Editing Cloaking (section)

{{Short description|Search engine optimization technique}}
{{For|cloaking as used in science fiction|Cloaking device}}
{{For|cloaking as used in extended DOS device drivers|Helix Cloaking}}

{{More citations needed|date=October 2021}}
'''Cloaking''' is a [[search engine optimization]] (SEO) technique in which the content presented to the [[search engine spider]] is different from that presented to the user's [[Web browser|browser]]. This is done by delivering content based on the [[IP address]]es or the [[User-Agent]] [[HTTP]] header of the user requesting the page. When a user is identified as a search engine spider, a server-side [[Scripting language|script]] delivers a different version of the [[web page]], one that contains content not present on the visible page, or that is present but not searchable. The purpose of cloaking is sometimes to deceive [[search engine]]s so they display the page when it would not otherwise be displayed ([[black hat hacking|black hat]] SEO). However, it can also be a functional (though antiquated) technique for informing search engines of content they would not otherwise be able to locate because it is embedded in non-textual containers, such as video or certain [[Adobe Flash]] components. Since 2006, better methods of accessibility, including [[progressive enhancement]], have been available, so cloaking is no longer necessary for regular SEO.<ref>{{cite web |title=Cloaking {{!}} Google Search Central |url=https://developers.google.com/search/docs/advanced/guidelines/cloaking |website=Google Developers |language=en}}</ref>

Cloaking is often used as a [[spamdexing]] technique to attempt to sway search engines into giving the site a higher ranking. By the same method, it can also be used to trick search engine users into visiting a site that is substantially different from the search engine description, including delivering [[pornography|pornographic]] content cloaked within non-pornographic search results.

Cloaking is a form of the [[doorway page]] technique.

A similar technique is used on [[DMOZ]] [[web directory]], but it differs in several ways from search engine cloaking:
* It is intended to fool human editors, rather than computer search engine spiders.
* The decision to cloak or not is often based upon the HTTP [[referrer]], the user agent or the visitor's IP; but more advanced techniques can be also based upon the client's behaviour analysis after a few page requests: the raw quantity, the sorting of, and latency between subsequent HTTP requests sent to a website's pages, plus the presence of a check for [[robots.txt]] file, are some of the parameters in which search engines' spiders differ heavily from a natural user behaviour. The referrer tells the [[Uniform Resource Locator|URL]] of the page on which a user clicked a link to get to the page.  Some cloakers will give the fake page to anyone who comes from a web directory website, since directory editors will usually examine sites by clicking on links that appear on a directory web page.  Other cloakers give the fake page to everyone ''except'' those coming from a major search engine; this makes it harder to detect cloaking, while not costing them many visitors, since most people find websites by using a search engine.