ASN Lookup

The internet is made of tens of thousands of networks, each identified by an autonomous system number (ASN), such as AS13335 for Cloudflare or AS15169 for Google. Enter an ASN, an IP address or a domain to see who operates the network, its country, the IP ranges it announces, how many IPv4 addresses that covers, and which networks it connects to. Data comes from RIPEstat's public BGP data, which covers every region.

How to use ASN Lookup

1. Enter an AS number (AS13335 or 13335), an IP address or a domain name.
2. Click Look up.
3. Read the owner and summary, then browse the announced prefixes and neighbouring networks.

When it comes in handy

• Finding who owns an IP address that appears in your logs.
• Building firewall allow or block lists for a whole network.
• Researching hosting providers and ISPs.

Frequently asked questions

What are upstreams?

Networks that provide transit to this one, as seen in public BGP data. The list is inferred from routes, so it is a good guide rather than a contract list.

Why does an IP show a different company from the website owner?

The ASN belongs to the network that hosts the IP, such as a cloud provider or CDN, not to the website using it.