How can I change the resolution of the GRUB menu?

Solution 1:

the default look of my grub menu when the some of the content in /etc/default/grub file is

GRUB_DEFAULT=0
GRUB_TIMEOUT_STYLE=hidden
GRUB_TIMEOUT=10
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
GRUB_CMDLINE_LINUX=""
#GRUB_GFXMODE=640X480

When i edited the file and changed some of the content in /etc/default/grub like below

GRUB_DEFAULT=0
GRUB_TIMEOUT_STYLE=hidden
GRUB_TIMEOUT=10
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
GRUB_CMDLINE_LINUX=""
GRUB_GFXMODE=640X480

and run sudo update-grub it looks like this

when content is like this

GRUB_DEFAULT=0
GRUB_TIMEOUT_STYLE=hidden
GRUB_TIMEOUT=10
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
GRUB_CMDLINE_LINUX=""
GRUB_GFXMODE=960X600

It looks like this after running sudo update-grub

The value 960x600 i choose from below

pratap@i7-6550U:~$ xrandr
Screen 0: minimum 320 x 200, current 1366 x 768, maximum 8192 x 8192
eDP-1 connected primary 1366x768+0+0 (normal left inverted right x axis y axis) 344mm x 194mm
   1366x768      60.00*+
   1360x768      59.80    59.96  
   1280x720      60.00    59.99    59.86    59.74  
   1024x768      60.04    60.00  
   960x720       60.00  
   928x696       60.05  
   896x672       60.01  
   1024x576      59.95    59.96    59.90    59.82  
   960x600       59.93    60.00  
   960x540       59.96    59.99    59.63    59.82  
   800x600       60.00    60.32    56.25  
   840x525       60.01    59.88  
   864x486       59.92    59.57  
   800x512       60.17  
   700x525       59.98  
   800x450       59.95    59.82  
   640x512       60.02  
   720x450       59.89  
   700x450       59.96    59.88  
   640x480       60.00    59.94  
   720x405       59.51    58.99  
   684x384       59.88    59.85  
   680x384       59.80    59.96  
   640x400       59.88    59.98  
   576x432       60.06  
   640x360       59.86    59.83    59.84    59.32  
   512x384       60.00  
   512x288       60.00    59.92  
   480x270       59.63    59.82  
   400x300       60.32    56.34  
   432x243       59.92    59.57  
   320x240       60.05  
   360x202       59.51    59.13  
   320x180       59.84    59.32  
HDMI-1 disconnected (normal left inverted right x axis y axis)
pratap@i7-6550U:~$ 

Solution 2:

You can use 1920x1080 screen size but you will want to generate a larger font. Although the following GIF uses grub themes for additional graphics, generating larger 24 or 36 point fonts is the same for regular grub.

Make Grub fonts

Even if you are just using regular grub, if you want a different font you must use grub-mkfont program first. The same holds true for Grub Customizer used by OP and Grub Themes used in first section of this answer.

Here are the fonts I have made for grub to use:

$ ll /usr/share/grub/themes/Tuxkiller2/*.pf2
-rwxrwx--- 1 root root 176923 Jun  9 16:41 /usr/share/grub/themes/Tuxkiller2/dejavu_14.pf2*
-rwxrwx--- 1 root root  20041 Jun  9 16:41 /usr/share/grub/themes/Tuxkiller2/droidlogo_bold_17.pf2*
-rwxrwx--- 1 root root  23339 Jun  9 16:41 /usr/share/grub/themes/Tuxkiller2/droidlogo_bold_20.pf2*
-rwxrwx--- 1 root root  31498 Jun  9 16:41 /usr/share/grub/themes/Tuxkiller2/droidlogo_bold_26.pf2*
-rwxrwx--- 1 root root  15244 Jun  9 16:41 /usr/share/grub/themes/Tuxkiller2/droidlogo_regular_12.pf2*
-rwxrwx--- 1 root root  19148 Jun  9 16:41 /usr/share/grub/themes/Tuxkiller2/droidlogo_regular_17.pf2*
-rwxrwx--- 1 root root 113623 Jul 11 17:05 /usr/share/grub/themes/Tuxkiller2/ubuntu_bold_italic_36.pf2*
-rwxrwx--- 1 root root  45391 Jul 11 17:08 /usr/share/grub/themes/Tuxkiller2/ubuntu_light_20.pf2*
-rwxrwx--- 1 root root  41020 Jul 11 17:16 /usr/share/grub/themes/Tuxkiller2/ubuntu_regular_18.pf2*
-rwxrwx--- 1 root root  46423 Jul 11 17:16 /usr/share/grub/themes/Tuxkiller2/ubuntu_regular_20.pf2*
-rwxrwx--- 1 root root  68602 Jul 11 16:59 /usr/share/grub/themes/Tuxkiller2/ubuntu_regular_28.pf2*

To create a font use the grub-mkfont program like this guide outlines: Increase Font in GRUB for High DPI Screens:

sudo grub-mkfont --output=/boot/grub/fonts/DejaVuSansMono24.pf2 \
  --size=24 /usr/share/fonts/truetype/dejavu/DejaVuSansMono.ttf

Then in your /etc/default/grub configuration file tell it to use the new .pf2 font file:

# More readable font on high dpi screen, generated with
# sudo grub-mkfont --output=/boot/grub/fonts/DejaVuSansMono24.pf2 \
#    --size=24 /usr/share/fonts/truetype/dejavu/DejaVuSansMono.ttf
GRUB_FONT=/boot/grub/fonts/DejaVuSansMono24.pf2

Finally run:

sudo update-grub