How to set the default font size for all Qt5 apps

configurationfontsqt

I run Gnome, which has pretty good support for my HiDPI screen. However, when I run QT apps I can't seem to find a way to scale the fonts. Is there a way to do this without installing a full version of KDE?

Best Answer

Updated:

Since Qt 5.6, Qt 5 applications can be instructed to honor screen DPI by setting the QT_AUTO_SCREEN_SCALE_FACTOR environment variable. If automatic detection of DPI does not produce the desired effect, scaling can be set manually per-screen (QT_SCREEN_SCALE_FACTORS) or globally (QT_SCALE_FACTOR). You can also use QT_FONT_DPI to adjust scaling of text.

Original:

You can try this recipe from the archwiki

Qt5 applications can often be run at higher dpi by setting the QT_DEVICE_PIXEL_RATIO environment variable. Note that the variable has to be set to a whole integer, so setting it to 1.5 will not work.

This can for instance be enabled by creating a file /etc/profile.d/qt-hidpi.sh

export QT_DEVICE_PIXEL_RATIO=2

And set the executable bit on it.