[Zikes]

I honestly think this needs to be a part of Chrome Dev Tools's profiler. Already it's able to record sessions that persist across page loads, and tracks what CSS selectors are applied and which properties are overridden. I don't think it's much of a stretch to add a feature like this.

[spanktar]

+1 for something along these lines to be available in all vendor's dev tools!

[WhiteNoiz3]

Agreed! We need something that collects data from multiple pages as you browse through and use your site. At the end it gives you a table of all your classes that didn't match anything (with line number references to your css file).

[Existenceblinks]

Though you need to manually visit all those pages. And it wouldn't be easy to traverse DOM with those server side logic/condition.

IMHO, do it offline and out of browser would be easier. But I also think doing it directly with the codes can be hard too since there are so many way that those css will be added to templates.

[LoSboccacc]

Unless the pages are dynamically generated