; if the panel is new, HardwareTest’s wider checks are worth running in the same session. Dim pixels are the ones most tests skip, and they are the hardest to spot without a deliberate comparison — defective pixel covers how manufacturers classify them, which is what your warranty claim will be judged against.

Which one to pick

• A brand new panel, checked properly — HardwareTest.org, for bleed and glow too.
• A stuck pixel you want to try fixing — DeadPixel.tools’ fixer.
• Working out which type of fault you have — ScreenDetect’s classification.
• A quick colour cycle before the return window closes — the tool below.

How to do it with Dead Pixel Test

1. Clean the screen first — a speck of dust looks exactly like a dead pixel.
2. Open the Dead Pixel Test in full screen, in a dim room.
3. Move through each colour slowly, scanning the whole panel rather than the centre.
4. Photograph anything you find, with the colour on screen. That photo is your warranty evidence.

The walkthrough is in how to test a screen for dead and stuck pixels. Other tools are in the tools directory.

You might also need

The Screen Resolution Detector confirms the panel is actually running at its native resolution — a surprisingly common problem that makes everything look slightly soft.

Frequently asked questions

Is there a free dead pixel test that doesn’t need an app?

All four here run in a browser tab with no download and no account. They differ in how many colours they cycle and whether they add a fixer or wider panel checks.

What is the difference between a dead and a stuck pixel?

A dead pixel receives no power and stays black. A stuck pixel is permanently showing one colour — red, green or blue — because a subpixel is jammed on. Stuck pixels sometimes recover with a fixer; dead ones never do.

Will a manufacturer replace a screen with one dead pixel?

Often not. Most have a policy specifying a minimum number of defective pixels, sometimes varying by where on the screen they fall. Check the specific policy before starting a claim, and test early — the window is shorter than the warranty.

Final thought

Test the day it arrives, not the day you notice something. Every one of these tools takes two minutes, and the only thing that expires is your ability to do anything about what you find.

Try the free Dead Pixel Test