I suspect there are few of hot pixels on my panel. As it is still under warranty and by the rules of my vendor I can replace a machine if panel has a 3 dead pixels on it, I'd like to check how many dead pixels there actually are. In Windows, there are plenty of simple applications that just fill the whole screen with different colors so hot/dead pixels are easily visible. Does something like this exists for Ubuntu?


open terminal and install:

sudo apt-get install screentest



right click on the screen to access the options for different test colors and patterns


This page just provides the white / black / red / green / blue screens to test your monitor: http://lcdtech.info/en/tests/dead.pixel.htm

  • Any reason to recommend this HTTP website over any similar web test? Webpages aren't typically saved for offline use and I feel that the answer is off-topic.
    – user598527
    Sep 29 '20 at 10:22

You could use GIMP Image Editor to make 4 images that are the same size as your desktop and color them red / green / blue / white.

Then open them in Image Viewer ( default picture viewer ).

Then dual click on the picture to get it full screen.

GIMP Image Editor is available from the Ubuntu Software Center

Following is a How-To for the visual learners.

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