Is there a way to use fractional scaling below 100%

Question

Many laptops in the educational market still have 1366x768 screens. A lot of programs and websites blindly assume a 1920x1080 screen, and leave important UI elements outside the screen (mostly dialog boxes that are improperly centered or sized). For these laptops, a scaling set to 75% would be sufficient to allow these apps and websites function properly.

Is there a way to enable sub 100% scaling for individual screens in Gnome?

The approach mentioned in AskUbuntu's Gnome fractional scaling below 100% works, but poorly:

• The .config/monitors.xml is not created by default - you need to create it by changing your screen resolution to, say, 1280x720.
• With the file, you can edit the scale tag to a value lower than 1. ".75" doesn't work and is interpreted as "1". You can define it as ".5", but it overshoots the sweet spot.
• With scale set to 50% (.5) Firefox works properly, but Chrome pops up at .25 scale, tiny and unreadable.
• If resolution is set to the same as the panel (1366x768), scale is ignored and always interpreted as 100%.

• Stephen Kitt: This doesn’t address your question, but it helps dealing with windows that are too large for the screen — in GNOME, holding down the Super key (the Windows key usually) and clicking anywhere in a window allows it to be moved around, without having to use the title bar.
• phuclv: @StephenKitt it's the Alt key, not Super key although you can change it
• phuclv: not an answer but you can set a bigger virtual resolution and pan it to move with the mouse, something like xrandr --output eDP-1 --mode 1366x768 --fb 1920x1080 --panning 1920x1080
• Stephen Kitt: @phuclv that answer explains how to restore the old use of Alt; on GNOME 3 it really is Super.

Answer 1

You won't, at least in your case Gnome DE, no matter X11 or Wayland. Your best bet is scaling font of text only in Gnome Tweaks. If you don't wanna install one more app, just run single command:

gsettings set org.gnome.desktop.interface text-scaling-factor 0.8

• rbanffy: Thanks, @Lilith. I think this will affect all screens, not only the built-in one.

Answer 2

With xrandr, you can use the --scale-from option to set the application-visible resolution independent of the real screen resolution, but this requires chipset support.