Data Sources & Methodology

MaxMind GeoLite2 is the foundation of our database. It provides three CSV datasets:

• GeoLite2-Country-CSV — Maps every allocated IPv4 CIDR block to its country. This is our authoritative source for "is this IP allocated or not" and "which country does it belong to." ~580K rows covering 3.69 billion IPs.
• GeoLite2-City-CSV — Finer-grained blocks mapped to city, region, postal code, latitude/longitude, and accuracy radius. ~2.8M rows. City-level accuracy varies by region: excellent in North America and Europe, approximate in other regions.
• GeoLite2-ASN-CSV — Maps IP blocks to Autonomous System Numbers (ASNs) and organization names. ~650K rows covering 3.1 billion IPs.

MaxMind publishes fresh data every Tuesday at 00:00 UTC. Our automated pipeline downloads, validates, and imports the new data by 04:00 UTC the same day.

License: Creative Commons Attribution-ShareAlike 4.0. This product includes GeoLite2 data created by MaxMind, available from https://www.maxmind.com.

The five Regional Internet Registries maintain public statistics files showing how IP address space is distributed:

• ARIN — North America
• RIPE NCC — Europe, Middle East, Central Asia
• APNIC — Asia-Pacific
• LACNIC — Latin America, Caribbean
• AfriNIC — Africa

We use these files to infer which RIR manages each address block and to cross-validate MaxMind's country assignments.

Reverse DNS (PTR records) are queried in real-time when you visit an IP page. These lookups are performed live against the DNS system — they are not cached or pre-computed. This provides the most current hostname mapping for any IP.

Our import pipeline runs in three passes:

1. Country + city blocks — Each MaxMind CSV row becomes a row in tuxxin_ip_ranges with a data_source tag. A unique index on (ip_start, ip_end, data_source) ensures no duplicates.
2. ASN merge — ASN data is overlaid onto the same ranges using the ASN CSV's block boundaries.
3. Organization + RIR inference — Organizations are materialized from ASN names. RIR tags are inferred from IANA's /8 allocation registry. Aggregate counts (IPs per country, per ASN, per org) are recomputed.

The entire process takes ~5 minutes and runs as a single transaction with automatic rollback on failure.

We download and parse the official delegation statistics files from all five Regional Internet Registries weekly:

• ARIN — North America
• RIPE NCC — Europe, Middle East, Central Asia
• APNIC — Asia-Pacific
• LACNIC — Latin America, Caribbean
• AfriNIC — Africa

These files provide authoritative RIR assignments, allocation dates, and country codes for IP blocks that MaxMind may not cover (e.g., non-BGP-announced allocations). RIR data backfills gaps without overwriting MaxMind's more granular geolocation.

WorldIP.io operates a continuous PTR record scanner that resolves reverse DNS hostnames for all allocated IPv4 addresses. This data powers our PTR search feature and enriches individual IP pages.

• Method — Standard DNS PTR queries against authoritative nameservers for .in-addr.arpa zones. No ports are scanned; no connections are made to the target IPs themselves.
• Rate — Queries are rate-limited per authoritative nameserver to avoid overloading any single DNS operator.
• Freshness — Records are re-scanned when their DNS TTL expires, ensuring hostnames stay current.
• Coverage — Full IPv4 address space (~3.69 billion allocated IPs), with continuous re-scanning.

PTR data is public DNS information, freely queryable by any recursive resolver. Our scanner simply aggregates and indexes it for search.

• Geolocation accuracy — MaxMind GeoLite2 is less accurate than the paid GeoIP2 product. City-level accuracy is ~60-80% depending on region. Country-level accuracy is ~99%.
• Organization names — Names reflect the original allocation recipient, not necessarily the current operator. IP transfers and acquisitions may not be reflected.
• IPv6 — WorldIP.io currently covers IPv4 only. IPv6 support is on the roadmap.
• Mobile IPs — Mobile carrier IPs often geolocate to the carrier's gateway location, not the user's actual location.