How do I scale i3 window manager for my HiDPI display?

Question

I have a Dell XPS 13 9343 2015 with a resolution of 3200x1800 pixels.

I am trying to use i3 windows manager on it but everything is tiny and hardly readable.

I managed to scale every applications (firefox, terminal, etc...) using .Xresources :

! Fonts {{{
Xft.antialias: true
Xft.hinting:   true
Xft.rgba:      rgb
Xft.hintstyle: hintfull
Xft.dpi:       220
! }}}

but i3 interface still does not scale...

---

I have understood that xrandr --dpi 220 may solve the problem, but I don't know how/where to use it.

Can somebody enlighten me on this issue ?

Answer 1

Since version 4.13 i3 reads DPI information from Xft.dpi (source). So, to set i3 to work with high DPI screens you'll probably need to modify two files.

Add this line to ~/.Xresources with your preferred value:

Xft.dpi: 120

Make sure the settings are loaded properly when X starts in your ~/.xinitrc (source):

xrdb -merge ~/.Xresources
exec i3

Note that it will affect other applications (e.g. your terminal) that read DPI settings from X resources.

Answer 2

You can run xrandr as any user running an X session. Xrandr is a command line program, so you run it in your terminal.

So you would run something like this in your user terminal

$ xrandr --dpi 220

Answer 3

If you only want to change the DPI within i3, you could put the command in your i3 config file with the line:

exec xrandr --dpi 220

Depending on your distro you will find the config file in different places but often under ~/.config/i3/config

Answer 4

Frankly on VirtualBox, I solved my I3 issue configuring resolution by a standard ubuntu/linux environment way , because the chosen answer in here didn't work for me when using VirtualBox ('xrandr --dpi 220') - my i3 session windows was just closed. So I used the following standard sequence of commands for configuring resolution:

cvt 3840 2160 60
// Output: -> Modeline "3840x2160_60.00"  712.75  3840 4160 4576 5312  2160 2163 2168 2237 -hsync +vsync

Using part of output (after word Modeline) as a parameter of a new command

xrandr --newmode "3840x2160_60.00"  3840x2160_60.00"  712.75  3840 4160 4576 5312  2160 2163 2168 2237 -hsync +vsync
xrandr --addmode VGA-1 3840x2160_60.00

// this last command activates the created resolution

xrandr -s 3840x2160

In order to preserve the configuration between user logging sessions, one has to put of course the following commands into a .bashrc init file.

Once configured, to get rid of 1 pixel scrollbars spaces, View->Scaled mode from menu is option. I also hat to configure my UltraHd display as a main display in Windows host.

My solution is a combination of two answers from the following link: Referrence: https://askubuntu.com/questions/377937/how-to-set-a-custom-resolution

Edit: Simplified appliance containg one one-liner

eval $(cvt 2220 1250 60 |sed 's/Modeline/xrandr --newmode /g'|sed -n '1!p')

as a proper result resolution screen size aspect ratio might be afterwards reevaluated/adjusted, therefore find out the created resolution by xrand command - appended in the end of output,

1) assign the resolution to a specific display -

xrandr --addmode VGA-1 "2224x1250_60.00"

2) output the desired resolution on the display

xrandr --output VGA-1 --mode "2224x1250_60.00"

Answer 5

Create the ~/.Xresources file with this content:

Xft.dpi: 96

Replace 96 with the DPI you'd like to set.

Answer 6

I had the top answer working for years, something changed in my most recent update on debian testing.

To get scaling for the i3 bar and other things within i3 itself: in ~/.config/i3/config I appended

exec xrandr --dpi 192

For my application windows: in ~/.profile I added

export GDK_SCALE=2

Answer 7

Since the edit in my question go removed (not sure why), here is how I fixed it :

I solved it by simply putting :

xrandr --dpi 220
exec i3

In my .xinitrc.