The HTTP Referer header is a header that is transmitted with the HTTP request when a link is clicked on one page and a new page is requested through HTTP.

This allows Analytics to track where a user is coming from or what path a user is following on the site.

Caveat

HTTP Referer headers are not transmitted when following a link from an https: page to an http: page.

Since sites like google.com are running on https: , it is sometimes impossible to see search referals coming from them.

See also

• Referer Types
• Smerity.com : Explanation about lost HTTP referers and introduction of the meta referer tag.