How to change the tmux prefix key — Ctrl-b to Ctrl-a

Ctrl-b is awkward or clashes with your editor — the classic fix is moving the prefix to Ctrl-a.

tmux's default prefix is Ctrl-b: “prefix c” means press Ctrl-b, let go, then press c. Every CLI command was run for real against tmux 3.4 in detached test sessions, and every prefix binding was checked against the default binding table.

set -g prefix C-a        # use Ctrl-a as the prefix…
unbind C-b               # …free the default Ctrl-b binding…
bind C-a send-prefix     # …and let prefix C-a send a literal Ctrl-a to the program

Good to know

send-prefix matters: without it, programs that themselves use Ctrl-a (shells, editors) can never receive it.

tmux Cheatsheet one-page card — commands that actually work — The full one-page card — tmux Cheatsheet. Get the complete cheatsheet on GitHub