To insert space characters whenever the tab key is pressed, set the 'expandtab' option: :set expandtab With this option set, if you want to enter a real tab character use Ctrl-V key sequence. To control the number of space characters that will be inserted when the tab key is pressed, set the 'tabstop' option. For example, to insert 4 spaces for a tab, use: :set tabstop=4 :retab To change the number of space characters inserted for indentation, use the 'shiftwidth' option: :set shiftwidth=4 For example, to get the following coding style, use the following set of options: