How can I set the default font size for all Qt5 apps?
QT_DEVICE_PIXEL_RATIO
is deprecated since 5.4; instead, use QT_SCALE_FACTOR
. I use it, setting it to 1.5, with good results (e.g., VirtualBox 5.1)
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.
QT automatically scales the font based on the screen's DPI:
The traditional approach to supporting high DPI has been one where Qt scaled fonts automatically [...]
I had the problem that my screen has 166 dpi, but the font sizes chosen by Qt were much too large. Luckily, there is a way to tell Qt to assume a smaller value by setting QT_FONT_DPI
. For me, 128 is nice.
(I'm using cinnamon as desktop environment, and it pushes the configured font sizes for Gtk 1:1 to Qt, which is what brings this issue)