How IP Lookup and Geolocation works
IP geolocation estimates where an internet-connected device is located from its IP address alone. It powers content localization, fraud checks, analytics dashboards and "this login came from a new location" emails. It's also widely misunderstood: an IP address points to a network, not a person, and the location attached to it is an estimate. This guide explains how geolocation works and how far you can trust it.
IPv4 and IPv6 in one minute
- IPv4 addresses look like
203.0.113.42: four numbers from 0 to 255, about 4.3 billion addresses in total. - IPv6 addresses look like
2001:db8:85a3::8a2e:370:7334, with a vastly larger address space. - Private ranges are reused inside local networks and never appear on the public internet:
10.0.0.0/8,172.16.0.0/12,192.168.0.0/16andfc00::/7. Looking up192.168.1.10returns nothing useful, because thousands of homes use that same address.
Where the location data comes from
No single authoritative database maps IP addresses to places. Geolocation providers combine several sources:
- Regional Internet Registries (ARIN, RIPE NCC, APNIC, LACNIC, AFRINIC) record which organization each block of addresses is assigned to, and its registered country.
- Network routing data, such as BGP announcements and the autonomous system number (ASN) of the network that routes a block, often reveals the ISP and region.
- ISP and hosting company data, including published location feeds (RFC 8805 geofeeds).
- Measurements and signals, such as network latency from known points, Wi-Fi and GPS data from apps that collect it with consent, and user-submitted corrections.
Each provider weighs these differently, which is why two services can disagree about the same address.
How accurate is it?
| Level | Typical accuracy |
|---|---|
| Country | Usually correct for fixed broadband |
| Region / state | Often correct, sometimes off |
| City | Frequently wrong by tens of miles |
| Street address | Not possible from an IP address |
Accuracy drops sharply in these cases:
- Mobile networks route traffic through a few central gateways, so a phone in one city can appear hundreds of miles away.
- VPNs, proxies and privacy relays (such as iCloud Private Relay) show the location of the exit server, by design.
- Corporate networks often send all employees' traffic out through headquarters.
- Cloud and hosting providers host addresses that belong to a data center, not a user.
- Reassigned blocks. Address blocks move between organizations and countries, and databases take time to catch up.
When a lookup shows a "default" location such as the geographic center of a country, it means the provider only knows the country.
What else a lookup tells you
Beyond location, a lookup typically returns the ISP or organization, the ASN, and the time zone. Network details are usually more reliable than the city. Knowing that traffic comes from a cloud provider's ASN rather than a residential ISP is a strong signal for bot detection.
Using geolocation responsibly
- Treat it as a hint. Use it to pick a default language or currency, then let the user change it.
- Don't block or accuse based on location alone. Combine it with other signals for fraud decisions, and expect false positives from travelers and VPN users.
- Mind privacy law. IP addresses are personal data under the GDPR. Store them only as long as you need them, and say so in your privacy policy.
Try it
The IP Lookup tool shows your own public IP address, or details for any address you enter: approximate location, ISP, organization and time zone. Lookups are sent from your browser to a third-party geolocation service, so that service sees the address you look up.