Reverse NS Lookup | Whois XML API

Check which domains are sharing the same name server with Reverse NS Lookup

Reverse NS Lookup lets users retrieve domain name lists sharing a name server or hosting company for cybersecurity, marketing, and IT purposes.

Reverse NS Lookup
1,473,142,430Domains and subdomains
196,463,291NS records updated daily
2,131Satisfied customers

Why Reverse NS Lookup?

  • Exhaustive and Regularly Updated Data

    Reverse NS Lookup’s outputs are accurate, comprehensive, and backed by the world’s largest DNS record database, with close to 200 million NS records updated every day.

  • Near-Instantaneous NS Lookup Results

    Reverse NS Lookup’s reports are created in a matter of seconds and have shareable URLs for faster communication and decision-making.

Practical usage



  • Gather information about name servers that have been compromised, added on a blacklist, or used as part of a cyber attack and report the connected domain names to their registrar or hosting company.
  • After a name server was reported as an indicator of compromise (IoC), Reverse NS Lookup can list down all domains that should be monitored and possibly added to blocklists.
  • If you are interested in investigating anonymous site visitors whose domains or IP addresses are privacy-protected, but you know their name server, you can do a reverse name server lookup to get to know them better.

SEO & Marketing

  • Ensure that your domain doesn’t have a connection to a shady name server as it can land you on a blacklist and negatively impact your search engine rankings and brand reputation.
  • Use Reverse NS Lookup to see the latest domain additions to your competitors’ name server addresses to investigate future product launches and business expansions.
SEO & Marketing
IT Departments

IT Departments

  • Study your DNS infrastructure with Reverse NS Lookup to understand which of your domain names are sharing a name server and decide whether to keep or change this setup.
  • Examine third-parties’ name server addresses to gather a list of all domain name assets or to map NS connections following a merger, acquisition, or partnership.
  • Dig deeper into the domains you’re sharing name servers with to avoid bad online neighbors.
DNS Database Download

Complement name server data with the largest IP/DNS database

Uncover all historical associations between IP addresses and domains or sub-domains. Our data is well-parsed and complete with timestamps for 2 billion hostnames.

Request database
Have questions?

We are here to listen. For a quick response, please select your request type or check our Contact us page for more information. By submitting a request, you agree to our Terms of Service and Privacy Policy.

Or shoot us an email to