Reverse DNS (PTR) Lookup
Resolve an IPv4 or IPv6 address back to its PTR record. Useful for mail deliverability and sanity-checking what a remote IP claims to be.
Look up a reverse DNS (PTR) record
Resolves an IPv4 or IPv6 address to its PTR record via DNS-over-HTTPS. Runs entirely in your browser.
Why PTR records matter
- Mail deliverability — most receivers reject or tarpit mail from IPs with no PTR, or whose PTR doesn’t match HELO/EHLO. Set one on every server that sends mail.
- Logs that make sense — PTR records turn
93.184.216.34intoexample.com.edgesuite.netin access logs. - Forensics — when investigating unknown traffic, PTR is the first thing you look at.
How the lookup works
IPv4 addresses are queried in the in-addr.arpa zone with reversed octets —
8.8.8.8 becomes 8.8.8.8.in-addr.arpa. IPv6 uses the ip6.arpa zone with
the address expanded to 32 hex nibbles in reverse order.
Privacy
Queries go straight from your browser to Google Public DNS over HTTPS. This site never sees the lookup.