ASN lookup

ASN lookup

Find the autonomous system that announces a public IP: AS number, organization, route and usage type. Paste an IP or hostname, or use this connection. We do not publish a page per ASN or per IP.

Hostnames resolve to a public A or AAAA, then we read network.asn from that address.

Waiting for an IP or hostname. Submit to see ASN and organization.

IP locations are approximate network estimates. Queries are processed at Cloudflare's edge and full visitor IP addresses are not retained in application storage.

Look up an IP’s ASN

  1. Paste a public IPv4, IPv6 or hostname, or click “Use my IP” for this connection.
  2. Read network.asn (for example AS15169), network.organization, network.route and network.usage. Those fields describe the origin network, not a subscriber’s street.
  3. Need city, timezone or VPN flags as well? Continue on /ip-lookup. This page is for the AS question.
  4. Scripts can parse the same ipkit.v1 object: curl https://ipkit.dev/8.8.8.8 and read .network.asn. There is no HTML page per AS number.

What an ASN is (and is not)

An autonomous system is a routing policy on the public internet, identified by a number such as AS15169. Organizations obtain ASNs from a regional registry (ARIN, RIPE, APNIC, LACNIC, AFRINIC) and announce IP prefixes over BGP. “ASN lookup” in practice usually means: given an IP, which AS originates it, and under what name? It is not a company registry, not a list of every customer behind a cloud ASN, and not a way to unmask a person. One ISP may operate several ASNs; one ASN may carry traffic for many brands.

How to read AS number, organization and route

For 8.8.8.8 you should see AS15169 and Google LLC, with a route like 8.8.8.0/24 and usage hosting. That tells you the prefix is originated by Google’s AS, which matches public DNS anycast — not that a human in Mountain View issued the packet. Cloudflare’s 1.1.1.1 is AS13335. A residential broadband IP typically shows the access ISP’s ASN and a usage type such as isp or consumer. If organization and ASN disagree with what you expected, the address may sit on a transit provider, a CDN, or a VPN concentrator.

Looking up by AS number alone

This tool answers ASN from an IP (or hostname that resolves to one). We do not run a full WHOIS/RDAP ASN browser, and we will not generate thousands of thin /asn/15169 HTML pages. If you only have “AS15169”, pick a well-known address on that network (8.8.8.8 for Google) or use the IP you actually care about. For geolocation and privacy signals around the same record, use IP lookup. For whether this browser has IPv6, use the IPv6 test.

Worked ASN examples

8.8.8.8 → AS15169

8.8.8.8

ASN
AS15169
Organization
Google LLC
Route
8.8.8.0/24 (typical)
Usage
hosting

Google Public DNS. The AS number identifies Google’s routing domain. Anycast means the same prefix is announced from many places; the ASN stays Google’s.

1.1.1.1 → AS13335

1.1.1.1

ASN
AS13335
Organization
Cloudflare, Inc.
Route
1.1.1.0/24 (typical)
Usage
hosting / CDN

Cloudflare DNS and CDN infrastructure. Seeing AS13335 on a client IP often means the traffic exited a Cloudflare product or the address is anycast DNS, not a household.

FAQ

What does ASN lookup mean?

Given a public IP, return the autonomous system number and organization that announce its prefix, plus route and usage when the provider has them.

Can I look up an AS number without an IP?

Not here. Paste an IP on that network instead. We do not generate a thin page per ASN.

Is the organization the same as the ISP a person pays?

Often for residential IPs, not for cloud, CDN, university or VPN ranges. The field is the network operator of the prefix.

Does ASN lookup reveal a street address?

No. An AS covers many prefixes and locations. Use this for routing context, not identity.

Is there JSON for ASN fields?

Yes. curl https://ipkit.dev/<ip> and read network.asn, network.organization, network.route and network.usage. Schema ipkit.v1. See /docs.