15 Best Free Online ASN Lookup Websites

Here is a list of best free online ASN lookup websites. ASN or Autonomous System Numbers is a set of routable IP prefixes belonging to autonomous networks. Autonomous Networks are assigned to large organizations which can manage, control, and supervise autonomous networks. Autonomous Networks and Systems are a large part of the Internet. When autonomous networks communicate with each other they need unique identifiers like AS Numbers. By looking up a specific AS Number, users can find out the organizations with which it is associated, Company Origin, Company State, CIDR Range, ASN Status, etc. If you also want to look up a specific AS Number, then check out these online ASN lookup websites.

Using these websites, users can look up AS numbers like AS701, AS41354, AS721, and more. Although, most of these websites can only look up one AS number at a time. After performing the lookup operation, these websites show all the necessary AS lookup information on their main interfaces that users can also copy. To help out new users, I have also included the steps to AS lookup in the description of each website.

These websites also offer multiple online tools such as Email Health Reports, SMTP Diagnostics, IP Geolocation API, IP to Company, and more. Go through the list to know more about these websites.

My Favorite Online ASN Lookup Website:

dnschecker.org is my favorite website as it shows all the essential information after looking up a specific AS Number. Plus, it also offers a good set of free online tools.

You can also check out lists of best free Online OUI Lookup, Online MX Lookup, and Online Reverse NSlookup websites.

dnschecker.org

dnschecker.org is a free online ASN lookup website. Using this website, users can perform an ASN Whois lookup operation against a specific AS number to find out which company is using that ASN and its origin country. After performing the operation, it can also show information like AS-Block, Description, Aut-Num, ASN Status, AS Name, Source of ASN Information, and more. Plus, it also answers various queries associated with ASN like what is ASN, how autonomous systems connect, etc. Now, follow the below steps.

How to perform ASN lookup online using dnschecker.org:

Go to this website and open up the ASN WHOIS Lookup tool.
After that, enter the AS Number in the ASN Number field.
Next, click on the Lookup ASN button to initiate the lookup process.
Lastly, view all the obtained information.

Additional Features:

This website also offers additional online tools like DNS Lookup, Reverse IP Lookup, NS Lookup, MX Lookup, and more.

Final Thoughts:

It is one of the best free online ASN Lookup websites that shows all the essential data associated with an AS number.

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mxtoolbox.com

mxtoolbox.com is a free online ASN lookup website. Using this website, users can find out the total amount of IPs for a given ASN number. It also shows the names of services that are utilizing a given ASN range along with the CIDR range. Along with ASN Lookup, users can also use it to perform MS Lookup, DNS Lookup, AAAA Lookup, CERT Lookup, etc., operations. Nom, follow the below steps.

How to perform ASN lookup operation online using mxtoolbox.com:

Visit this website and choose MX Lookup from the Lookup menu.
After that, enter the AS Number in the input field.
Next, click on the ASN Lookup button to view all the AS Numbers, AS Service Names, and CIDR Range values.

Additional Features:

This website also has additional Email Blacklist Check, Email Health Reports, SMTP Diagnostics, etc., features.

Final Thoughts:

It is a good online ASN lookup website that allows users to perform ASN lookup for a specific AS Number.

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hackertarget.com

hackertarget.com is another free online ASN lookup website. This website comes with a simple Autonomous System Lookup tool that can quickly perform ASN lookup operations. After performing the operation, it shows the organization with which it is associated along with AS Name and AS Prefixes. Now, follow the below steps.

How to perform ASN lookup online using hackertarget.com:

Visit this website using the given link.
After that, enter one or more valid AS numbers in separate lines that you want to look up.
Now, click on the Lookup ASN button to view all the essential ASN information.

Additional Features:

This website also offers online Nmap Port Scanner, Schedule Nmap Scanners, SSL Scanner, Domain Profiler, etc., online tools.

Final Thoughts:

It is another good online ASN lookup website that anyone can use to extract essential information associated with one or more ASN numbers.

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iplocation.io

iplocation.io is another free online ASN Whois Lookup website. Through this website, users can quickly perform an ASN lookup for a valid ANS number. After performing the lookup operation, it shows ASNumber range, ASName, ASHandle, RegDate, Organization Name, Organization ID, etc., values. It also lets users copy all the lookup data to their clipboard. Now, follow the below steps.

How to perform ANS lookup online using iplocation.io:

Visit this website and choose the ASN Whois Lookup tool.
After that, enter a valid AS number in the input field.
Now, click on the Find button to start the lookup process.
Finally, view all the obtained data that you can also copy.

Additional Features:

Using this website, users can also perform some additional operations like IPV4 to IPV6 Conversion, DNS Lookup, Subnet Calculation, IPV6 Compression., etc., operations.

Final Thoughts:

It is another capable online ANS lookup website that anyone can use to perform the ANS lookup operation.

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ipinfo.io

ipinfo.io is yet another free online ASN lookup website. This website comes with an IP to ASN API tool that can also be used as an ASN lookup tool. In this tool, users just need to enter a valid AS number to view information associated with it like the Company Name associated with the ASN number, Country, Domain, Registry, and more. Now, follow the below steps.

How to perform ASN lookup online using ipinfo.io:

Visit this website and choose IP to ASN API tool.
After that, enter the AS number in the input field.
Now, view all the details associated with the given AS number.

Additional Features:

This website also offers multiple products like IP Geolocation API, IP to Company, IP to Mobile Carrier, IP Range API, IP Whois API, and more.

Final Thoughts:

It is another good online ASN lookup website that anyone can use to quickly extract important information associated with an AS Number.

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asnlookup.com

asnlookup.com is another free online ASN lookup website. Using this website, users can look up information associated with one ASN number. Some of the information that it extracts are ASN Name, Organization Name, Organization ID, Country Code, IPv4 Prefix range, and more. Now, follow the below steps.

How to perform ASN lookup online using asnlookup.com:

Open the interface of this website and access the lookup tool.
After that, submit one valid AS number in the input field.
Next, click on the Look up! button to view all the information associated with an AS number.

Additional Features:

This website also lets users look up updated information about organizations and registered IP addresses.

Final Thoughts:

It is another capable online ASN lookup website that anyone can use to quickly lookup updated information about an AS number.

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bgpview.io

bgpview.io is another free online ASN lookup website. This website users lets look up ASNs, IPv4 Prefixes, and IPv6 Prefixes and their associated information. To do that, users just need to enter the AS Number without putting AS before the numerical part in the input section. After performing the lookup, it shows ASN Names, Description, RIR, Country of Origin, etc. Now, follow the below steps.

How to perform ASN lookup online using bgpview.io:

Visit this website using the provided link.
After that, enter the AS number in the input field.
Now, start the lookup process to view Organization Name, RIR, ASN Names, etc., information.

Additional Features:

This website can also be used to view the worldwide BGP map highlighting resources allocated to each country.

Final Thoughts:

It is another good online ASN lookup website that anyone can use to perform ASN lookup operations.

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asrank.caida.org

asrank.caida.org is another free online ASN lookup website. This website is mainly used to check the CAIDA’s ranking for autonomous systems. Although, users can also use it to perform the ASN lookup for a specific AS Number. Some of the information that it shows after performing the lookup is AS Name, Organization Name, Country, AS Rank, AS Degree, Tested IP Blocks, and more. Now, follow the below steps.

How to perform ASN lookup online using asrank.caida.org:

Visit this website and enter the AS number in the input section.
After that, click on the Search button to start the lookup process.
Finally, view all the obtained values on its interface.

Final Thoughts:

It is another simple-to-use online ASN lookup website that can quickly look up any valid AS number.

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bigdatacloud.com

bigdatacloud.com is another free online ASN lookup website. This website allows users to lookup for a specific AS number. As the result, it shows the coverage area of the specific network over the world map along with associated details like Organization Name, IPv4 Space Rank, Registration Change, AS Name, and more. Plus, using this app is also quite simple. Now, follow the below steps.

How to perform ASN lookup online using bigdatacloud.com:

Launch this website and access the ASN lookup tool.
After that, enter a valid AS number in the input section.
Now, click on the Lookup button to view the ASN coverage area and other related details.

Additional Features:

API Packages: It offers multiple API packages like IP Geolocation, Reverse Geocoding, Network Engineering, and more.
Tools: It offers online tools like IP Lookup, Network Lookup, Update My Location, etc., tools.
Insights: It offers insights about Tor Exit Nodes, Bogon Routes, IP Geolocation per Country, etc.

Final Thoughts:

It is a feature-rich online ASN lookup website that also shows the coverage area of a specific ASN over a map.

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bgp.he.net

bgp.he.net is another free online ASN lookup website. This website offers multiple internet online services one of which is an ASN lookup service. To use this service, users need to lookup for a valid AS number. In the results, it will give you all the information related to it like Company Website, Country of Origin, IPs Originated, Prefixes Originated, etc. Besides this, it also shows the IPv4 Peers vs IPv6 Peers graph in the context of the submitted AS number. Now, follow the below steps.

How to perform ASN lookup online using bgp.he.net:

Visit this website using the provided link.
After that, enter a valid AS number in the search field.
Next, initiate the search to view all the AS Information.

Additional Features:

This website also offers additional tools that may come in handy like Bogon Routes, DNS Report, Free IPv6 Tunnel, Going Native, Multi Origin Routes, etc.

Final Thoughts:

It is another good online ASN lookup website that allows users to quickly obtain all the necessary information about a specific AS number.

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viewdns.info

viewdns.info is a free online ASN lookup website. This website comes with a dedicated ASN lookup tool that only accepts numerical values of an AS number as input. Within seconds, it can lookup and show you all the information associated with the submitted AS number like AS Name, AS Handle, Organization Name, Organization ID, Origin Country, Registration Date, and more. Now, check out the below steps.

How to perform ASN lookup online using viewdns.info:

Launch this website and access the ASN Lookup tool.
Now, submit one AS number.
Next, click on the Go button to initiate the lookup process.
Lastly, view ASN information on its main interface.

Additional Features:

This website also offers free and paid APIs along with research content related to the Internet, DNS Cache, Domain, etc., topics.

Final Thoughts:

It is another simple-to-use online ASN lookup website through which users can easily obtain information associated with an AS number.

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traceroute-online.com

traceroute-online.com is another free online ASN lookup website. It is another good online ASN lookup website that uses the a valid AS number to fetch its data like IPv4 Count, Name of Company, AS Numbers, and all IP ranges assigned to the block. Now, follow the below steps.

How to perform ASN lookup online using traceroute-online.com:

Visit this website using the provided link.
After that, enter an AS number that you want to lookup.
Now, click on the Lookup! button to view the range of IPs assigned to it along with other associated details.

Additional Features:

This website also comes with additional Check DNS< MTR, and Internet Maps tools.

Final Thoughts:

It is another good online ASN lookup website that anyone can use to quickly lookup a specific AS number.

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cleantalk.org

cleantalk.org is another free online ASN lookup website. This website is mainly used to track the IP addresses in spam messages to help ISP companies detect suspicious activities. Although, it can also be used to look up a specific AS number and information associated with like like Organization Name, AS Name, Registration Date, Postal Code, Country of Origin, and more. It also shows the spam activity log for the past 14 months. Now, follow the below steps.

How to perform ASN lookup online using cleantalk.org:

Visit this website using the given link.
After that, submit one AS Number in the search field.
Next, click on the Find button to initiate the lookup process.
Lastly, view all the ASN lookup data on its interface along with spam statistics and spam activity log.

Additional Features:

This website also offers additional online solutions like Spam Firewall, Malware Web Scanner, Report IP, SSL Certificates, CSR Generator, and more.

Final Thoughts:

It is another capable online ASN lookup website that also shows spam statistics and spam activity logs associated with specific AS Numbers.

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ripe.net

ripe.net is another free online ASN lookup website. This website comes with a simple site search feature that can look at an AS number. Although, it doesn’t show too much information related to an ASN compared to other similar websites. Some of the information that it shows are AS Block Range, Description, Creation Date, Last Modified Date, and Source. Now, follow the below steps.

How to perform ASN lookup online using ripe.net:

Go to this website and access the Site Search feature.
After that, enter the AS number and hit the Seach button.
Next, view the obtained ASN lookup information that it extracts.

Additional Features:

This website also shows IPs and ASNs tools like Request IPv6, Request an AS Number, Inter-RIR Transfers, and more.

Final Thoughts:

It is another good online ASN lookup website that anyone can use to lookup basic AS number details.

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devina.io

devina.io is a free online ASN lookup website. This website comes with multiple network tools one of which is an ASN Lookup tool. Using this tool, users can look up information associated with one AS Number at a time. After the lookup, it shows information like AS Number Range, AS Name, AS Handle, Registration Date, Organization Name, Address, and more. Now, follow the below steps.

How to perform ASN lookup online using devina.io:

Visit this website and go to the ASN Lookup tool.
After that, enter one AS Number in the input field and click on the Lookup button.
Next, view and copy ASN lookup data from its interface.