How to Change Font Size in Grub Menu
Guide Overview
The purpose of this guide is to teach you how to change the font size in Grub.
As our screens default to higher resolution, the font size for Grub appears smaller.
Older users are increasingly switching to Linux. Many may have vision issues.
Or, just like myself, some people may prefer big print on their terminal.
NOTE: If you have issues with Grub not working properly, this is not the solution. Please refer to the tutorial on Repairing or Replacing Grub.
Tools Needed
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A functioning Linux system with Grub installed and working.
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A Terminal Text Editor. For the purpose of instruction I am using Nano.
Instructions
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Step 1 – Find which video resolutions your BIOS can display.
The video used by Grub is not the same as the video used by your operating system. Grub uses the BIOS video.
The first thing we have to do is determine what video resolutions your BIOS supports.
To find out which resolutions are supported, you have to access the Grub command line.
This is done by interrupting the boot menu when you first start your computer.
While the Grub menu is being displayed, and before the timer reaches 0, press the letter "c".
You will get the grub prompt, which should look like this:
grub>
Type the following command, and hit enter:
videoinfo
Your should now see a list of screen resolutions supported by your BIOS.
Make a note of what resolutions are supported.
Use the escape key to return to the Grub menu, then boot you computer, as per normal.
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Step 2 – Examine and create a backup of your current Grub file.
Now have a look at your Grub file. From your Desktop, press and hold the Control and Alternate Keys, then press the T key.
This will open a terminal window on your desktop.
"ctl+alt+t"
Enter the following command:
cat /etc/default/grub
The cat command, short for “concatenate“, will print the grub file to the terminal screen.
You can scroll back and forth through the file by using the shift key and the page up and page down keys.
“shift+pgup” or “shift+pgdn”
Your grub file is a list of specific instructions you give to grub when you update it.
The grub file is NOT the grub configuration file. The grub.cfg file is located in the boot directory. DO NOT modify your grub.cfg file. The Grub software will do that for you.
Any line with the # symbol is ignored by the update-grub command.
There is a line there that directs us to an info file on our system, that gives more detailed instructions.
You may want to read it. It contains detailed instructions on what we are going to do.
To read the file, just enter the command as it appears:
info -f grub -n 'Simple configuration'
You can also find the complete grub manual on line at:
https://www.gnu.org/software/grub/manual/grub/grub.html
Right now, you are just going to follow the simple instructions, found in the grub file, it's self.
The particular paragraph the we are interested in is about 2/3rds the way down.
This is what it should say:
# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command `vbeinfo'
#GRUB_GFXMODE=640x480
Note that the GFXMODE line is commented out by the # symbol.
Most BIOS’s will support 640x480 VGA. However, this may be a little too big.
1024x768 or 800x600 may be better options.
Make a backup of your current Grub file.
Enter the following command:
sudo cp etc/default/grub etc/default/grub.bak
The Super User (sudo) command is required, because ordinary users cannot make changes to the system. It will ask you for your password.
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Step 3 – Edit your Grub file to set the video resolution used by Grub.
Open the Grub file using your text editor.
Enter the command:
sudo nano etc/default/grub
Scroll down until you reach the blank line under #GRUB_GFXMODE=640x480.
Add the following line to your Grub file. Substitute the 1024x768 for the resolution you wish to use.
GRUB_GFXMODE=1024x768
NOTE: The command is in UPPER CASE, and the instruction is in lower case
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Make sure you place a carriage return at the end of the line, by hitting the enter key. This will leave a blank line under the GFXMODE entry.
Use the Control key and X key to exit Nano.
“clt+x”
Nano will ask you if you wish to save your changes, answer with Y.
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Step 4 – Update Grub and reboot the computer.
You must now update Grub, so it will incorporate the change you have made into the Grub Menu.
Enter the “update-grub” command using sudo:
sudo update-grub
Once Grub has been updated, simply exit the terminal, and reboot your computer.
If you wish to have smaller text, redo the instructions above, using a higher resolution.
If you wish to have larger text, use a lower resolution.
Cheers!
Naught