Install instructions

1. Copy resize-font to where URxvt looks for it's Perl extensions (see urxvt(1) man-page on perl-lib)

2. In your ~/.Xresources add resize-font to the urxvt.perl-ext-common setting so URxvt loads the extension, e.g:

    urxvt.perl-ext-common: default,tabbed,matcher,resize-font,-tabbed
   

3. See header of resize-font for standard keybinds and how to change them.

Note that this extension requires you to set your font size with urxvt.font. For more information, see header of resize-font.