Similar Websites API

The Similar Websites API returns 40 similar websites and their similarity score for a given domain in either XML or JSON.


Returns 40 Similar Websites and their similarity score for a given domain

What is the similarity score?

The ability to return a list of related websites according to a specific website or topic was SimilarWeb’s first breakthrough. Search engines will return websites based on a specific query, but will not recognize that users who visit would also find relevant content on ESPN’s website. The similarity system is based on a number of inputs including website structure, link analysis, user surfing behavior and a large community of user rankings. Under the hood, a supervised learning algorithm generates accurate results which are then cross validated and tested in-house by our data quality team


Params Description
Domain Enter your target domain including only the top-level and second-level names, ie: ""
UserKey (api_key) Enter the user key sent to you by email. You can also find your user key in the API dashboard.
Start Month (start_date) Start Month (YYYY-MM)
End Month (end_date) End Month (YYYY-MM)

One request to this API is worth 3 hits

Please note that sending one request to the SimilarSites API results in 3 hits being counted against your total number of monthly hits.

Example: Similar Websites API input for ""


Example: Similar Websites API output in json for ""



  1. How do you decide which websites are similar?

    Our Similarty results are based on our proprietary, advanced technology including:
    -Automatic Tagging Systems
    -Website Hyperlink Structures
    -Complex Website Categorization
    -Global Internet users Traffic Patterns and Statistics
    -User ratings
    For a more detailed information on our technology and how it can be used in different ways, please visit our technology section in SimilarGroup website.

  2. What does the similarity score mean and how can I read it?

    Every result is scored between 0 and 1.0 .
    The closer the score is to 1.0, the more similar a website is.

  3. Can I get more than 40 Similar Websites results?

    At this point our API only provides up to 40 results per query.