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Reverse IP Lookup

Enter an IP address to list the domains known to be hosted on it.

Updated

Server processing — results come from a shared public dataset and may be incomplete for large hosts.

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Enter an IP address and run a lookup to see co-hosted domains here.

How to use Reverse IP Lookup

The Reverse IP Lookup tool finds other domains and websites that are hosted on the same IP address as the one you enter. Many sites share a single server or load balancer — especially on shared hosting and some CDNs — so a single IP can front dozens or hundreds of unrelated domains. Discovering those neighbours is useful for security research, for understanding how an organization’s infrastructure is laid out, and for spotting sites that may be affected by the same server-level problem. Results are drawn from a large passive dataset, so the lookup never probes the target server directly.

  1. Enter the IPv4 address you want to investigate.
  2. Click Lookup to query the reverse-IP dataset.
  3. Review the list of domains reported on that address.
  4. Note the total count to gauge how crowded the server is.
  5. Cross-check interesting domains with WHOIS or DNS tools.

Why many domains share one IP

Shared hosting plans place many customers on a single server to keep costs low, and the web server uses the HTTP Host header (or TLS SNI) to decide which site to serve for each request. CDNs and reverse proxies take this further, fronting thousands of origins behind a small pool of edge IPs. As a result, a reverse IP lookup on a shared or CDN address can return a long list of unrelated domains, while a dedicated server or a site on its own IP may return only one or two.

Limits of reverse IP data

Reverse IP results come from a passive dataset built by crawling and DNS observation, not from the server itself, so they are a strong sample rather than a guaranteed complete list. Large CDNs such as Cloudflare or Fastly share edge IPs across enormous numbers of sites, so a lookup there reflects the CDN rather than a single owner. Treat the output as a research lead and confirm relationships with WHOIS, certificate transparency, or DNS records before drawing conclusions.

Typical hosting scenarios
ScenarioReverse IP result
Dedicated serverOne or a few related domains
Shared hostingMany unrelated domains
CDN edge IPSites belonging to the CDN, not one owner

Glossary

Reverse IP
Finding the domains that resolve to a given IP address.
Shared hosting
A plan where many websites run on one server and IP address.
Host header
The HTTP header a server uses to pick which site to serve on a shared IP.
SNI
Server Name Indication — the TLS field that selects a site on a shared IP.
CDN
Content Delivery Network that fronts many origins behind shared edge IPs.

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