How to attach to a tmux session

Reattach to a session (tmux a is enough if there's only one):

The standard reconnect flow

SSH back in, run tmux ls to see what's running, then tmux attach -t name. Everything is exactly where you left it — that's the entire reason tmux exists.

Window full of dots? (the small-client problem)

If your session appears shrunken with a border of dots, another (often dead) client is attached from a smaller terminal — tmux sizes to the smallest attached client by default. Fix it now with tmux attach -d (detaches the others), or permanently:

~/.tmux.conf
set -g window-size latest
setw -g aggressive-resize on

Related

Verified against tmux 3.6 · updated July 2026 · back to the full cheat sheet