How to change the default position of quickfix window in Vim?

While it is not possible to change the default split-window behavior of the :copen command, one can approach the issue in two ways.

1. Use the commands that directly alter window splitting directions (see :help :vertical and below until the “Closing a window” paragraph).

For instance, consider the commands:

:botright copen

or

:botright cwindow

to make the quickfix window open as the bottommost one, or even:

:vertical topleft cwindow

to open it to the top left of the current window.

These commands can be shortened to :bo cope, :bo cw, and :vert to cw, respectively. Also, one can, of course, create a short mapping or a custom command for their quick invocation.

2. Alternatively, move the quickfix window to the bottom of the window layout using an auto-command:

:autocmd FileType qf wincmd J

This trigger takes advantage of the fact that the quickfix window can be easily distinguished by its file-type, qf. The wincmd J command is equivalent to the [Ctrl+W, Shift+J] shortcut sequence instructing Vim to move the current window to the very bottom of the screen (see :help :wincmd and :help ^WJ).

By default, Vim opens the new window above the current one for horizontal splits, and to the left of the current one for vertical splits (:help opening-window). You can customize this behavior like most other things in Vim:

make the new window appear below the current window.

:set splitbelow

make the new window appear on the right.

:set splitright