Reverse IP Lookup
Enter an IP address to see its reverse-DNS (PTR) hostname, if one is configured.
Overview
Reverse DNS maps an IP address back to a hostname via a PTR record — the opposite direction of a normal DNS lookup. This tool queries the PTR record for an IP address directly and shows whichever hostname (or hostnames) it resolves to.
This tool reports the reverse-DNS hostname configured for the IP, not a full list of every domain hosted on that IP — that broader lookup needs an indexed third-party dataset this pilot doesn't include yet.
Examples & Sample Data
A public DNS resolver's PTR record
8.8.8.8
dns.google
How It Works
- Enter an IPv4 or IPv6 address.
- Complete the verification check if shown.
- Click Look Up to query its PTR record.
- Review the hostname returned, or a clear "not found" result if none is configured.
Common Use Cases
Identifying a server behind an IP
Check whether an IP address has a meaningful reverse-DNS hostname configured, e.g. when investigating logs.
Verifying mail server PTR configuration
Confirm an outbound mail server's IP has a matching PTR record, which many receiving servers check as part of spam filtering.
Tips & Best Practices
- Not every IP address has a PTR record configured — a "not found" result is common and not necessarily a misconfiguration, except for outbound mail servers where it usually should be set.
- A PTR record doesn't have to match any forward DNS record for the same name — the two are configured independently.
Frequently Asked Questions
No — it reports the IP's reverse-DNS (PTR) hostname only, not a full list of co-hosted domains, which would need a different, indexed data source.
This lookup makes a DNS query on your behalf, so a quick bot check helps keep the tool available and responsive for everyone.
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