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IP to ASN mapping and ASN lookup are possible with IPinfo’s ASN API, giving our customers access to a database that includes ASN details for every IP address and every ASN’s related domains, allocation date, registry name, total number of IP addresses, and assigned prefixes.

  • asn:"AS13335",
  • name:"Cloudflare, Inc.",
  • domain:"cloudflare.com",
  • route:"",
  • type:"business",

Advanced usage enabled

Group up to a thousand
lookups in one API request

ASN API can be used with our /batch endpoint. It allows you to group up to 1000 API requests into a single request. This can really speed up processing of bulk IP lookups, and it can also be useful if you want to lookup information across our different APIs.

Andrew Morris

We needed to further contextualize Internet scanners, crawlers, and bots. Origin networks, data centers, ASNs, and countries are a huge component of that. We were looking for a faster, more developer-friendly alternative to existing geo-IP providers. A close friend of mine hit the IPinfo API with cURL, and I saw all the information we needed.

Andrew Morris Founder / CEO, GreyNoise

Billion API requests last month

Reliable & updated ASN data

IPinfo offers the most reliable IP to ASN lookup service on the web. Our proprietary network data sets are updated every day so that our ASN database is as accurate and complete as it gets.

  • Country
  • Number of IPs
  • Allocation date
  • Hosting
  • Registry
  • Hosting service

A few ways to use our ASN API

  • IPinfo's ASN API can provide information on whether an IP address belongs to a consumer, business, or hosting provider. You can utilize IP type data to better understand what type of experience to deliver to your users. You will be able to easily differentiate between IPs based on their intended use and assignment.
  • Resolving the IP address to ASN for users that visit your website will provide your business with insight on which ISPs are common among your IP traffic. This data can help you make inferences about users’ internet connection speeds, data limitations, and so forth.
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Our database downloads contain the same accurate IP address information available with our APIs. These downloads are available in any format (eg. CSV, JSON, MMBD) with additional options to customize the fields.

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Made for developers
Trusted by enterprises

Our database is built, maintained, and supported by our in-house team of developers and engineers. These data experts are ready to troubleshoot problems, build unique use cases, and create additional enterprise solutions.

  • Zapier
  • Snowflake
  • Wordpress
  • Maltego
  • Splunk
  • Palo Alto Networks
  • Heroku
  • Polarity

Supports integrations

Our API integrations merge the power of IPinfo’s proprietary IP address database with other industry-leading platforms. Use your IP WHOIS data at scale with our supported integrations, such as Snowflake, Splunk, Maltego, and beyond.

  • PHP
  • Python
  • Ruby
  • Java
  • Spring
  • Node.js
  • C#
  • Rust

Official libraries

We offer libraries for the most commonly used programming languages and frameworks. Check out our documentation to facilitate easier setup.

Frequently Asked Questions

What is ASN?

ASN stands for Autonomous System Number. These numbers identify autonomous systems (AS) that represent a collection of Internet Protocol prefixes. Universities, governments, large organizations, Internet Service Providers (ISP), and others often operate their own IP network which is identified by an ASN.

What information can be gathered from ASN?

ASN data reveals related domains, allocation dates, the total number of IPs, the RIR (regional internet registries) name, and assigned prefixes.

How is ASN data used?

IPinfo users need ASN data to learn more context about their website visitors, user logins, app users, and more. It can also be used to infer internet connection speed and the type of user behind the ASN.

Why do some IP addresses not have ASN data?

Not all IPs are routable on the internet, but only those for which some AS announced a prefix over BGP, containing that IP address. You can double-check if an IP address is routable here.

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