Dead Pixel Test

Find dead and stuck pixels on any monitor, laptop, TV or phone: the screen fills with solid black, white, red, green, blue and more, one colour at a time, so faulty pixels stand out. Includes an optional stuck-pixel fixer.

This tool runs entirely in your browser.

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How to use the Dead Pixel Test

1Clean the screen, then click “Start full-screen test”.
2Look over the whole screen for dots that don’t match the colour; click or press Space or → for the next colour, ← to go back.
3Press Esc to exit. If you found a coloured stuck pixel, you can try the optional fixer.

What is the Dead Pixel Test?

A dead pixel never lights up, so it shows as a black dot on white and bright colours. A stuck pixel has one or more sub-pixels stuck on, so it shows as a red, green, blue or white dot on black or on the other colours. Checking each colour in full screen makes both easy to see; a magnifying glass or your phone’s camera zoom helps on high-resolution screens.

Stuck pixels sometimes recover when flashed with rapidly changing colours for 10–20 minutes — that is what the optional fixer does (about 10 colour changes per second, with a running timer), after a photosensitivity warning. Dead pixels are a hardware fault and usually cannot be repaired; check the manufacturer’s pixel policy (often based on ISO 9241-307 classes), because many warranties replace a screen only above a certain number of faulty pixels.

Frequently asked questions

How do I test a new monitor for dead pixels?

Run this test within the return period, in a dim room, at the monitor’s native resolution. Look at each colour from normal viewing distance and then up close.

Is it a dead pixel or dust?

Dust usually looks blurry and moves when you wipe the screen; a dead or stuck pixel is a sharp dot that stays in the same place on every colour.

Does the test work on phones and TVs?

Yes — open the page in the device’s browser. Phones that don’t support full screen still show the colour across the whole visible page.

Is the Dead Pixel Test free and private?

Yes. The Dead Pixel Test is free, needs no account, and runs entirely in your browser. What you type is never sent to a server or stored.

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