tmux Cheatsheet

#Mental Model

The server persists in the background. Detach from a session, close your terminal, reconnect later — everything is still running.

The Prefix Key

# All tmux keybindings start with a prefix (default: Ctrl-b).
# It's a SEQUENCE, not a chord: press Ctrl-b, release, then press the command key.
# This cheatsheet uses C-b to mean the prefix throughout.

C-b  =  Ctrl + b  →  release  →  <command key>

#Sessions

From the Shell

tmux                            # Start new unnamed session.
tmux new -s work                # Start session named "work".
tmux new -s work -n editor      # …with first window named "editor".
tmux ls                         # List all sessions.  Also: tmux list-sessions.
tmux a                          # Attach to last session.  Also: tmux attach.
tmux a -t work                  # Attach to session named "work".
tmux kill-session -t work       # Kill session named "work".
tmux kill-server                # Kill everything — all sessions, the server itself.

Inside tmux

#Windows

Windows are tabs. The status bar at the bottom shows them; * marks the active one.

# Reorder windows from command mode (C-b :)
swap-window -s 2 -t 0           # Move window 2 to position 0.
move-window -t 5                # Move current window to position 5.

#Panes

Creating & Navigating

Resizing & Rearranging

# Precise resize from command mode (C-b :)
resize-pane -D 10               # Grow down by 10 rows.   -U / -L / -R for other dirs.
resize-pane -t 2 -x 80          # Set pane 2 width to 80 columns.
resize-pane -t 2 -y 50%         # Set pane 2 height to 50% of window.

#Copy Mode

tmux has its own scrollback buffer. You must enter copy mode to scroll, search, or select text.

Entering & Navigating

Selecting & Copying (vi mode)

Space          # Start selection.
Enter          # Copy selection to tmux buffer and exit copy mode.
C-b ]          # Paste from tmux buffer.
v              # Toggle between character / line selection (if vi-mode).

System Clipboard Integration

# Add to ~/.tmux.conf to pipe copied text to system clipboard:

# macOS
bind -T copy-mode-vi y send -X copy-pipe-and-cancel "pbcopy"

# Linux (X11)
bind -T copy-mode-vi y send -X copy-pipe-and-cancel "xclip -sel clipboard"

# Linux (Wayland)
bind -T copy-mode-vi y send -X copy-pipe-and-cancel "wl-copy"

#Command Mode

C-b :                            # Open command prompt at bottom of screen.
                                  # Tab completion works. Any tmux command is valid.

Useful Commands

list-keys                        # Show all keybindings.     Also: C-b ?
list-commands                    # Show all available commands.
show-options -g                  # Show global options.
display-message "#S:#I.#P"       # Display current session:window.pane.
set -g mouse on                  # Enable mouse support live.  "off" to disable.
setw synchronize-panes on        # Type in all panes simultaneously.  Great for multi-
                                 # server commands.  "off" to disable.
capture-pane -pS -1000 | \
  save-buffer /tmp/tmux.log      # Dump 1000 lines of scrollback to a file.

#Configuration

Config lives at ~/.tmux.conf. Reload with: tmux source-file ~/.tmux.conf or from inside: C-b : → source-file ~/.tmux.conf

Practical Starter Config

# ── Prefix ──────────────────────────────────────────────
unbind C-b
set -g prefix C-a                # C-a is closer to home row (also screen compat).
bind C-a send-prefix             # Press C-a C-a to send literal C-a.

# ── Sane Splits ─────────────────────────────────────────
bind | split-window -h -c "#{pane_current_path}"
bind - split-window -v -c "#{pane_current_path}"
bind c new-window -c "#{pane_current_path}"

# ── Navigation ──────────────────────────────────────────
bind h select-pane -L            # vim-style pane movement.
bind j select-pane -D
bind k select-pane -U
bind l select-pane -R

# ── Mouse ───────────────────────────────────────────────
set -g mouse on                  # Click panes, resize with drag, scroll.

# ── Windows ─────────────────────────────────────────────
set -g base-index 1              # Start numbering at 1 (0 is far away).
setw -g pane-base-index 1
set -g renumber-windows on       # Close window 2 → window 3 becomes 2.

# ── Performance ─────────────────────────────────────────
set -sg escape-time 0            # No delay after pressing Escape (vital for vim).
set -g history-limit 50000       # Generous scrollback buffer.
set -g display-time 3000         # Messages stay visible 3 seconds.

# ── Copy Mode ───────────────────────────────────────────
setw -g mode-keys vi             # vi keybindings in copy mode.

# ── Status Bar ──────────────────────────────────────────
set -g status-style "bg=default,fg=white"
set -g status-left "#[bold]#S "
set -g status-right "%H:%M"

# ── True Color ──────────────────────────────────────────
set -g default-terminal "tmux-256color"
set -ag terminal-overrides ",xterm-256color:RGB"

Format Variables (for status bar customization)

#S  session name    #I  window index    #W  window name
#P  pane index      #T  pane title      #H  hostname
#F  window flags    #D  pane id         #{pane_current_path}

#Scripting & Automation

send-keys — Remote Control from Shell

# Send a command to a running session without attaching.
tmux send-keys -t work "make test" Enter

# Target a specific window and pane.
tmux send-keys -t work:2.1 "tail -f /var/log/app.log" Enter

# Target format:  session:window.pane
#                 work:2.1  →  session "work", window 2, pane 1

Session Bootstrap Script

#!/bin/bash
# Create a dev layout: editor + server + logs

tmux new-session -d -s dev -n editor
tmux send-keys -t dev:editor "vim ." Enter

tmux new-window -t dev -n server
tmux send-keys -t dev:server "npm run dev" Enter

tmux new-window -t dev -n logs
tmux split-window -t dev:logs -h
tmux send-keys -t dev:logs.0 "tail -f /var/log/app.log" Enter
tmux send-keys -t dev:logs.1 "tail -f /var/log/error.log" Enter

tmux select-window -t dev:editor
tmux attach -t dev

Hooks — React to Events

# Run a command whenever a new session is created.
set-hook -g after-new-session "run-shell 'notify-send tmux Session\\ started'"

# Auto-rename window based on running process.
setw -g automatic-rename on

#Workflows

Project Sessions

# One session per project. Switch between them instantly.
tmux new -s frontend             # React app, test runner, git
tmux new -s backend              # API server, DB console, logs
tmux new -s infra                # Terraform, monitoring, SSH tunnels

C-b s                            # Session picker — jump between projects in 1 second.

Pair Programming

# Two people attach to the same session — both see and type the same thing.
# Person A:
tmux new -s pair

# Person B (same machine or via ssh):
tmux a -t pair

IDE-Like Layout

# Window 1 "code": main editor (vim/nvim), zoomed most of the time
# Window 2 "run":  split — test runner on top, git on bottom
# Window 3 "db":   database REPL
#
# Use C-b z to zoom/unzoom the editor pane as needed.
# Use C-b 1 / C-b 2 / C-b 3 to jump between concerns.

Synchronized Panes

# Type in all panes at once — great for multi-server admin.
C-b :  →  setw synchronize-panes on
# Now every keystroke goes to all panes in the window.
C-b :  →  setw synchronize-panes off   # Turn it off when done.

#Troubleshooting

# "sessions should be nested with care, unset $TMUX to force"
# → You're in tmux and trying to start tmux. Use C-b c for a new window instead.
# → Or detach first (C-b d), then attach to the other session.

# Escape key is slow (vim users)
# → Add to config:  set -sg escape-time 0

# Colors look wrong
# → set -g default-terminal "tmux-256color"
# → set -ag terminal-overrides ",xterm-256color:RGB"

# Mouse scroll shows history instead of scrollback
# → set -g mouse on

# "no sessions" after reboot
# → tmux doesn't survive reboots natively.
# → Use tmux-resurrect plugin or recreate with a bootstrap script.

# Nested tmux (local → ssh → remote tmux)
# → C-b C-b sends prefix to inner tmux.
# → Or set a different prefix on the remote machine.

#Daily Reference

The 20 commands you'll use every day. Master these and you're competent.

Plugins Worth Knowing

# Plugin manager: github.com/tmux-plugins/tpm
# Install: git clone https://github.com/tmux-plugins/tpm ~/.tmux/plugins/tpm
# Then add to ~/.tmux.conf:

set -g @plugin 'tmux-plugins/tpm'
set -g @plugin 'tmux-plugins/tmux-sensible'     # Sane defaults everyone agrees on.
set -g @plugin 'tmux-plugins/tmux-resurrect'    # Save/restore sessions across reboots.
set -g @plugin 'tmux-plugins/tmux-continuum'    # Auto-save sessions every 15 minutes.
set -g @plugin 'tmux-plugins/tmux-yank'         # System clipboard integration.

run '~/.tmux/plugins/tpm/tpm'               # Must be last line.  C-b I to install plugins.