Reverse IP Lookup

Look up reverse DNS PTR records for IPv4 or IPv6 addresses through public DNS-over-HTTPS resolvers directly in the browser.

Reverse Lookup
Query the PTR record for an IPv4 or IPv6 address through a DNS-over-HTTPS resolver.

Enter a single IPv4 or IPv6 address. CIDR ranges, domains, and URLs are not accepted.

The lookup runs in your browser against the selected public DNS-over-HTTPS endpoint.

DNS Result
Reverse DNS target, resolver response, and PTR hostnames for the current address.
Ready to query
Enter an address and run the lookup. Current resolver: https://cloudflare-dns.com/dns-query

Reverse IP Lookup converts an IPv4 or IPv6 address into its reverse DNS name and queries the corresponding PTR record. It helps you check which hostname an address owner publishes for mail servers, network appliances, cloud instances, and troubleshooting notes.

What It Checks

For IPv4, the tool reverses the octets and queries an in-addr.arpa name. For IPv6, it expands the address to 32 hexadecimal nibbles, reverses them, and queries the matching ip6.arpa name. The result shows the exact reverse DNS domain, DNS status code, resolver, address family, and any returned hostnames with their TTL values.

How the Query Runs

The lookup runs from your browser using DNS-over-HTTPS. You can choose Cloudflare, Google, or AliDNS as the resolver, and the browser sends a standard PTR query to that endpoint. No server-side InBrowser.App lookup service is involved.

How to Read Missing Results

A missing PTR answer is common. Many residential, cloud, private, or newly assigned addresses do not publish reverse DNS records. A successful DNS response with no hostnames does not prove the address is unused; it only means the reverse zone did not return a usable PTR record through the selected resolver.

Practical Notes

  • Reverse DNS maps an IP address to a hostname; it is different from finding every domain hosted on the same address.
  • PTR records are controlled by the IP address owner or upstream provider, not by the domain owner alone.
  • Mail and security systems often compare forward and reverse DNS, so a PTR record should usually point to a hostname that resolves back to the same address.