ASN Lookup
Enter any public IP address to find its ASN — the autonomous system number identifying the network that announces it — plus the organization, ISP, and country behind it.
What is an ASN?
The internet is a network of roughly 100,000 independently operated networks called
autonomous systems — ISPs, cloud providers, universities, large companies.
Each one is identified by an autonomous system number (ASN), such as
AS15169 for Google. Routers use ASNs with the BGP protocol to decide how traffic
travels between networks, and every public IP address is announced by exactly one AS at a
time.
What an ASN lookup tells you
- Who really operates an IP: the ASN owner is the network operator, even when the geolocation looks odd.
- Hosting vs residential: an IP announced by a cloud ASN (AWS, OVH, Hetzner…) is a server, not a home user — useful for spotting bots and VPN exits.
- Abuse reporting: the AS operator is the right contact for reporting attacks or spam from an address.
Related tools
Run a full IP lookup for location and timezone, check the reverse DNS (PTR) record of the same address, or find your own IP to look up first.