Look up the PTR (reverse DNS) record of any IPv4 or IPv6 address. PTR records map IPs back to hostnames.
Enter an IP address above to look up its PTR (reverse DNS) record
PTR (pointer) records implement reverse DNS - they map an IP address back to a hostname. Reverse DNS is used by mail servers to verify that the sending IP matches the claimed hostname (a common spam check), by network monitoring tools to label IPs with meaningful names, and by traceroute to display hop hostnames. PTR records must be configured by the IP address owner (usually the ISP or hosting provider), not the domain registrar - which is why many IPs have no PTR record.
IPv4 PTR queries use the .in-addr.arpa zone. The IP is reversed (e.g. 8.8.8.8 → 8.8.8.8.in-addr.arpa) and queried as a standard DNS record.
Sent to our server: IP Address. We look it up in DNS. Part of this work runs on our own server. To answer a repeated check fast, we have to keep answers for 5 minutes; then they are deleted. Also added to the page link, so you can share the result: IP Address.