Reverse IP and reverse DNS lookup
Turn an IP address back into a hostname. The reverse DNS (PTR) record is what mail servers and log analyzers use to put a name to an address; we query it live through two public resolvers and check whether the name points back to the same address.
PTR query
52.216.73.216.in-addr.arpa
| Resolver | Status | Record | TTL | DNSSEC | Latency |
|---|---|---|---|---|---|
| Cloudflare 1.1.1.1 (DoH) | NXDOMAIN | — | — | Yes | 4 ms |
| Google 8.8.8.8 (DoH) | NXDOMAIN | — | — | Yes | 7 ms |
Domains hosted on this address
Websites whose DNS points at this address, from the IP2WHOIS hosted-domain index. We show a sample of names, never the full list.
Today’s quota for the hosted-domain index is used up; only cached results are shown. Try again after Oct 23, 2026, 12:00 AM UTC.
Data attribution Hosted-domain data by IP2WHOIS (IP2Location.io)
IP2WHOIS Hosted Domain API (IP2Location.io) · not queried: daily budget reserve reached; resets 2026-10-23T00:00:00ZRun a reverse lookup
Enter an IPv4 or IPv6 address and press Look up. Your own address is pre-filled. The result shows the PTR name(s), the resolver that answered and whether forward confirmation succeeded.
Reverse DNS (PTR) result
The PTR record is set by whoever controls the address block — your ISP, the hosting provider — not by the owner of a domain.
PTR record
The hostname registered for the address in the reverse zone, for example mail.example.com for a mail server or 203-0-113-42.dynamic.example-isp.net for a consumer line. Some addresses have several.
Forward-confirmed reverse DNS
We look up the PTR name's A/AAAA records and check that the original address is among them. A match (FCrDNS) is what mail servers want to see from a sending server; a mismatch is a common reason for rejected mail.
in-addr.arpa and ip6.arpa
Reverse records live in special zones: 42.113.0.203.in-addr.arpa for an IPv4 address written backwards, and a 32-nibble name under ip6.arpa for IPv6. The block holder delegates these zones and sets the records.
Why some IPs have no PTR
Many providers never set PTRs for consumer or mobile ranges, and cloud providers leave them empty until the customer sets one. No PTR is normal for a home connection and a problem only for a server that sends mail.
Domains on this IP
Finding all websites hosted on an address (reverse IP hosting lookup) needs a passive-DNS database that records which names have resolved to the address over time; a PTR record only holds the name the operator chose. We do not have that data at launch and will add the feature when we can source it under terms that allow display. For a single site, the find a website's IP tool does the forward lookup.
How reverse DNS works
A reverse lookup is an ordinary DNS query for a PTR record in the in-addr.arpa or ip6.arpa tree. The regional registry delegates the reverse zone for a block to its holder, who runs nameservers for it and adds a record per address. Because the holder decides the content, a PTR is a statement by the network operator, not proof of anything — which is why forward confirmation matters.
Frequently asked questions
What is a reverse IP?
A lookup that starts from an address instead of a name: either the PTR record (what this page shows) or, in hosting contexts, the list of domains hosted on the address.
How do I reverse search an IP address?
Enter the address above; the PTR hostname is returned within a second. From a terminal: nslookup 203.0.113.42 or dig -x 203.0.113.42.
How to run a reverse lookup?
On this page, enter the address. On the command line use dig -x <ip> or nslookup <ip>, or host <ip> on macOS/Linux.
Can I look up who an IP address belongs to?
The PTR name often reveals the provider and sometimes the city or connection type; the registry record (see WHOIS lookup) shows the organization holding the block. The individual subscriber is never published.
Can you find the hostname from IP?
Only if the operator set a PTR record. Servers and many fixed-line addresses have one; mobile and many consumer ranges do not.
Is it possible to track someone's IP?
You can look up an address's public information — provider, area, hostname — exactly as this site does. Tracking a person from an address requires the provider's subscriber records, available only to authorities.
DNS answers from Cloudflare 1.1.1.1 and Google 8.8.8.8 (DNS over HTTPS) via the CheckMyIP lookup service; nothing is cached longer than the record's TTL (60 s on our side).