Toggle last active pane
panes
// what it does
Ctrl+b ; jumps to the previously active pane (last-pane), toggling back and forth between two panes. It's the pane-level analog of last-window (Ctrl+b l). Ideal for bouncing between an editor and a shell without cycling through everything in between.
// shortcut
Ctrl + b;
// gotcha
It only remembers the single most-recent pane, so it's a two-pane toggle, not a history stack. If you've only ever focused one pane, it does nothing.