Reverse NS API finds all domains linked to a nameserver | WhoisXML API

Reverse NS API lists all domain names that use a specific nameserver

Reverse NS API lets you see the list of domain names tied to the same nameserver via API calls with outputs in JSON and XML.

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500 free API credits. No credit card required.

1,4B+Domains and subdomains
196,463,291NS records updated daily
2,131Satisfied customers

What is Reverse NS API?

A reverse NS API is a data consumption model that returns a list of domains connected to a nameserver used as an input. It can help understand if a nameserver is dedicated to a single individual or organization or if it is shared among several hosts.

Reverse NS API


  • Exhaustive and relevant

    All of the historical DNS API results come from a massive database that is updated daily. The database contains 500 billion historical lookup records, including more than 196 million nameserver records.

  • Easy to integrate

    There is no need to worry about compatibility issues with reverse NS API. Our nameserver records come in well-known and widely used formats, including XML and JSON.

Practical usage

Increase your website availability

Increase your website availability

You may not be able to reach your target audience when you share nameservers with domains that are involved in malicious activities. Avoid getting blacklisted by using Reverse NS API to see what domains you share nameservers with.

Go ahead with regular security checks

  • Trace domain associations you didn’t know existed.
  • Perform research on suspicious nameservers.
  • Protect your website from defacement.
Go ahead with regular security checks
DNS Database Download

A massive passive DNS database at your fingertips

Our passive DNS database is easily one of the world's largest with more than 500 billion historical DNS records, 2 billion hostnames, and over 196 million nameserver records.

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Reverse NS API | WhoisXML API

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Enterprise API Packages

Want to allocate resources better across all our APIs? Our various annual subscription packages are advantageous if you are looking for multiple sources of domain and IP intelligence with the best value.

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