IPTools UK

IP Address Lookup

Enter any IPv4 or IPv6 address to see its type, approximate location, network allocation and reverse hostname.

Accepts IPv4 (e.g. 203.0.113.10) or IPv6 (e.g. 2001:db8::1)

About this tool

This lookup combines three independent, free data sources: RDAP (for official registry allocation data), a DNS PTR query (for the reverse hostname), and the Team Cymru IP-to-ASN DNS service (for the announcing network's ASN). No paid API key is required for any of this — if a richer, city-level geolocation provider has been configured for this deployment, its result appears in the "Approximate city/region" field; otherwise that field explains that no provider is configured.

How to use this tool

  1. Enter an IPv4 address (e.g. 8.8.8.8) or IPv6 address (e.g. 2001:4860:4860::8888).
  2. Select "Look up".
  3. Review the network, RDAP and reverse DNS results. The URL updates with your query, so you can bookmark or share it.
Geolocation is approximate

IP-based location data reflects network routing, not a precise device location. Do not use it to identify a specific person or street address. Read more in our privacy notice.

Frequently asked questions

Why do I sometimes see no result for a private IP address like 192.168.x.x?
Private, loopback and other reserved address ranges (defined in RFC 1918 and related standards) are not part of the public internet, so there is no public registration, ASN or geolocation record to look up. The tool tells you which reserved category the address belongs to instead.
Why is the location only approximate?
IP geolocation is inferred from network routing and registry records, not GPS. It commonly identifies the correct country and often the ISP's regional hub, but rarely a precise address — particularly for mobile networks and VPNs.
What is RDAP?
RDAP (Registration Data Access Protocol) is the modern, structured replacement for legacy WHOIS, standardised in RFC 9082/9083. It returns machine-readable JSON directly from the relevant regional internet registry (ARIN, RIPE NCC, APNIC, LACNIC or AFRINIC).

WHOIS Lookup

Look up registration data for a domain, IPv4/IPv6 address or ASN using RDAP, the structured successor to legacy WHOIS.

Reverse DNS

Look up the PTR record for an IPv4 or IPv6 address to find its reverse hostname.

Subnet Calculator

Calculate network address, broadcast address, usable host range, subnet mask, wildcard mask and binary representation for any IPv4 subnet.