IP to Hostname

Reverse DNS lookup for IPv4 and IPv6 addresses.

IP to Hostname (Reverse DNS Lookup)

Find the hostname behind an IP address. Enter an IPv4 address such as 8.8.8.8 or an IPv6 address such as 2606:4700:4700::1111 and the tool performs a reverse DNS (PTR) lookup, returning the name configured by the network that owns the address.

How reverse DNS works

Forward DNS maps names to addresses; reverse DNS does the opposite using a special domain. An IPv4 address is reversed and placed under in-addr.arpa — 8.8.4.4 becomes 4.4.8.8.in-addr.arpa — and the resolver asks for its PTR record. IPv6 uses ip6.arpa with every hexadecimal nibble reversed. The PTR record is managed by whoever was delegated the address block, typically a hosting company, cloud provider or ISP, not the owner of the website.

Common uses

  • E-mail deliverability: mail servers without a matching PTR record are often rejected or marked as spam. Check that your outgoing mail IP resolves to your mail hostname.
  • Log analysis: turn raw IPs from web or firewall logs into readable names such as crawl-66-249-66-1.googlebot.com.
  • Bot verification: confirm that a visitor claiming to be Googlebot or Bingbot really comes from the search engine's network (then resolve the hostname forward to double-check).
  • Network inventory: identify routers and servers that follow a naming convention.

Tips

If no record is found, ask your provider to set a PTR record — most VPS control panels have a "reverse DNS" field. To go from a name to an address instead, use Hostname to IP. For notation conversions, see the Decimal to IP converter.

Frequently Asked Questions

Reverse DNS is optional. A PTR record only exists if the owner of the IP block (usually the hosting provider or ISP) created one. Many cloud and home addresses have none or only a generic name.

No. Whoever controls the reverse zone can put any name in a PTR record. For a trustworthy check, resolve the returned hostname forward again (forward-confirmed reverse DNS) and confirm that it points back to the same IP.

Yes. IPv6 addresses are expanded and converted to their nibble-reversed ip6.arpa name automatically, so you can paste compressed notation like 2001:4860:4860::8888.