tmux Installation and Configuration: First Setup Guide (2026)

tmux is a terminal multiplexer that lets you run multiple terminal sessions within a single window, detach from them, and reattach later.

Here’s how to get it set up and running:

Installation

On most Linux and macOS systems, you can install tmux using your system’s package manager.

Debian/Ubuntu:

sudo apt update
sudo apt install tmux

Fedora/CentOS/RHEL:

sudo dnf install tmux
# or
sudo yum install tmux

macOS (using Homebrew):

brew install tmux

Once installed, you can launch tmux by simply typing tmux in your terminal and pressing Enter. You’ll see a status bar appear at the bottom of your screen, indicating you’re now inside a tmux session.

Basic Navigation and Commands

tmux commands are typically prefixed by a "prefix key" followed by another key. The default prefix key is Ctrl+b.

• Ctrl+b then c: Create a new window (like a new tab).
• Ctrl+b then n: Switch to the next window.
• Ctrl+b then p: Switch to the previous window.
• Ctrl+b then 0 to 9: Switch to a specific window by its number.
• Ctrl+b then &: Kill the current window.
• Ctrl+b then %: Split the current pane vertically (creating two side-by-side panes).
• Ctrl+b then ": Split the current pane horizontally (creating two stacked panes).
• Ctrl+b then Arrow Key: Navigate between panes.
• Ctrl+b then x: Kill the current pane.
• Ctrl+b then d: Detach from the current tmux session. The session continues running in the background.

To reattach to a detached session, type tmux attach or tmux a. If you have multiple sessions, you can list them with tmux ls and attach to a specific one using tmux attach -t <session_name>.

Configuration: .tmux.conf

The real power of tmux comes from customization. You can create a configuration file at ~/.tmux.conf to change keybindings, colors, and behavior.

Let’s set up a more convenient prefix and some common settings.

Create or edit ~/.tmux.conf and add the following:

# Change the prefix key to Ctrl+a
set -g prefix C-a
unbind C-b

# Set the window and pane base index to 1
set -g base-index 1
setw -g pane-base-index 1

# Enable mouse mode for easier pane selection and scrolling
set -g mouse on

# Set up keybindings for window splitting and pane navigation
# Split pane horizontally
bind '-' split-window -v
# Split pane vertically
bind '|' split-window -h

# Navigate panes with arrow keys
bind -r h select-pane -L
bind -r j select-pane -D
bind -r k select-pane -U
bind -r l select-pane -R

# Resize panes with Ctrl+Arrow Keys (using the new prefix C-a)
bind C-h resize-pane -L 5
bind C-j resize-pane -D 5
bind C-k resize-pane -U 5
bind C-l resize-pane -R 5

# Reload the config file
bind r source-file ~/.tmux.conf \; display "Reloaded!"

# Set status bar colors (optional, for a nicer look)
set -g status-bg 'colour235'
set -g status-off on

After saving ~/.tmux.conf, you need to reload the tmux configuration. If you’re already in a tmux session, press your new prefix (Ctrl+a) then r. If you’re not in a session, you can start a new one with tmux and then press Ctrl+a then r.

With this configuration:

• Your prefix is now Ctrl+a.
• You can split panes with Ctrl+a then - (horizontal) or Ctrl+a then | (vertical).
• You can navigate between panes using Ctrl+a then h, j, k, or l.
• You can resize panes using Ctrl+a then Ctrl+h, j, k, or l.
• Mouse mode is enabled, allowing you to click on panes to select them and scroll with your mouse wheel.

This setup provides a solid foundation for using tmux efficiently for managing multiple terminal tasks.

The next step is to explore session management and more advanced pane/window manipulation.