I have used a Firefox extension called Dust-Me Selectors[1] which does this. It breaks your css into used and unused selectors, it can spider the site for you,

I have used a Firefox extension called Dust-Me Selectors[1] which does this. It breaks your css into used and unused selectors, it can spider the site for you, or you can leave it running as you browse the site and it will work automatically. Definitely slows things down though while you're using it. 1: https://addons.mozilla.org/en-US/firefox/addon/dust-me-selectors/?src=search https://addons.mozilla.org/en-US/firefox/addon/dust-me-selec...