tmux playground

Try tmux online, in a real terminal.

Real tmux, running in this tab. Nothing to install and no account to make: start the terminal and you land at a prompt in a session called play, with nothing watching what you do in it.

Type it for me

sent to your terminal

Any of these starts the terminal first if it is not running yet. Detach with C-b d to get back to the plain shell.

Six openings

Split the active pane into left and right Split the window into panesC-bthen%
Create a new window at the first free index and make it current The prefix key and new windowsC-bthenc
Toggle zoom: the active pane fills the window, press again to restore Zoom a paneC-bthenz
Prompt for a new name for the current window Rename the session and a windowC-bthen,
Detach this client and return to the outside shell Detach and come backC-bthend
Enter copy mode; arrows move, C-a and C-e go to line start and end, q exits Copy text in copy modeC-bthen[

Every key, by level

100 in the course

Level 1 · Basics25

tmux new
tmux new -s name
tmux new -n name
C-bthenc
C-bthenC-b
C-bthen?
C-bthen/
C-bthent
C-bthen:
:neww -d -n name
:neww command
C-bthend
tmux attach -t name
tmux ls
tmux new -s name -n name command
tmux new -A -s name
C-bthen%
C-bthen"
:splitw -fv
:splitw -fhb
:splitw -d
C-bthenUp
C-btheno
C-bthenq
:kill-server

Level 2 · Intermediate30

C-bthen3
C-bthenn
C-bthenl
C-bthen$
C-bthen,
C-bthenx
C-bthen&
:kill-session -t name
C-bthenz
C-bthenC-Left
C-bthenM-Left
:resize-pane -R 20
C-bthenSpace
:select-layout name
C-bthenM-1
C-bthen}
C-bthenm
:swap-pane
C-bthen.
:swap-window
:movew -r
C-bthens
C-bthenw
Enter
t
X
:
C-bthenD
:attach -d -t name
:detach-client -a

Level 3 · Advanced20

C-bthen[
C-Space
M-w
C-Up
C-r
C-bthen]
C-bthen=
d
:setb -b old -n new
:saveb -b name path
:loadb -b name path
C-bthenf
C-s
n
:set -g mouse on
:bind MouseDown1Pane
:bind MouseDown1Status
C-bthen!
:join-pane -s src
:send-keys -t target keys

Level 4 · Configure25

:show -g option
:set -g option value
:set -gu option
:echo 'set -g mouse on' >> ~/.tmux.conf
:source ~/.tmux.conf
:bind M-0 selectw -t:=10
:bind -n M-n next-window
:unbind M-0
:set -g prefix C-a
:bind C-a send-prefix
:set -g status-position top
:set -g status-style bg=red
:set -g status-right '%H:%M'
:set -g status-left '#{session_name}'
:#[fg=red]
:set -g status-left-length 40
:set -g status-right '#(cmd)'
:set -g status-interval 5
:set -g pane-border-style fg=red
:set -g pane-active-border-style 'fg=red,bg=yellow'
:set -g pane-border-status top
:set -g mode-keys vi
:bind -T copy-mode-vi v send -X begin-selection
:bind -Tcopy-mode MouseDragEnd1Pane send -X copy-selection-no-clear
:unbind -Tcopy-mode MouseDragEnd1Pane

The cheat sheet says what each one does →

What you are typing into

A real Linux machine running tmux with its stock settings, not a recording of one. It is the same terminal the 42 lessons use, with the grading taken off.

The machine runs inside this tab. Nothing you type is sent anywhere, and there is no account to make. The first start downloads about 15 MB and your browser keeps it, so after that it opens in a couple of seconds.

Starting it puts your keyboard in the terminal, and everything you press goes to the machine from then on, Tab included. Press Shift-Tab to step back out to the page.

Nothing is saved. The machine lives as long as the tab does, and Reset hands you a clean one whenever you want, so kill the server or fill the disk if you feel like it.

Questions

Is this really tmux?

Yes: tmux 3.4, on a real Linux kernel. Every key does what it does on a machine you would ssh into, because it is the same program.

Do I need to install anything?

No. A browser is the whole requirement, and there is nothing to sign up for.

Does it work on a phone?

It starts, but tmux hangs off a prefix key, C-b, and a phone keyboard has no Ctrl. Read here, play on a laptop.

Is my work saved between visits?

No. Sessions here are gone when the tab closes. Detaching withC-bthend and reattaching works exactly as it does on a real machine, but only while the tab is open.

I would rather be taught than handed a prompt.

Then start the course: 42 tasks across 4 levels, each one in a terminal like this one, with the checks ticking themselves off as you get things right. Start with the basics, or take the cheat sheet with you.

A real terminal, in this tab

about 15 MB, once

free play