Reverse IP/DNS Lookup | Whois XML API

Get lists of all domains sharing an IP address with Reverse IP/DNS Lookup

A lookup query instantly generates an intuitive and shareable report with all domain names connected by an IP address for cybersecurity, marketing, and other use cases.

Reverse IP/DNS Lookup
1,473,142,430Domains and subdomains
1,227,998,076IPv4 database updated daily
2,131Satisfied customers

Why Reverse IP/DNS Lookup?

  • Backed by comprehensive data

    With a reverse IP address lookup, lists of connected domains are retrieved from the largest historic IP/DNS database built from over a decade of data crawling.

  • Outputs in a matter of seconds

    The lookup service can identify thousands of domains that share the same IP address in near real-time for immediate investigations and incident response.

  • Easy-to-interpret results

    Reverse IP/DNS Lookup’s hosted reports are made available with report URLs that can easily be shared with colleagues, clients, and other relevant stakeholders.

Practical usage



  • Sever ties to malicious activities by checking for connections between your IP addresses and dangerous domains. Keep cybersecurity risks to a minimum and reduce the potential attack surface with Reverse IP/DNS Lookup’s comprehensive outputs.
  • Make sure that none of your prospective or current suppliers, business partners, customers, or any other third parties could drag you down because of an IP connection to a malicious domain.
  • Steer clear from any domain tied to an IP address that has been linked to phishing, spamming, and other cybercriminal activities.

SEO & marketing

  • Do you share IP addresses with other parties? Make sure that none of them suffer from oversubscription with Reverse IP/DNS Lookup. Too many domains on the same IP address can slow down your site and harm your email deliverability.
  • With just their IP addresses on hand, you can analyze your competitors’ connected domain infrastructure to find out about recent site acquisitions and domain registrations that may be indicative of future business expansion.
SEO & marketing
IT planning

IT planning

  • Use Reverse IP/DNS Lookup in combination with other tools to make informed decisions about your IP/domain infrastructure.
  • You can make accurate inventories of all the sites hosted on the same IP addresses that belong to your company and decide whether to purchase new IP addresses, discard old ones, or shift domain names from one IP address to another to avoid low performance.
  • Study all recently acquired IP addresses and their connected domains following a merger, acquisition, or joint venture to make sure none of them have malicious connections that could affect your business.
  • Follow up on reports of abuse concerning IP addresses you manage and spot problematic domain names with Reverse IP/DNS Lookup.
DNS Database Download

Get access to the biggest Passive DNS Database

The passive DNS database is a large Historic DNS repository with 2 billion hostnames and hundreds of billions of Historic DNS Lookups. Our comprehensive passive DNS database allows finding out all historical DNS data points for any hostname and ip address.

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