Reverse DNS (PTR) Lookup

Find the hostname an IP address resolves back to. Enter an IPv4 or IPv6 address and the tool builds the reverse-pointer name, queries its PTR record over secure DNS, and shows the hostname or tells you no PTR is set. Useful for checking mail-server reverse DNS and identifying the owner of an address. Live and private in your browser.

Read the guide: What Is Reverse DNS
Enter an IP address to find the PTR record — the hostname it resolves back to.

How it works

  1. 1

    Enter the IP address

    Type an IPv4 address like 8.8.8.8 or an IPv6 address like 2001:4860:4860::8888.

  2. 2

    Look it up

    Press Look up or hit Enter. The tool converts the IP to its in-addr.arpa or ip6.arpa pointer and queries the PTR record.

  3. 3

    Read the hostname

    See the hostname the address resolves back to, or a clear note when no PTR record exists.

Instant & 100% private — nothing is uploaded

Everything runs locally in your browser. Your code, text and files are processed on your own device and are never sent to a server — so there are no upload waits, no size limits from us, and nothing is ever stored or logged.

Frequently asked questions

What is a PTR record?
A PTR (pointer) record maps an IP address back to a hostname, the reverse of the usual name-to-address lookup. It lives under a special reverse zone: in-addr.arpa for IPv4 and ip6.arpa for IPv6. Reverse DNS is set by whoever controls the IP block, which is typically your hosting provider or ISP, not the domain owner.
Why does an IP have no reverse DNS?
Many addresses simply have no PTR record set, which is normal and not an error. Reverse DNS matters most for mail servers, where a missing or mismatched PTR is a common reason mail gets rejected. Home and many cloud addresses often have either no PTR or a generic provider-assigned name.
Can an IP resolve to more than one hostname?
Yes. An address can have multiple PTR records, though it is uncommon and some receivers handle it poorly. For mail in particular, a single, forward-confirmed hostname (the PTR resolves to a name whose A record points back to the same IP) is the cleanest setup.
Is the lookup private?
The query runs in your browser against a public DNS resolver over a secure connection and reads only the PTR record. We do not store the address you enter.

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