IP Address Lookup

Accuracy varies by location and data source: Country level: 95-99% accurate (very reliable). State/Region: 80-90% accurate in US/Europe, lower in other regions. City: 50-75% accurate depending on population density - accurate in cities, unreliable in rural areas. Coordinates: accurate within 25-100 miles typically, not precise enough for street-level. Why inaccurate: IPs may be registered to ISP HQ location (not user location), mobile IPs change location as users move, VPN/proxy IPs show VPN server location, corporate networks may route through central office. Never use IP geolocation for critical decisions like legal jurisdiction or precise user targeting.

Public IPs are globally unique addresses reachable on internet, assigned by ISPs, visible to websites you visit, used for lookups/geolocation. Ranges: any IP except private ranges. Private IPs are local addresses used within networks (LANs), not routable on internet, reusable across different networks, hidden behind NAT router. Ranges: 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16. Example: your device has private IP (192.168.1.100 on home network), router has public IP (203.0.113.50 visible to internet). Tools show public IP only - private IPs are not visible to external services. Your router translates (NAT) between private internal IPs and single public external IP.

Common reasons: ISP registered IP block to headquarters location (not your actual location), using mobile data (IP may show nearest cell tower or regional routing center), behind corporate VPN (shows company office location, not home), using proxy/VPN service (shows VPN server location), ISP uses dynamic IP pool covering large region (IP assigned from pool that serves multiple cities), IP database outdated (IPs reassigned but database not updated). This is normal - geolocation databases use IP registration data and network topology, not GPS. If consistently wrong, can request ISP to update their IP registration. Most services use IP for approximate region only (time zone, language, currency), not precise location.

Yes, but with important caveats: Effectiveness: blocks majority of users from target country (80-90%), but not foolproof. Easy bypass: VPNs, proxies, Tor make IP blocking ineffective against determined users. False positives: blocks legitimate users traveling abroad, expats, remote workers, VPN users from allowed countries. Legal considerations: some countries require geoblocking for licensing (content rights), GDPR applies to EU residents regardless of IP location. Better alternatives: combine IP check with other signals (browser language, billing address, payment method country), use challenge-response for suspicious IPs (CAPTCHA), implement rate limiting instead of hard blocks. Use IP geoblocking for compliance requirements, not security.

VPN/proxy changes apparent IP location to VPN server location. User in New York using London VPN shows London IP with UK geolocation - all websites see UK location, ISP shows VPN provider (NordVPN, ExpressVPN) not home ISP, timezone may mismatch user's actual timezone. Detection: check if IP belongs to known VPN/proxy provider (blacklists available), look for datacenter IPs vs residential IPs (VPNs typically use datacenter IPs), detect IP/timezone mismatches, analyze connection patterns (many users from single IP suggests VPN). Why use VPN: privacy, bypass geo-restrictions, avoid censorship, secure public WiFi. Legitimate uses mean blocking all VPNs is not recommended - use for fraud detection signals only.

IPv6 geolocation is generally less accurate than IPv4 currently (2026) but improving. Challenges: IPv6 allocations are newer (less historical data), addresses often auto-assigned via SLAAC (privacy extensions create rotating addresses), many ISPs assign large IPv6 blocks to regions not specific locations, geolocation databases have less comprehensive IPv6 data. Accuracy: Country-level is good (85-95%), city-level often less accurate than IPv4 (40-60%). Improving with time as more IPv6 data collected. Best practice: detect both IPv4 and IPv6, prefer IPv4 for geolocation when available (dual-stack), do not rely on precise IPv6 geolocation, expect accuracy to improve over next 2-3 years as IPv6 adoption increases.