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IPOK

Reverse DNS (PTR) Lookup

IPOK dev tools provide fast network diagnostics and data conversions, including IP purity, subnet risk, DNSBL blacklist, and ASN routing lookups.

Forward DNS maps a domain to an IP; reverse DNS (PTR) maps an IP back to a hostname. This tool builds the in-addr.arpa (IPv4) or ip6.arpa (IPv6) name automatically and looks up its PTR live.

PTR helps identify datacenter networks, trace mail servers, and investigate abuse. Your browser sends the query directly to Cloudflare DoH; it does not pass through IPOK, but Cloudflare processes it.

Reverse DNS (PTR) resolves an IP back to a hostname. Your browser contacts Cloudflare 1.1.1.1 DoH directly; the query does not pass through IPOK, but Cloudflare processes it.

Check this IP's purity — datacenter or residential →
Check your own IP — purity, risk score, native vs datacenter, leaksCheck IP →

FAQ

What is a PTR record?

It reverse-resolves an IP back to a hostname — the inverse of a forward A record — commonly used for mail anti-spam checks and tracing.

Why do some IPs have no PTR?

Many residential / ordinary IPs have no PTR configured, which is normal; datacenters and mail servers usually do. No PTR doesn't mean the IP is bad.

Can PTR tell if it's a datacenter IP?

Often yes — a datacenter PTR usually contains a cloud provider's domain. For a precise datacenter/residential verdict, use this site's IP check.

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