Does Google read your CSS files?
Many webmasters reported that Google's spider
started to index their external CSS files. What are CSS files,
why does Google index them and how can this affect your rankings
on Google and other search engines?
What are CSS files?
CSS (Cascading Style Sheets) files allow
webmasters to specify the layout of a web site without
touching the HTML code. A good example is the CSS
Zen Garden site.
On that web site, you can change the complete
look of the site by selecting different style sheets. The
HTML code of the page is always the same, only the CSS
file that is used to display the HTML code changes.
What's the problem with CSS files?
CSS allow webmasters to design their web
pages without touching the HTML code. That also means that
webmasters can use that technique to hide content from
their web site visitors.
Webmasters can put keyword rich content in
the HTML code of their web pages that search engines can
index. The same text can be hidden from human web surfers
by using CSS.
That means that search engines see something
totally different than human web surfers. Unfortunately,
some webmasters try to fool search engines with that technique.
What do search engines do about this
Search engines don't want to be fooled by
webmasters. For that reason, they started to index CSS
files. If search engines find anything that looks like
spamming in a CSS file, they might penalize the corresponding
What can you do to avoid problems with
your CSS files?
Unfortunately, it's not clear yet what search
engines consider spamming and what not. There are many
legitimate uses for hiding text on a web site so it's hard
to tell what search engines will penalize.
As a rule of thumb, don't try to cheat search
engines. If you do something explicitly to cheat search
engines then chances are that search engines will detect
this and penalize your site sooner or later.
Ask yourself if it is really necessary to hide
text on your web site. If it might be misinterpreted as spamming
by human web surfers, don't hide text on your site. Don't
use shady techniques to promote your web site. Better
focus on ethical SEO methods.