Start by classifying the address
A lookup begins with an IPv4 or IPv6 string, but the first useful result is its scope. A globally routed public address can have registration and routing context. Private, loopback, link-local, multicast, and documentation ranges have defined special purposes and should not be sent through the same geolocation story.
For example, 192.0.2.10 belongs to a block reserved for documentation. A trustworthy tool should label that purpose instead of returning a city copied from an unrelated record. Likewise, a private Wi-Fi address may be meaningful on your network but has no unique public owner or location.
Registration data and routing data answer different questions
Internet number registries record how address resources are allocated or assigned through a hierarchy. Routing systems show which autonomous systems announce prefixes and how networks exchange reachability. A lookup provider combines this information into labels such as organization, network, prefix, and autonomous system number (ASN).
The registered organization and the network currently announcing a prefix can differ because of hosting, transit, customer assignments, acquisitions, or operational arrangements. Treat labels as network context, not a verified statement about the person using the address.
Continue with Why is my IP location wrong?, compare it with What is an IP address?, or use IP Finder for Android for the next practical step.
What ISP, ASN, prefix, and hostname mean
- Network organization or ISP
- A label associated with the address block or network service; it may be a carrier, cloud provider, VPN, enterprise, or another operator.
- ASN
- A number identifying an autonomous routing domain that announces prefixes under a common policy.
- Prefix
- A block of addresses routed or managed together, expressed with a prefix length.
- Reverse-DNS hostname
- A name the address owner may publish for the IP; it is optional and can be generic or outdated.
None of these fields is a subscriber directory. An ASN is not an account number, and a hostname is not proof that the named service is running on the device.
The protocol details in this guide follow IANA — Number Resources and Geolocation in the RIPE Database; use those primary specifications when you need exact terminology or edge-case behavior.
How approximate geolocation is produced
Geolocation databases infer country, region, city, or coordinates from registration data, routing observations, provider input, measurements, and other signals. Methods and update schedules differ by vendor. The displayed point can represent an ISP gateway, a mobile network hub, a corporate exit, or a default point for an address block.
Confidence usually becomes weaker as the claim becomes more precise. A country association may be useful even when a city or coordinate is wrong. Interfaces should label the result approximate and avoid presenting the map point as the physical location of a device.
Why two lookup services can disagree
- Check the address and time
Dynamic and VPN addresses can change; make sure both services received the same value during the comparison.
- Compare the network fields
Organization, ASN, and prefix may agree even when the city differs.
- Look for a recent network change
Reassignment, new routing, or a changed VPN exit can reach one database before another.
- Use the coarsest supported conclusion
Prefer network and country context over an unsupported exact-city claim.
What a public lookup cannot reveal
- A person’s verified identity or home address.
- An exact GPS or device position.
- Which device used a shared public address without provider records and additional context.
- A complete browsing history or list of nearby devices.
- Whether traffic is encrypted, safe, or anonymous.