tmux: Stop Losing Your Terminal Sessions (Quick Start Guide)

Why tmux?

Three problems tmux solves:

1. Session persistence — SSH into a server, start a build, network drops. Without tmux: build dies. With tmux: it keeps running, you reconnect and attach.

2. Multiple panes — split your terminal into panes. Run the server in one, logs in another, tests in a third. All in one window.

3. Session management — named, persistent sessions for different projects. Switch between them like browser tabs.

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Installation

# macOS
brew install tmux

# Ubuntu/Debian
sudo apt install tmux

# Fedora/RHEL
sudo dnf install tmux

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Core Concepts

• Session — a collection of windows. Persists even when you disconnect.
• Window — like a browser tab. Contains panes.
• Pane — a split region within a window.

All tmux commands start with the prefix key: Ctrl+B by default.

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Essential Commands

Sessions

# Start a new named session
tmux new -s myproject

# List all sessions
tmux ls

# Attach to a session
tmux attach -t myproject
# or just:
tmux a -t myproject

# Detach from current session (keep it running)
Ctrl+B d

# Kill a session
tmux kill-session -t myproject

Panes (splitting)

Ctrl+B %    — Split horizontally (left/right)
Ctrl+B "    — Split vertically (top/bottom)
Ctrl+B ←↑↓→ — Navigate between panes
Ctrl+B z    — Zoom (maximize) current pane / unzoom
Ctrl+B x    — Close current pane

Windows

Ctrl+B c    — Create new window
Ctrl+B ,    — Rename current window
Ctrl+B n    — Next window
Ctrl+B p    — Previous window
Ctrl+B 0-9  — Switch to window by number
Ctrl+B w    — List all windows (interactive)

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A Practical Workflow

# Start a session for your project
tmux new -s api-project

# Layout: server | editor | tests
Ctrl+B "        # Split top/bottom
Ctrl+B %        # Split bottom-left/bottom-right

# Pane 1 (top): server
npm run dev

# Navigate to pane 2 (bottom-left)
Ctrl+B ↓
# Pane 2: editor or file watching
vim src/api.ts

# Navigate to pane 3 (bottom-right)
Ctrl+B →
# Pane 3: tests
npm test -- --watch

# Detach — everything keeps running
Ctrl+B d

# Come back later
tmux attach -t api-project

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Customize tmux: ~/.tmux.conf

The default config is usable but not ideal. Recommended settings:

# ~/.tmux.conf

# Change prefix to Ctrl+A (screen-style, easier to type)
set -g prefix C-a
unbind C-b
bind C-a send-prefix

# Intuitive pane splits (| and -)
bind | split-window -h -c "#{pane_current_path}"
bind - split-window -v -c "#{pane_current_path}"

# Vim-style pane navigation
bind h select-pane -L
bind j select-pane -D
bind k select-pane -U
bind l select-pane -R

# Enable mouse support
set -g mouse on

# Increase scrollback history
set -g history-limit 50000

# Start windows and panes at 1 (easier to reach on keyboard)
set -g base-index 1
setw -g pane-base-index 1

# Reload config with prefix + r
bind r source-file ~/.tmux.conf \; display "Config reloaded"

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

Apply changes: Ctrl+B r (after adding the reload binding) or tmux source ~/.tmux.conf.

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Copy Mode: Scrolling and Copying

Ctrl+B [    — Enter copy mode (scroll freely with arrow keys / PageUp/Down)
q           — Exit copy mode
Ctrl+B ]    — Paste buffer

In copy mode with vi keys enabled:

# ~/.tmux.conf
setw -g mode-keys vi

v   — start selection
y   — yank (copy)
/   — search forward

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Key Takeaways

• Sessions persist after disconnect — attach with tmux attach -t name
• Prefix key: Ctrl+B (or remap to Ctrl+A)
• % and " split panes; arrow keys navigate
• d to detach (session keeps running), $ to rename session
• Set mouse on in .tmux.conf — scroll with mouse in any pane
• Use named sessions per project — tmux new -s myproject