ISC Domain Survey


What is the ISC Domain Survey?

Internet Systems Consortium’s Internet Domain Survey, which was started by Network Wizards, is the longest-running survey of the number of computers connected to the Internet. This data provides an in-depth look at the active domains on the Internet. Despite its name, the ISC Domain Survey is not a survey of domains. It is a survey of IPv4 addresses that have a domain name attached to them.

How many people use the Internet?

There is no way to determine how many users are on the net, besides making guesses and estimates. Our references tab includes pointers to other companies that do surveys to estimate the number of users on the Internet.

How big is the Internet?

We consider the numbers presented in the domain survey to be fairly good estimates of the minimum size of the Internet. We cannot tell if there are hosts or domains we could not locate.

In summary, it is not possible to determine the exact size of the Internet, where hosts are located, or how many users there are.

How do I figure out the breakdown of hosts per country from your data?

You can’t. There is not necessarily any correlation between a host’s domain name and where it is actually located. A host with a .NL domain name could easily be located in the U.S. or any other country. In addition, hosts under domains EDU/ORG/NET/COM/INT could be located anywhere. There is no way to determine where a host is without asking its administrator.

How did you compute the adjusted host count figures?

We start with the figure we published for each old domain survey (on the distribution by domain name charts), in the column named “Percent Domains Missed”. If for example it says “20%” domains missed, this means we got 80% of the domains, or 0.80. We then take the total host count and divide it by this number. For example if the hostcount was 800 and we missed 20% of the domains, we would divide 800 by 0.80 to arrive at an adjusted host count of 1000.

What is a host?

A host used to be a single machine on the net. However, the definitions of a host has changed in recent years due to virtual hosting, where a single machine acts like multiple systems (and has multiple domain names and IP addresses). Ideally, a virtual host will act and look exactly like a regular host, so we count them equally.

What is the relation between a host and a network number?

There is not necessarily any correlation between a network number and a domain name. A single network number could span many countries, and a single domain may have hosts on multiple network numbers.

Can I have permission to reproduce your data or charts?

You have permission to reproduce our data provided that you mention the source as “Source: Internet Systems Consortium, Inc. (”. However you must ask our permission to publish derivative works based on our data. In those cases you must say your data or charts are “Based on data from Internet Systems Consortium, Inc. (”

Is the raw data available?

The raw data from the surveys can be purchased from ISC. The datasets are on DVD or can be delivered online. The raw data is IP address and corresponding hostname, i.e:

In a recent survey, we found more than 1 billion hosts. Therefore, the corresponding datasets, especially for the .com, .net, .edu, and .org TLDs, are quite large. For example, the .com file is more than 170MB zipped. Please assure you have the appropriate tools for managing large files.

All data is provided on DVD or online in a format that can easily be imported into most popular databases. If you would like to purchase a copy, please go to our order form. We can provide you with sample data, but its format and structure will be identical to the dozen lines above. If you are asking for a sample so that you can learn the structure of the data, just look at those lines. If you have some other reason for needing a sample, please contact us.

What if I order the raw data, and it isn’t the information I need?

Please read the License Terms carefully before ordering the data, as we can not offer refunds.

Do you have a mailing list for survey announcements?

The survey is currently done in late January and July and usually published the first week of the following month. If you would like to be notified when the latest survey is published, please click here for our mailing list manager.

Last modified: August 18, 2017 at 12:53 pm