• by Rob Garner , January 16, 2008

For the last seven years, there is one vertical search engine that I've used that often exceeds my use of Google and the other major engines.   DomainTools.com (formerly Whois Source), is a vertical search engine for domains, and contains a ton of useful data for search engine marketers, IT professionals, domainers, and marketers who are looking for a centralized search information around a particular domain, live Web site or existing company.   It is owned and operated by Jay Westerdal, who also produces the Domain Roundtable conference, and writes a widely-read  blog covering important issues in the domain and search worlds.

Among the engine's features, it includes:

-          Historic whois data: View current whois data, or search previous domain registrants from about six to seven years ago.  This feature is sort of like archive.org for whois data.

-          Number of DMOZ listings:  Westerdal runs a version of the DMOZ directory at DomainTools.com, and he pulls this data into the domain whois record.

-          Number of Yahoo listings:  Yahoo! directory listings are also pulled into the whois record.

-          Reverse IP: Shows all the domains hosted on a particular server.

-          Server type:  A quick shot of the server type is also provided at the domain level.

-          Bulk whois look-ups against multiple Top Level Domains (TLDs): With a basic subscription, you can view up to 600 domains at one time (100 names times six TLDs), including .com, .net, .org, .us, .info, and .us

-          Domain status: A bulk search shows whether a domain is currently available (never registered), available (previously registered), registered with active Web site, registered with no Web site, registered and parked or redirected, on hold, on hold in redemption period, or on hold pending delete. 

-          Wikipedia cross reference:  Shows the number of times a domain is referenced in Wikipedia.

-          IP address and location:  Shows IP address and geographic location data.

-          Domain suggestion tool: If you are looking for ideas for available names around a particular keyword, you never know what you might find.

-          Screen shots of names taken with existing Web sites: A screen cap is provided for individual whois record pages, and in the bulk whois feature, you can mouse over "active Web site" icons to view a small pop up image of the site.

-          Compete and Alexa rank: If you use this data, it is available as well.

-          Domains for sale feature:  DomainTools.com also features a link to domains on the secondary market that are available through Sedo or AfterNIC.

-          All of the other basic whois info: Name servers, registrar, original registration creation date, expiration date, name, address, admin, tech and billing contacts are all there.

There is also a backlink feature, but the link counts are extremely low, and it would be nice if this data was pulled in from Site Explorer.  The specific criteria used to calculate the SEO score is uncertain, though the text cache mockup of a page can be very helpful in quickly determining if a site is fundamentally text-friendly, or not.

The most controversial feature at DomainTools.com is the Registrant Search function, which will provide a list of all domains owned by a particular entity.  This is a fee-based search report that will provide a list of domains currently registered, regardless of where the domains are hosted.  It has caused many domain registrants and portfolio owners to begin using proxy services for shielding Whois data from the public view.

One thing I would really like to see from DomainTools.com is an opt-out feature for domain registrants, so that they would have more control in the way their data is shown.  The major search engines all obey robots.txt, and if DomainTools.com would adopt a similar opt-out or disallow approach to their data, it would still remain useful, but also be considerate of domain registrants concerns, especially as DomainTools.com continues to rise as a unique and powerful source of data.  If you are into the daily grind of researching Web sites and domains on a regular basis, then DomainTools.com is an indispensible vertical search engine you need to check out.

View a sample whois record for Google.com here.