C-b % Create new pane on the right of current pane tmux split-window -h vi Split horizontal and run vi in it C-b Left, C-b Right, C-b Up, C-b Down Go to pane by direction C-b C-Left, C-b C-Right, C-b C-Up, C-b C-Down Resize the pane C-b M-Left, C-b M-Right, C-b M-Up, C-b M-Down Resize the pane in 5x steps A window can be split into panes. By default new window has only one pane occupying all spaces.