How does Similarweb categorize domains?

Each website in Similarweb is categorized based on the Similarweb categorization engine. Our code assigns a category for any website using content tags, similarity results, and a learning set of millions of websites that have verified category assignments. Our engine can accurately classify an unknown website into one of 25 main categories and 219 sub-categories. You can see the full list here.

How does Similarweb measure the accuracy of categories?

Similarweb has a categorization engine that is based on a proprietary algorithm that both categorizes new sites and reviews sites that already have a category. The engine refreshes each month (alongside the monthly snapshot release). We have a dedicated team of data scientists who are constantly working to strengthen the accuracy of our categorization engine.

The algorithm is based on many inputs, such as: 

  • content on the website itself,

  • search keywords that drive traffic to the website,

  • incoming and outgoing link relationships between websites,

  • many more data points.

We can also re-categorize some sites manually (for example, if a request comes through to Support).

My site is not listed in the correct industry; how can I change it?

Please reach out to your account manager, or to our Support team.

Do we categorize subdomains?

Most subdomains are not categorized.

However, we do make some exceptions, determined by an algorithm that identifies a set list of subdomains to categorize. The algorithm detects subdomains that are significant and unique in relation to the main domain, so that the subdomain could be considered a separate website that requires different categorization.

For example, is a significant and unique subdomain that warrants a different categorization than

Can you change the category and/or the functionality of a subdomain?

Unfortunately, it's not possible to change the category and/or the functionality of a subdomain.

Was this article helpful?
16 out of 27 found this helpful