Find the organization, announced prefixes and BGP neighbours of an ASN, or find which ASN owns an IP.
An Autonomous System Number (ASN) identifies a network that makes its own routing decisions on the internet, a carrier, a cloud provider, a university or a company with its own IPs. Each ASN announces one or more blocks of IP addresses (prefixes) via BGP (Border Gateway Protocol), the protocol that decides where internet traffic actually flows. This tool queries RIPEstat, RIPE NCC's public routing statistics API (which covers the whole internet, not just the RIPE region), and shows the ASN's owning organization, its country and the regional registry (RIR) responsible for it, the prefixes it currently announces, and its closest BGP neighbours, a hint at who its upstreams and peers are. If you enter an IP instead of an ASN, the tool first finds which ASN announces that address.
Paste the code into your HTML and the tool shows up on your page, without J-Kit's navigation and ads. It still runs in the browser of whoever visits your site.
<iframe
src="https://jkit.tools/embed/en-US/asn-lookup"
width="100%"
height="600"
style="border:0"
loading="lazy"
title="ASN/BGP Lookup"
></iframe>These references help contextualize formulas, standards, APIs and limitations used on this page. They do not replace professional validation when a result has legal, financial, medical or operational impact.
ASN stands for Autonomous System Number, a number that identifies a network that routes traffic independently on the internet, defining its own routing policy via BGP. Internet service providers, cloud providers, large companies and universities typically have their own.
Look up an ASN directly (AS15169 or 15169) or an IP address, and the tool finds the ASN announcing that address on the internet. Data comes from RIPEstat, RIPE NCC's public routing statistics API, straight from your browser.
The lookup runs directly from your browser against RIPEstat's public API (RIPE NCC), the J-Kit server never intermediates that call. ASN, prefix and BGP adjacency data are public internet routing data, the same information any network announces to its neighbours.