How to use it
- Enter an IP address in IP address: IPv4 such as 8.8.8.8, or IPv6 such as 2001:db8::1. Or press Use my IP address.
- Choose a Resolver and press Look up.
- Read the Host name. Then check Forward check: Confirmed means the host name points back to the address.
What a reverse lookup finds
A reverse lookup asks the DNS which name an address points to, the opposite of an ordinary lookup. For an IPv4 address the octets are written backwards under in-addr.arpa: 8.8.8.8 becomes 8.8.8.8.in-addr.arpa. For IPv6 the hexadecimal digits are reversed one by one under ip6.arpa, as RFC 3596 section 2.5 describes. The answer is a PTR record, which holds a host name.
- Whoever holds the address block sets this record: usually your internet provider, a cloud host or a hosting company.
- Many addresses have no PTR record, or only a generic one built from the address itself.
Forward confirmation
A PTR record can name any host, so the name alone proves little. Forward confirmation takes the host name from the PTR record, looks up its own A and AAAA records, and checks that one of them is the address you started with. Confirmed means the two records agree.
Mail servers often look for this match, although it is only one signal among others. Forward-confirmed reverse DNS is described on Wikipedia.
What this tool sends
The address shown at first is your own, taken from our server, which answers with the address your request came from and stores nothing. Nothing is sent to a resolver until you press Look up. Then only the address you chose goes to the resolver you chose, Cloudflare or Google, as DNS questions for its PTR record and for the A and AAAA records of the host name.
The resolver sees those questions and the IP address they come from, as with any DNS lookup.
Example: 8.8.8.8, the public resolver of Google
Enter 8.8.8.8. Its reverse name is 8.8.8.8.in-addr.arpa, and the PTR record of that name is dns.google. The A records of dns.google are 8.8.8.8 and 8.8.4.4. One of them is the address we started with, so the reverse record is confirmed.
The result is the answer of 2026-11-10 from Google's resolver.
| Step | Result |
|---|---|
| Reverse name | 8.8.8.8.in-addr.arpa |
| Name the address points to | dns.google |
| Addresses of that name | 8.8.8.8, 8.8.4.4 |
| Result | Confirmed |
Frequently asked questions
What is reverse DNS?
It is the lookup from an IP address to a host name, the opposite of looking up a name's address. The answer is a PTR record in the reverse zone of the address block.
Why does my own address have no host name?
Reverse records are set by whoever holds the address block, and many providers do not set them for home or mobile connections. A missing record does not mean that your connection has a fault.
What does forward-confirmed mean?
It means the host name in the PTR record resolves, through its own A or AAAA records, back to the original address. If it does not, the name cannot be relied on to describe that address.
Does this tool show my real IP address?
It shows the address your connection presents to this site, which is usually the public address your internet provider or VPN gives you. That address is not stored, and the lookup sends it to no one unless you choose to look it up.
Can one host name serve several addresses?
Yes. A host name can have several A and AAAA records, and an address can have a PTR record that names a host with other addresses as well. Forward confirmation needs only one match.
Which resolver should I choose?
For public records Cloudflare and Google return the same answers. If one does not answer, choose the other.
Sources
- RFC 3596: DNS extensions to support IP version 6 (section 2.5, ip6.arpa)
- Wikipedia: Forward-confirmed reverse DNS
- RFC 1035: Domain names, implementation and specification
- Cloudflare: DNS over HTTPS, JSON API
- Google Public DNS: DNS over HTTPS, JSON API
Figures and text last checked on Tuesday, November 10, 2026.