You could try looking in the Google cache to see if it matches the content of the website.
Tried that before as I had my suspicion that a particular site was cloaking. When I checked Google cache it showed a blank white page hmmmm. Then I clicked "This cached page may reference images which are no longer available. Click here for the cached text only."
If it was that simple to detect cloaking then it would defeat the whole point of cloaking...
Assuming someone knows what they are doing when it comes to cloaking then you shouldn't be able to detect it at all - the suggestions laid out here all rely on errors on the part of the cloaker allowing you to detect them.
Tony is right. The only way to tell if somebody is cloaking (when done right) is to look at the SERPs and see if the title is the same as that on the web page and if the snippet of text exists on the web page. Even that isn't 100% accurate.
There is no foolproof way to access the html shown to search engines. Every method I've ever seen to access the optimized html has been protected against by most commercial cloaking software packages.
> There is no foolproof way to access the html shown to search engines. Every method I've ever seen to access the optimized html has been protected against by most commercial cloaking software packages.
Huh? Just connect to the site giving googlebot as the User Agent and you will see the page that the site serves up to google. Have you got the URL of the cloaked site? cURL will let you do this.
Ok but is that very effective? If I were, say Google, I would randomize the IP addresses used by my robots.
Yup, it's very effective when used in conjunction with user agent detection. Google only have so many IP addresses - and the ones they crawl from do change, but good cloaking software updates IP ranges as Google does.
I've never used cloaking software though - I'm sure that there's other stuff that goes into it as well - a lot of people around here could jump in and explain it and if you look at the library of this forum you'll find that some people already have.