IP Geolocation: How Accurate Is It Really?
Explore how IP geolocation works, its accuracy limitations, and why your IP might place you in the wrong city.
How IP Geolocation Works
IP geolocation is the process of mapping an IP address to a real-world geographic location. When you visit a website and it knows your approximate city, it is using IP geolocation data behind the scenes.
Geolocation databases are maintained by companies like MaxMind, IP2Location, and DB-IP. They build their datasets from several sources:
- Regional Internet Registry (RIR) records — ARIN, RIPE, APNIC, LACNIC, and AFRINIC publish which organizations hold IP blocks and their registered addresses.
- ISP data partnerships — Internet providers share which IP ranges serve specific geographic areas.
- User-contributed data — Wi-Fi positioning, GPS-tagged pings, and opt-in location signals refine city-level accuracy.
- Latency-based triangulation — Measuring round-trip times from known probe servers to estimate physical distance.
Accuracy by Granularity
Geolocation accuracy drops dramatically as you zoom in:
| Level | Typical Accuracy |
|---|---|
| Country | 95-99% |
| Region / State | 75-90% |
| City | 50-80% |
| Postal code | 20-50% |
| Street address | Unreliable |
At the country level, geolocation is highly reliable because large IP blocks are allocated to specific countries. City-level accuracy varies widely depending on the ISP and region. Dense urban areas with many ISP points of presence tend to geolocate more accurately than rural regions.
Why Your IP Might Show the Wrong Location
Several factors cause geolocation errors:
- VPN and proxy usage — Your traffic exits from the VPN server's location, not yours.
- Mobile networks — Carriers route traffic through centralized gateways. Your phone might show a city hundreds of kilometers away.
- Carrier-grade NAT (CGNAT) — Multiple users share one public IP, and the registered location may reflect the ISP's hub, not your home.
- Stale database entries — IP blocks get reassigned, but geolocation databases may take weeks or months to update.
- Satellite internet — Providers like Starlink route traffic through ground stations that may be far from the user.
Real-World Applications
Despite its limitations, IP geolocation powers many services:
- Content localization — Showing prices in local currency, language auto-detection.
- Ad targeting — Serving region-specific advertisements.
- Fraud detection — Flagging transactions from unexpected locations.
- Compliance — Enforcing geographic content restrictions (geo-blocking).
- Analytics — Understanding where website visitors come from.
Improving Geolocation Accuracy
If you maintain a service that relies on IP geolocation:
- Use multiple databases and cross-reference results for higher confidence.
- Allow user correction — Let users set their own location as a fallback.
- Cache wisely — IP-to-location mappings change; refresh your database regularly (monthly at minimum).
- Combine signals — Use GPS, Wi-Fi positioning, or browser Geolocation API when available and permitted.
Key Takeaways
IP geolocation is a useful approximation, not a precise pinpoint. It works well for country and region detection but should never be treated as ground truth for city or street-level location. For any application where accuracy matters, always provide users a way to confirm or correct their detected location.