DNS & IP History | Multi-billion DNS records | WhoisXML API

Use DNS history to see all connections between IP addresses and hostnames

Determine the links between IP addresses and hostnames with our IP & DNS record history products powered by regularly updated data covering billions of IP and DNS records.

500 free API requests. No credit card required.

50 Billion+Domains and subdomains
Billions"A" records
Millions"A" records added weekly
52,000+Satisfied customers

Our DNS & IP history product line includes:


Just take an IP address as input to start your DNS history query. See which domain names (if any) are sharing the queried IP address in a custom report.

Reverse IP/DNS Lookup | WhoisXML API
Reverse IP/DNS API | WhoisXML API


Benefit from our reverse IP/DNS capabilities via API calls. Integration is easy with the help of our readily available client libraries.

DNS Database Download

Our DNS database is a repository of all the connections identified for the past 12 years between domains/hostnames and their A, MX, NS, TXT, CNAME, and SOA records. We offer convenient formats for easy correlation with other data sources and straightforward integration into existing products.

DNS Database Download | WhoisXML API


  • Сomprehensive

    Our Reverse IP/DNS product line gives access to most current and historical connections between IP addresses and hostnames. Our DNS database is one of the largest of its kind with billions of recorded events.

  • Convenient

    Just use an IP address to find domain names (possibly) sharing it. Users can choose the consumption model that works best for them (lookup, API, or database).

Practical usage


Get a comprehensive list of potentially harmful domains that share the IP addresses of known malicious websites. Use attackers or suspected actors’ IP addresses as reverse IP search terms to get an idea of their infrastructure or uncover yet-unidentified web properties that can cause harm.

Penetration Testing

Learn how wide your potential attack surface is with an exhaustive list of all the domains connected to each of your specific IP addresses. DNS and IP history records also let you conduct further research to learn if you share IP hosts with vulnerable websites.

SEO Ranking and Digital Marketing

Ensure you are not sharing your IP address with other domains or get the list of domain names you share your IP address with to conduct further investigation and verify their legitimacy. Sharing IP addresses with malicious domains can lead to lower search engine ranking, which can negatively affect your digital marketing efforts.

Web Reputation and Oversubscription Management

Avoid the perils of IP overcrowding. Sharing IP addresses with too many domains can slow down your website’s performance. And if one or some of them turn out to be malicious, you may land on a blacklist.

Domain Asset Management and Brand Protection

Audit all your web properties to further ensure none of them have ties to malicious domains as connections to questionable web properties can damage your brand reputation.

What is IP or DNS History?

IP history, or more broadly DNS history, is a repository of resolutions between a domain or a subdomain and its past A, MX, and NS records among others. Historical DNS records can be helpful as a part of cybersecurity investigations and network protection activities.

dns ip history

Domain Name System Primer

In this white paper, we give an overview of the Domain Name System, or DNS, one of the pillars of the Internet.

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Reverse IP/DNS Overview | WhoisXML API

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Frequently Asked Questions

  • What is the DNS and what is it for?

    The Domain Name System (DNS) is often dubbed the Internet’s phonebook. It converts domain names into IP addresses to direct you to the website you wish to visit. In a nutshell, the DNS helps us remember how to reach a website without the difficulty of memorizing IP addresses.

  • What are passive DNS records?

    Passive DNS records serve as means to keep track of historical DNS data for domain names, IP addresses, mail servers, and nameservers. For example, they can provide a list of all the IP resolutions a domain name has had over the years or give a list of all the domain resolutions an IP address has had over time.

  • Why is tracking DNS history important?

    Tracking DNS history is critical if you want to discover all the possible components of a suspicious or malicious infrastructure that may be related to a cyber attack you’re investigating. It can help you identify shared hosts that could figure in both current and past attacks, possibly meaning that you are dealing with the same set of threat actors.

  • What are historical DNS records used for?

    Historical DNS records are very useful in cybersecurity investigations, particularly in expanding lists of indicators of compromise (IoCs) and identifying new artifacts. Given a single domain or IP address, you can perform a passive DNS data lookup to find other related web properties. They are also handy when determining the components of a criminal infrastructure.