Whois is a specific protocol that can be used to retrieve information about the owners and Admin-C of Domains. “Whois queries” are offered by many different vendors, such as webhosts. Background information on .de domains can only be accessed via the DENIC.


When the Internet was still in its infancy, all domains were registered with only one registrar, DARPA (Defense Advanced Research Projects Agency). Anyone looking for information on individual web addresses could use this source. Because of the growing number of domains, more and more registrars came into existence. At the same time, the number of illegitimate domain information queries increased. For example, many spammers use the whois query to get email addresses of webmasters. Therefore, more strict policies apply to whois data access. Captcha queries are supposed to safeguard the data from automated access by Bots.

Result of a whois query[edit]

The whois data usually contain information that can also be found in the imprint of the respective website. In addition, the query contains information on the web host that is used for the relevant domain as well as the contact details for the technical contact and the person who registered this domain. An important key figure of the whois data is also the date when the domain registration expires.

A whois query can therefore be compared with an extract from the land register. The whois databases are accessible through the servers of the following organizations:

  • RIPE NCC (RIPE Network Coordination Center)
  • ARIN (American Registry for Internet Numbers)
  • APNIC (Asia-Pacific Network Information Center)
  • LACNIC (Latin American and Caribbean Network Information Center)
  • AfriNIC (African Network Information Center)

Benefits for SEO[edit]

The whois data provides SEOs important clues for their work, which are briefly listed here:

  • Control of the whois data, whether a web page is reputable
  • Option to check whether the registrant has other domains, and whether the domain concerned may be part of a link network
  • Whois data provides information on when Expired Domains can be taken over
  • Contact possibilities for partnerships can be found with whois data
  • Check whether a domain has already been assigned
  • Resolution of IP addresses into URLs (IP lookup) to identify webpages that access your website

Whois queries are therefore used to check other website owners before engaging in link exchange and to check that potential partners are respectable websites.

A whois query is not always successful because the data can be obscured by different services.

It is also often assumed that search engines such as Google also launch whois queries to identify spammers. Moreover, backlinks from a website with the same whois data will have less effect than backlinks from different domains with different Admin-Cs or owners.

Consequently, it is repeatedly discussed in SEO circles whether or not the whois data is a ranking factor. It can be assumed that the data recorded there will certainly be read by Google. However, the type of data and the telephone number to be found there will have no influence on the ranking of a page. However, assuming that Google’s algorithms or Quality Raters mark certain Admin Cs or registrants as spammers, the whois data would be an indicator that a backlink from such a page should also be interpreted as spam. Thus, the whois data provides evidence for Bad Neighborhood, but not just for Google and other search engines.