Tmux Tutorial¶

2026-01-12

Tmux is a terminal multiplexer that lets you run multiple terminal sessions inside a single window.

This tutorial is based on my custom tmux.conf. It makes tmux more ergonomic and significantly prettier, without bloated plugins. It may not be the best conf, but it's mine.

Why Tmux?¶

Tmux makes it easy to multitask across many projects in different sessions, with one or more Claude Code instances running in each session.

Installation (Ubuntu)¶

sudo apt update
sudo apt install tmux

Check the version with tmux -V. If you need a newer release than what Ubuntu ships (the config below relies on reasonably recent tmux features like display-popup), build from source or grab a backport - see the tmux wiki.

Setting Up tmux.conf¶

Grab my config and drop it in as ~/.tmux.conf before you start tmux for the first time:

curl -o ~/.tmux.conf https://raw.githubusercontent.com/vivainio/dotfiles/master/tmux.conf

The popups in Level 5 call out to lazygit and lf - install those separately if you want those bindings to work:

sudo apt install lazygit lf

(Ubuntu's apt may only have an old lazygit; if so, install it from the lazygit releases page instead.)

Custom Prefix¶

The default tmux prefix Ctrl+b is replaced with Ctrl+Space. This is more ergonomic and allows you to execute all chords quickly. Combined with Alt+arrow navigation, everything becomes even easier.

Level 1: Tabs¶

Tmux calls tabs "windows". Here's the essentials:

Action	Binding
Create new tab	`Prefix + c`
Kill current tab	`Prefix + k`
Close other tabs	`Prefix + o`
Next tab	`Alt+Right`
Previous tab	`Alt+Left`

No prefix needed for navigation - just hold Alt and press arrow keys.

Modern shells and Claude Code change the tab title based on what's happening in the window. Normally this would go to the terminal window title, but tmux captures it and renders it as the tab title within the window.

Level 2: Sessions¶

Sessions let you group tabs for different projects. Switch between entire sessions instantly.

Action	Binding
New session	`tmux new -s name`
Next session	`Alt+Down`
Previous session	`Alt+Up`
List sessions	`Prefix + w`
Kill session	`Prefix + K`
Detach	`Prefix + d`

All new tabs in a session start in the same directory where you created the session. This makes sessions ideal for grouping related work - one session per project, and every tab opens ready to go in that project's folder.

Prefix + w opens the tree view, showing all sessions, tabs, and panes with a preview of each:

  backend
  ├─ 1: claude
  ├─ 2: server
  └─ 3: tests
  frontend
  ├─ 1: claude
  └─ 2: dev
  notes
  └─ 1: claude

This makes it easy to peek at ongoing work and jump back to it. Type / to search within the tree by name.

Prefix + d detaches from tmux, leaving all sessions running in the background. Reattach with tmux a, or start a new session with tmux new -s name.

Level 3: Panes¶

Panes let you split a tab into multiple views. I'll admit I don't use panes as much as I should - I tend to reach for new tabs instead. But they're useful when you want to see two things side by side.

Action	Binding
Split vertically	`Prefix + %`
Split horizontally	`Prefix + "`
Kill pane	`Prefix + x`
Switch pane	`Prefix + arrow keys`

Level 4: Copy Mode¶

Scrolling up with the mouse wheel enters copy mode automatically - this can catch you off guard, so just press q to exit back to normal mode and scroll back to the bottom, ready to continue typing. You can also enter copy mode explicitly with Prefix + Enter.

Action	Key
Navigate	arrow keys
Search	`/` (forward), `?` (backward), `n`/`N` to jump between matches
Start selection	`Space`
Copy	`Enter`
Paste tmux buffer	`Prefix + ]`
Exit	`q`

Level 5: Extensibility¶

Tmux is highly scriptable. My config uses display-popup to launch apps in floating windows that appear over your current work and close when you're done:

Popup	Binding
lazygit	`Prefix + Ctrl+G`
lf file manager	`Prefix + Ctrl+L`
Daily notes editor	`Prefix + Ctrl+N`

Lazygit is launched with --screen-mode half for comfortable diff viewing, and opens in the tab's working directory.

Q&A¶

Why not Zellij?

Tmux is more mature and a much smaller application. It's not written in Rust (yet), but it does everything it needs to do and can be extended to the rest.

Seriously, why??

With the advent of AI, there is growing ability to multitask. Multitasking is made much easier if you have full sessions that contain the context for one task, and can easily hop to other sessions with next steps waiting for you. In IDEs it's easy to get lost among windows and blinking lights, while terminal sessions stay very focused on an individual task.

Herdr Tutorial applies a similar workspace model to a multiplexer designed around coding agents.
My Vibing Flow shows this tmux setup as part of a complete development workflow.