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ASN WHOIS Lookup

Look up an autonomous system number (ASN) to see who owns it and its registration details.

Enter an autonomous system number with or without the AS prefix, such as AS13335 (Cloudflare) or 32934 (Meta).

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Clear instructions

Find steps, examples and limitations below.

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How to use the ASN WHOIS Lookup

Look up an autonomous system number (ASN) to see who owns it and its registration details.

  1. 1 Enter an AS number with or without the AS prefix, such as AS13335.
  2. 2 Click Look up ASN.
  3. 3 Review the organization and contacts in the registry record.

Example and practical tips

AS15169 returns GOOGLE, registered to Google LLC with ARIN. You will often find ASNs in IP location results, BGP tools and firewall logs.

Frequently asked questions

What is an ASN?

An autonomous system number identifies a network that controls its own routing on the internet, such as an ISP, cloud provider or large company.

Where do I find an IP address’s ASN?

The IP location lookup shows the ASN of any IP address, which you can then look up here.

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