Remapping Caps Lock To Control On Linux: X11 And Wayland

Remapping Caps Lock to Control is a worthwhile investment if you spend significant time in Emacs or vim. Your pinky will benefit from years of reduced strain.

Desktop Environment Settings (Easiest)

Most modern desktop environments include a built-in option for this remapping.

GNOME (40+):

Open Settings → Keyboard → Special Character Options
Toggle “Make Caps Lock an additional Control”

KDE Plasma:

Open System Settings → Input Devices → Keyboard
Go to the Advanced tab and find the Caps Lock option
Select “Make Caps Lock an additional Control”

XFCE:

Settings → Keyboard → Layout tab
Click “Layout Options” button
Under “Caps Lock behavior”, select “Make it an additional Control”

This is the simplest approach and works across both X11 and Wayland. If your DE supports it, use this first.

X11: setxkbmap (Recommended for X11)

For X11 systems where DE settings don’t suffice, setxkbmap is cleaner than the older xmodmap approach:

setxkbmap -option ctrl:nocaps

Verify it’s active:

setxkbmap -query

To revert:

setxkbmap -option ''

Making it Persistent on X11

Add the command to your X11 startup. Choose one based on your setup:

For startx users, add to ~/.xinitrc:

setxkbmap -option ctrl:nocaps

For display managers (GDM, LightDM, SDDM), create ~/.xsession:

#!/bin/bash
setxkbmap -option ctrl:nocaps
exec dbus-launch --exit-with-session your-window-manager

Make it executable:

chmod +x ~/.xsession

For systemd user sessions, create ~/.config/autostart/setxkbmap.desktop:

[Desktop Entry]
Type=Application
Exec=setxkbmap -option ctrl:nocaps
Hidden=false
Name=Caps Lock Remapping

X11: xmodmap (Legacy, When setxkbmap Won’t Work)

If setxkbmap doesn’t work for your keyboard layout, xmodmap provides lower-level control.

First, find the Caps Lock keycode:

xev | grep -A 2 "KeyPress"

Press Caps Lock and look for output like:

state 0x0, keycode 66 (keysym 0xffe5, Caps_Lock)

Create or edit ~/.Xmodmap:

clear Lock
keycode 66 = Control_L
add Control = Control_L Control_R

Apply immediately:

xmodmap ~/.Xmodmap

Make it persistent using the same ~/.xinitrc, ~/.xsession, or ~/.config/autostart/ methods shown above, but call xmodmap ~/.Xmodmap instead.

Wayland: systemd-localed

On Wayland, neither xmodmap nor setxkbmap work. Instead, use localectl:

sudo localectl set-x11-keymap us '' '' ctrl:nocaps

Replace us with your keyboard layout if needed. This persists across reboots on systemd systems.

Verify the setting:

localectl status

If you want to also apply it to the current Wayland session immediately (on GNOME or KDE), also run through your DE’s Settings as shown above.

Testing and Troubleshooting

After applying any method, test in Emacs or a text editor:

C-a   # Move to beginning of line
C-e   # Move to end of line
C-k   # Kill to end of line

Settings don’t persist after reboot:

Verify your script is executable: ls -l ~/.xsession or ls -l ~/.Xmodmap
Check that your shell is sourcing startup files: echo $SHELL and verify ~/.bashrc sources ~/.bash_profile if needed
For systemd user sessions, ensure ~/.config/autostart/ is correct and verify with systemctl --user status graphical-session.target

Changes don’t take effect immediately:

Log out and back in, or restart your display server (killall X for X11, then log out)
For Wayland, changes from localectl require a full logout/login cycle

Keycode varies by keyboard:
The keycode shown above (66) is standard for most keyboards, but ergonomic or international layouts may differ. Always verify with xev first.

Muscle Memory Across Systems

If you frequently switch between machines where Caps Lock isn’t remapped, expect a transition period. Muscle memory typically adapts within 2–4 weeks. Consider remapping on all your regular systems to avoid constant context-switching.

Remapping Caps Lock to Control on Linux: X11 and Wayland