Tools

Dead pixel test

Fill the screen with solid colours to find dead and stuck pixels.

Loading…

Runs in this page in your browser; nothing is uploaded.

About this tool

Find dead and stuck pixels on a screen online. Use it to check a new monitor, laptop or phone while you can still return it, to inspect a second-hand device before you buy, or to take a closer look at a dot that never seems to change.

Nine solid colours are available: black, white, red, green, blue, yellow, cyan, magenta and grey. Show them full screen, where the pointer is hidden, and step through them one by one. Where full screen is not possible, such as Safari on iPhone, use the coloured area on the page. Everything runs in your browser; nothing is uploaded.

How to use it

Select “Start full-screen test”. The screen fills with the current colour, black at first.
Click, or press Space or the right or down arrow, for the next colour; the left and up arrows go back.
Look over the whole screen in each colour for dots that stay the same.
Press Esc to leave full screen. You can also select a colour button to show that colour in the area on the page.

Common questions

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

A dead pixel stays dark and is easiest to see on white and other bright colours. A stuck pixel stays lit and stands out most on black.

Why check so many colours?

Some faulty pixels show up only against certain colours. A pixel stuck on red, for example, is obvious on black, green or blue but disappears on red, so going through all nine makes it harder to miss one.

Why can’t I go full screen on my phone?

Some browsers, such as Safari on iPhone, do not let a page show an element full screen, so “Start full-screen test” is disabled. Use the coloured area on the page and switch colours with the buttons.

Local first