FernTool

IP address lookup

Check whether an IPv4 or IPv6 address is valid and see its type and location.


Result

✓ Valid IPv4 address (public)

Country
United States (US)
Hostname
dns9.quad9.net
Network
QUAD9-AS-1
ASN
AS19281
Timezone
America/New_York (country spans 29 zones)
Type
Public DNS resolver / datacenter (Quad9): infrastructure, not a home connection

WHOIS · Reverse DNS

JSON
{
  "valid": true,
  "version": 4,
  "ip": "9.9.9.9",
  "scope": "public",
  "source": "dbip-lite+iptoasn",
  "geo": {
    "country": "US",
    "country_name": "United States",
    "asn": 19281,
    "isp": "QUAD9-AS-1",
    "timezone": "America/New_York",
    "timezones": [
      "America/New_York",
      "America/Detroit",
      "America/Kentucky/Louisville",
      "America/Kentucky/Monticello",
      "America/Indiana/Indianapolis",
      "America/Indiana/Vincennes",
      "America/Indiana/Winamac",
      "America/Indiana/Marengo",
      "America/Indiana/Petersburg",
      "America/Indiana/Vevay",
      "America/Chicago",
      "America/Indiana/Tell_City",
      "America/Indiana/Knox",
      "America/Menominee",
      "America/North_Dakota/Center",
      "America/North_Dakota/New_Salem",
      "America/North_Dakota/Beulah",
      "America/Denver",
      "America/Boise",
      "America/Phoenix",
      "America/Los_Angeles",
      "America/Anchorage",
      "America/Juneau",
      "America/Sitka",
      "America/Metlakatla",
      "America/Yakutat",
      "America/Nome",
      "America/Adak",
      "Pacific/Honolulu"
    ]
  },
  "flags": {
    "is_tor": false,
    "is_datacenter": true,
    "provider": "Quad9 (public DNS resolver)",
    "is_public_dns": true,
    "flags_updated": "2026-10-16"
  },
  "attribution": {
    "geo": "IP Geolocation by DB-IP (https://db-ip.com), CC BY 4.0",
    "asn": "ASN data from IPtoASN (https://iptoasn.com), PDDL"
  },
  "hostname": "dns9.quad9.net"
}

What does this check?

We validate the address format (IPv4 dotted decimal, IPv6 including compressed and IPv4-mapped forms) and classify it as public, private (RFC 1918 / ULA), loopback, link-local, CGNAT, multicast or reserved. API: GET /api/ip/{ip}.

VPN, Tor and datacenter detection

Every lookup checks the address against the current Tor exit-node list from the Tor Project and the published IP ranges of the big cloud providers (AWS, Google Cloud, Azure, Cloudflare, DigitalOcean and Oracle), plus well-known hosting networks such as Hetzner, OVHcloud, Linode, Vultr and M247. Most commercial VPNs and proxies run on these networks, so a “datacenter” result usually means the visitor is using a VPN, proxy or server rather than a home connection. Lists are refreshed regularly. API: POST /api/batch checks up to 100 IPs at once.

For public addresses we show the country the IP is registered to, its main timezone and the network (ASN) that announces it. Country-level IP location is right most of the time, but VPNs, mobile networks and corporate networks can make it misleading. Your own IP is resolved live from Cloudflare’s edge, including city.

Related

IP Geolocation by DB-IP (CC BY 4.0) · ASN data by IPtoASN