What is cloaking?
I’m glad you asked. Put simply, cloaking is when a website shows different content to a search engine spider than it does to normal visitor.
Why would a site do this?
It’s almost always a blackhat SEO technique that aims to show search engines a keyword rich page that bears little resemblance to the actual page, in order to appear more relevant for a search term, and therefore improve the ranking of that page.
How’s it done?
When requesting a website from the server all browsers send certain “headers” before the server responds with the contents of the page. One such field is the “User-Agent” field which declares which browser is in use.
My User-Agent for instance is:
Mozilla/5.0 (Windows; U; Windows NT 6.1; en-GB; rv:1.9.2) Gecko/20100115 Firefox/3.6
Memorable, I’m sure you’ll agree.
Google declare themselves with the User-Agent “Googlebot” when crawling your pages so by detecting this, a black hat site can present different information based on who is visiting. Yahoo! has “Slurp” and Bing uses “msnbot” as their User-Agent. Rather than use the User-Agent field, the same can be achieved by looking at the IP address of the visitor, since search engines use a certain IP range when crawling.
Does it work?
No. Not with Google at least. It used to work, and was probably one of the more advanced Blackhat SEO tactics back in the Wild West SEO days. As Google say in their Webmaster guidlelines: “Make pages primarily for users, not for search engines.”.
The reason it doesn’t work now (and hasn’t for a number of years for that matter) is because Google will visit your pages once using the “Googlebot” User-Agent, and another time as a typical browser (say, Firefox) declaring themselves as a normal visitor. It can then compare the two versions of the page to see if there’s a significant difference.
And if you’re site uses cloaking, you’re a goner…
How do I detect it?
To detect if your competitors site is using cloaking techniques, you have a few options. You can use the cache link next to the search result to see what the search engine saw when they visited. You can then compare that to the live site.
Alternatively, you can fake your own User-Agent and visit the site as if you were a search engine. Get the User Agent Switcher for Firefox and away you go. This last one will only reveal cloaked content if the site is detecting the User-Agent, rather than the IP address. So for a one-size-fits-all approach, go with the cache idea.
More information
More information about cloaking can be found on Google’s help pages, particularly this one.
This blog was written over 6 months ago and Internet Marketing and SEO is an always changing industry which means the information within this blog may be out of date. Use caution when using any methods or suggestions within it.