Reverse DNS Lookup

Find the hostname (PTR record) behind any IP address. Live DNS-over-HTTPS lookup — not a cached database, so it reflects whatever the network operator has published right now.

Enter an IP address above and press Look up.

Reverse DNS maps an IP address back to a hostname using a PTR (pointer) record — the inverse of the A/AAAA record that maps a hostname to an IP. A PTR record is set by whoever controls the IP block (the hosting provider or ISP), not the domain owner, so it often reveals infrastructure rather than a public-facing site name.

Why it matters

Mail deliverability
Most receiving mail servers check that a sending IP has a PTR record that resolves back to a hostname in a matching domain (forward-confirmed rDNS). Missing or mismatched PTR records are a common reason legitimate mail lands in spam.
Security investigation
A PTR record often names the hosting provider or cloud region directly (e.g. ec2-…amazonaws.com), a fast way to tell hosting infrastructure apart from a residential or business connection.
Log enrichment
Adding a resolved hostname to access logs or SIEM events gives an analyst more context than a bare IP, especially for infrastructure that rotates addresses but keeps a stable naming convention.

FAQ

Plenty of IPs — especially residential connections and many cloud instances — have no PTR record configured at all. The lookup returns hostname: null; that by itself is not suspicious.
Yes. IPv6 reverse lookups use the same PTR mechanism under the ip6.arpa zone instead of in-addr.arpa, handled automatically.
No — this performs one PTR lookup for one IP. It will not list every domain hosted on a given address; that is a different (and much heavier) kind of reverse-IP product.

About this tool

Reverse DNS maps an IP address back to a hostname using its PTR record. This tool performs that lookup for any IPv4 or IPv6 address and shows the hostname the address owner has published, if there is one.

How it works

The query is made live using DNS-over-HTTPS, so the answer reflects the current state of the DNS rather than a cached snapshot. The result is the exact PTR value returned, with no guessing and no stitching together of other data.

What to keep in mind

Many addresses have no PTR record at all, and the ones that do are set by whoever controls the address block, so a hostname is a hint rather than proof of identity. A PTR record that looks reassuring should be confirmed by checking that the hostname resolves forward to the same address.

Common uses

Reverse DNS is routinely used to identify mail servers, to read server logs more easily, to spot crawlers that claim a well-known name, and to troubleshoot email deliverability where receiving servers expect a matching PTR.

Related: Hosted domains lookup · IP whois lookup · ASN lookup · IP lookup