css - How can I effectively clean up styles in a large web site?

Question

Our web site has been under a constant development for a better part of the last five years. As it happens, pretty much all the styles for the site are in one big CSS file. With time this css file has grown to about 9,000 lines - and I'm sure some of those styles are not used any more and quite a few styles provide duplicate functionality.

The site is written with PHP/Smarty; there are over 300 smarty templates and the whole site contains over 1000 different pages (read - unique URLs). I'm sure it will continue growing - as will the CSS file.

What's the best way to clean up this file?

Update: Unfortunately, online parsers where I put in a URL won't work for me, as 75% of the site is behind username/password logins - and depending on login, there are half a dozen different roles, each of which has their own set of of pages. There are also transactional elements (online shop), where the pages are displayed after (for example) credit card payment is taken/processed. I doubt that any online tool would be able to handle any of these. Therefore if there's a tool, it would have to work on a source tree.

Answer 1

Short of going through each .tpl file and searching the file for the selectors manually, I don't see any other way.

You could of course use Dust-Me selectors, but you'd still have to go through each page that uses the .tpl files (not each url as I know that many of them will be duplicates).

Sounds like a big job! I had to do it once before and I did exactly that, took me a week.

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Another tool is a Firebug plugin called CSS Usage. As far as I read it can work across multiple pages but might break if used site-wide. Give it a go.

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Triumph! Check out the Unused CSS online tool. Type your index url into the field and voila, a few minutees later a list of all the used selectors :) I know you want the unused ones, but then the only work is finding the unused ones in the file (ctrl+f) and removing them :)

Make sure to use the 2nd option, they'll email you the results of the crawl of your entire webpage. Might take up to half an hour, but that's far better than a week. Take some coffee :)

Just tested it, works a treat :)