ASN Lookup API - Free Autonomous System Number Lookup

IPBot returns network identity under network, including the originating ASN and organization. Use ASN information for routing controls, allow/deny lists, and security analytics.

Network Classification

Identify ISP, hosting, business, or mobile networks automatically.

Organization Info

Get the company name behind any IP for allow/deny list management.

Example

curl -s https://api.ipbot.com/1.1.1.1 | jq ‘.network’

Learn more in the API Reference.

What is an ASN?

An Autonomous System Number (ASN) is a unique identifier assigned to a collection of IP networks that operate under a single administrative domain. Every organization that needs to route traffic on the internet - ISPs, cloud providers, enterprises, universities - must have an ASN.

Think of an ASN as a company ID for the internet. When you see AS15169, that’s Google. AS13335 is Cloudflare. AS7922 is Comcast. The ASN tells you who operates the network, which is valuable for security, analytics, and access control.

ASN Allocation

ASNs are assigned by Regional Internet Registries (RIRs):

Registry	Region	Example Range
ARIN	North America	AS1 - AS65535
RIPE NCC	Europe, Middle East	AS200000+
APNIC	Asia-Pacific	Various
LACNIC	Latin America	Various
AFRINIC	Africa	Various

There are over 100,000 assigned ASNs globally, with thousands of new assignments each year as more organizations connect to the internet.

Network Response Fields

The IPBot API returns comprehensive network data:

{
  "network": {
    "asn": "AS13335",
    "org": "Cloudflare, Inc.",
    "radar": "hosting"
  }
}

Field	Description	Type	Example
asn	Autonomous System Number	string	”AS13335”
org	Organization name	string	”Cloudflare, Inc.”
radar	Network classification	string	”hosting”

Network Classification (Radar)

The radar field classifies the type of network:

Value	Description	Examples
isp	Residential Internet Service Provider	Comcast, AT&T, BT
hosting	Cloud/datacenter/hosting provider	AWS, Google Cloud, DigitalOcean
business	Enterprise/corporate networks	Fortune 500 companies
mobile	Mobile carrier networks	Verizon Wireless, T-Mobile

This classification is critical for fraud detection - transactions from hosting IPs are often more suspicious than isp IPs.

Why ASN Lookup Matters

Security and Fraud Detection

75% of ecommerce businesses are increasing fraud prevention budgets in 2025. ASN lookup is a core component of fraud detection because it reveals the true nature of a connection:

const data = await fetch("https://api.ipbot.com/").then((r) => r.json());

// Flag datacenter connections for additional review
if (data.network.radar === "hosting") {
  addFraudFlag("datacenter_ip", {
    asn: data.network.asn,
    org: data.network.org,
  });
}

// Known VPN providers
const vpnAsns = ["AS9009", "AS212238", "AS62041"]; // Examples
if (vpnAsns.includes(data.network.asn)) {
  addFraudFlag("known_vpn_provider");
}

Traffic Analysis

Understanding your traffic sources helps optimize infrastructure and marketing:

async function analyzeTrafficSources() {
  const visitors = await getRecentVisitors();
  const asnStats = {};

  for (const ip of visitors) {
    const data = await fetch(`https://api.ipbot.com/${ip}`).then((r) =>
      r.json(),
    );
    const asn = data.network.asn;

    asnStats[asn] = asnStats[asn] || {
      org: data.network.org,
      type: data.network.radar,
      count: 0,
    };
    asnStats[asn].count++;
  }

  // Find top ISPs serving your users
  return Object.entries(asnStats)
    .sort((a, b) => b[1].count - a[1].count)
    .slice(0, 10);
}

Access Control

Implement network-based access policies:

import requests

def check_access(client_ip: str) -> bool:
    data = requests.get(f"https://api.ipbot.com/{client_ip}").json()

    # Block hosting/datacenter IPs from signup
    if data["network"]["radar"] == "hosting":
        return False, "Datacenter IPs not allowed for registration"

    # Whitelist specific corporate networks
    allowed_asns = ["AS12345", "AS67890"]  # Your corporate ASNs
    if data["network"]["asn"] in allowed_asns:
        return True, "Corporate network approved"

    return True, "Access granted"

Network Operations

ASN data helps with:

• Peering decisions: Identify who sends you traffic
• CDN placement: Understand geographic distribution
• Troubleshooting: Identify problematic networks
• Capacity planning: Plan for growth from specific ISPs

Notable ASNs

Here are some commonly encountered ASNs:

Cloud Providers

ASN	Organization	Notes
AS16509	Amazon Web Services	Largest cloud provider
AS15169	Google Cloud/Google	Also includes search infrastructure
AS8075	Microsoft Azure	Major cloud platform
AS13335	Cloudflare	CDN and security
AS14061	DigitalOcean	Developer-focused hosting
AS14618	Amazon AWS (alternate)	EC2 services

Major ISPs

ASN	Organization	Region
AS7922	Comcast	US
AS7018	AT&T	US
AS5089	Virgin Media	UK
AS3320	Deutsche Telekom	Germany
AS4134	China Telecom	China
AS4837	China Unicom	China

VPN/Privacy Providers

ASN	Organization	Notes
AS9009	M247	Popular VPN hosting
AS62041	Datacamp	VPN infrastructure
AS212238	Datacamp Limited	VPN services

Integration Examples

JavaScript

async function getNetworkInfo(ip) {
  const response = await fetch(`https://api.ipbot.com/${ip}`);
  const data = await response.json();

  return {
    asn: data.network.asn,
    organization: data.network.org,
    type: data.network.radar,
    isDatacenter: data.network.radar === "hosting",
    isResidential: data.network.radar === "isp",
  };
}

// Usage
const network = await getNetworkInfo("8.8.8.8");
console.log(`${network.organization} (${network.asn}) - ${network.type}`);
// Output: "Google LLC (AS15169) - hosting"

Python

import requests
from dataclasses import dataclass
from typing import Literal

@dataclass
class NetworkInfo:
    asn: str
    org: str
    radar: Literal["isp", "hosting", "business", "mobile"]

    @property
    def is_datacenter(self) -> bool:
        return self.radar == "hosting"

    @property
    def is_residential(self) -> bool:
        return self.radar == "isp"

def get_network_info(ip: str) -> NetworkInfo:
    response = requests.get(f"https://api.ipbot.com/{ip}")
    data = response.json()

    return NetworkInfo(
        asn=data["network"]["asn"],
        org=data["network"]["org"],
        radar=data["network"]["radar"]
    )

# Usage
network = get_network_info("8.8.8.8")
print(f"{network.org} ({network.asn}) - datacenter: {network.is_datacenter}")

cURL Examples

# Get network info for any IP
curl -s https://api.ipbot.com/8.8.8.8 | jq '.network'

# Get just the ASN
curl -s https://api.ipbot.com/1.1.1.1 | jq -r '.network.asn'
# Output: AS13335

# Get organization name
curl -s https://api.ipbot.com/1.1.1.1 | jq -r '.network.org'
# Output: Cloudflare, Inc.

# Check if datacenter
curl -s https://api.ipbot.com/8.8.8.8 | jq -r '.network.radar'
# Output: hosting

# Get both location and network for context
curl -s https://api.ipbot.com/8.8.8.8 | jq '{location: .location.country, network: .network}'

Use Cases

Bot Detection

Datacenter IPs are often used by bots and scrapers:

async function assessBotRisk(clientIp, userAgent) {
  const data = await fetch(`https://api.ipbot.com/${clientIp}`).then((r) =>
    r.json(),
  );

  let botScore = 0;

  // Datacenter IP
  if (data.network.radar === "hosting") {
    botScore += 40;
  }

  // Known bot hosting ASNs
  const botHostingAsns = ["AS62567", "AS9009"];
  if (botHostingAsns.includes(data.network.asn)) {
    botScore += 30;
  }

  // Combine with user agent analysis
  if (
    !userAgent ||
    userAgent.includes("bot") ||
    userAgent.includes("crawler")
  ) {
    botScore += 30;
  }

  return { score: botScore, isLikelyBot: botScore >= 50 };
}

Competitive Intelligence

Understand who is accessing your site:

// Track visits from competitor networks
const competitorAsns = {
  AS15169: "Google",
  AS14618: "Amazon",
  AS8075: "Microsoft",
};

async function trackCompetitorVisit(ip, page) {
  const data = await fetch(`https://api.ipbot.com/${ip}`).then((r) => r.json());

  if (competitorAsns[data.network.asn]) {
    analytics.track("competitor_visit", {
      company: competitorAsns[data.network.asn],
      page: page,
      asn: data.network.asn,
    });
  }
}

Rate Limiting by Network Type

Apply different rate limits based on network classification:

def get_rate_limit(client_ip: str) -> int:
    data = requests.get(f"https://api.ipbot.com/{client_ip}").json()

    if data["network"]["radar"] == "hosting":
        return 10  # Strict limit for datacenters
    elif data["network"]["radar"] == "mobile":
        return 100  # More lenient for mobile
    else:
        return 60  # Default for residential

Related Documentation

• API Reference - Full endpoint documentation
• Response Schema - Complete field reference
• IP Geolocation - Location data
• Proxy Detection - VPN and proxy detection
• IP Reputation - Risk scoring and threat data