Customizing Grub

GRUB's default look is purely functional. Installing a theme and tuning a couple of settings makes boot feel intentional instead of accidental, and along the way it's worth knowing how to regenerate the GRUB config correctly on both Ubuntu and Fedora, since the two differ.

Download a Theme

Sites like GNOME-Look.org host GRUB themes. Always check the theme's README first — many ship an install.sh that automates the rest.

Extract It

tar -xvf theme-file.tar.gz

A typical theme (e.g. Vimix) extracts to something like:

Vimix-4k/
├── install.sh
├── LICENSE
└── Vimix/

Install Via install.sh (preferred, When Available)

cd Vimix-4k
chmod +x install.sh
sudo ./install.sh

The installer typically copies theme files to /usr/share/grub/themes/, asks which resolution variant to use, and regenerates the GRUB config automatically.

Picking the Right Resolution Variant

Getting this wrong stretches or blurs the GRUB UI. Check the actual screen resolution first:

xrandr | grep '*'

If asked to pick, always choose the closest resolution at or below the actual screen resolution — never higher.

Manual Installation (no install.sh)

sudo cp -r theme-folder-name /usr/share/grub/themes/
sudo nvim /etc/default/grub

Add or update:

GRUB_THEME="/usr/share/grub/themes/theme-folder-name/theme.txt"

Regenerating the Grub Config

Ubuntu/Debian:

sudo update-grub

Fedora does not use update-grub:

# BIOS systems
sudo grub2-mkconfig -o /boot/grub2/grub.cfg

# UEFI systems (most modern laptops)
sudo grub2-mkconfig -o /boot/efi/EFI/fedora/grub.cfg

Check which mode a system is running in:

[ -d /sys/firmware/efi ] && echo UEFI || echo BIOS

On Fedora, themes commonly live under /usr/share/grub/themes/ — double-check theme.txt actually exists there and that GRUB_THEME points at it exactly.

If the Theme Doesn't Show Up

Usual suspects: Secure Boot blocking custom themes, a wrong theme.txt path, or a config that was never regenerated after the edit. Re-running the regenerate command for the relevant boot mode is the first thing to try:

sudo grub2-mkconfig -o /boot/efi/EFI/fedora/grub.cfg

Fedora + HiDPI tip: if GRUB renders too small on a 4K screen, add to /etc/default/grub and regenerate:

GRUB_GFXMODE=1920x1080
GRUB_GFXPAYLOAD_LINUX=keep