You can run the same command in all active Tmux panes at the same time.

You need to activate command mode in Tmux with Ctrl+B keys and update synchronize-panes setting to on.

:setw synchronize-panes on

To disable it, set as off.

:setw synchronize-panes off

You can toggle synchronize-panes setting without use on-off parameters.

:setw synchronize-panes

#tmux #tips