Does CSS help your Search Engine Optimisation?

We were just asked: “I was under the impression that for SEO purposes CSS usage was better than tables. I recently heard that CSS is ignored by the search engines”.

Search engines change their behaviour constantly, and it is always kept secret, so the best answer anyone can give involves a degree of research and guesswork. SEO researchers constantly try different strategies and notice successful patterns in what does or doesn’t work, as do we.

The CSS code itself appears to be ignored by search engines, and there’s not much apparent benefit to them looking at it; the whole point of CSS is that it adds presentation to the content of your pages, not content itself. (One exception: detecting black hat CSS techniques, like keyword stuffing in invisible regions).

However, using CSS properly does enable your pages to be smaller and load faster, which has some positive effect on SEO. It also allows the code in your pages to be ordered in a way that can emphasise certain content, allowing potentially better SEO. For example, using CSS you can present the content for your pages higher in your code (as Google sees it) than say your navigation.

CSS is one technology to use as part of an SEO strategy, but it’s no panacea. Of course, CSS is great for lots of other reasons – like accessibility, printability, maintainability -  and you’d be hard pressed to make a modern site without it now, so our recommendation is simple: use CSS, and use it properly.