If you have a large number of windows open in tmux, it can be a pain when deleting some of them as the numbers are no longer consxistent.   You could have 20 windows open, but the next window you create will be #2 because that was the first free spot.

A quick way to fix this is to run :movew -r which will renumber all existing windows.  

Note: Older versions of tmux may not have the -r option.

:movew without any arguments can be run to renumber the current window only to the first available spot.

And :movew -t <num> can be used to renumber the current window to a specific index.


Help for the move-window command:

move-window[-ardk] [-s src-window] [-t dst-window] This is similar to link-window except the window at src-windowis moved to dst-window With -r all windows in the session are renumbered in sequential order, respecting the base-indexoption.