How to increase QT apps font size?

QT apps on my setup have incredibly small fonts, tried this but could not make it work


I had this issue with QT apps like Strawberry, Texstudio, Octave, OBS-Studio etc.

What worked for me, for OBS-Studio, for example, was to edit the .desktop file located
at /usr/share/applications/com.obsproject.Studio.desktop.

I replaced the line Exec=obs with:

Exec=env QT_SCALE_FACTOR=1.25 obs

This seemed to be good enough on my 4k monitor - 1.5 might be a little better. I did this for a number of QT applications and it worked. I didn’t want to do it globally since some of my QT apps were scaling correctly already. I did need to log out/in for the change to take place. Hope this helps!


Why didn’t you try to use it as environment variable?

I thought he explained why he did not.

Oh sorry, thanks it worked in my case too

You can add export QT_SCALE_FACTOR=1.25 to your .bashrc file if you want the change to be global. I am using a 4k screen with display-scaling set to 100% and font-scaling set to 1.25.

Some QT apps, like KeePassXC respected the new font scaling, while the others I mentioned did not. So when I made the change globally, KeePassXC ended up getting scaled twice and was too big. So that is why I went for the .desktop files for particular QT apps. Hope that clears things up.