Search any Autonomous System by number or name. Browse the global ASN database — filter by country, type, or size.
Enter an ASN number (e.g. AS15169 or 15169) to jump to its detail page, or a name like Google to search.
100K+
ASNs indexed
240+
Countries covered
4.2B
IPs mapped
BGP
Real routing data
Explore
Explore all registered Autonomous Systems for any country in the world.
United States
2,847 ASNs
Browse →Germany
1,203 ASNs
Browse →France
891 ASNs
Browse →United Kingdom
1,456 ASNs
Browse →Japan
634 ASNs
Browse →China
892 ASNs
Browse →Brazil
541 ASNs
Browse →Australia
423 ASNs
Browse →Netherlands
674 ASNs
Browse →Russia
789 ASNs
Browse →Canada
578 ASNs
Browse →India
445 ASNs
Browse →Rankings
The ten Autonomous Systems with the most announced BGP prefixes globally.
| Rank | ASN | Organization | Country | Prefixes | IPv4 Addresses |
|---|---|---|---|---|---|
| #1 | AS7018 | AT&T Services, Inc. | 🇺🇸 US | 7,220 | 149,004,288 |
| #2 | AS4134 | China Telecom Backbone | 🇨🇳 CN | 6,891 | 115,343,616 |
| #3 | AS7922 | Comcast Cable Communications | 🇺🇸 US | 5,103 | 68,157,440 |
| #4 | AS3356 | Lumen Technologies (Level 3) | 🇺🇸 US | 4,982 | 31,457,280 |
| #5 | AS6389 | BellSouth Telecommunications | 🇺🇸 US | 4,401 | 83,886,080 |
| #6 | AS1221 | Telstra Corporation Limited | 🇦🇺 AU | 4,287 | 55,050,240 |
| #7 | AS6327 | Shaw Communications Inc. | 🇨🇦 CA | 3,941 | 18,874,368 |
| #8 | AS16509 | Amazon Web Services | 🇺🇸 US | 3,802 | 130,023,424 |
| #9 | AS701 | Verizon Business | 🇺🇸 US | 3,654 | 50,331,648 |
| #10 | AS3320 | Deutsche Telekom AG | 🇩🇪 DE | 3,581 | 94,371,840 |
Data sourced from BGP route collectors. Updated every hour.
Breakdown
Every ASN in our database is classified into one of four operational categories.
45,200
Internet Service Providers and carrier networks providing last-mile and transit connectivity to end users.
45% of all ASNs
31,400
Corporate networks and large organisations operating their own IP infrastructure for internal routing.
31% of all ASNs
18,900
Cloud providers, datacentre operators, CDNs, and managed hosting platforms serving third-party workloads.
19% of all ASNs
4,500
National and regional government networks, defence agencies, public-sector institutions, and education networks.
5% of all ASNs
Reference
An Autonomous System Number (ASN) is a globally unique 32-bit integer assigned by a Regional Internet Registry (RIR) to a network — or group of IP prefixes — operated by a single entity under a unified routing policy.
ASNs are the building blocks of the global internet. They are how BGP (Border Gateway Protocol) routers identify and exchange routing information between independent networks: your home ISP, Google's cloud, a university research network — each has its own ASN.
The HostInfo ASN Browser lets you explore the full global ASN registry — search by number, name, or country; inspect prefix announcements; trace peer relationships; and classify networks by operational type.
2-byte ASNs
1 – 65535
Legacy 16-bit range
4-byte ASNs
up to 4B
Modern 32-bit range
{ "asn": "AS15169", "asn_name": "GOOGLE", "asn_type": "hosting", "country": "US", "country_name": "United States", "domain": "google.com", "rir": "ARIN", "num_ips": 4718592, "num_prefixes_v4": 621, "num_prefixes_v6": 84, "peers": [ "AS1299", "AS174", "AS6461" ], "announced_prefixes": [ "8.8.8.0/24", "8.8.4.0/24" ] }
Access the full ASN database programmatically. Lookup by IP or ASN number, get prefix lists, peer data, and organisation details — all in one call.