Whether you’re doing research on any given topic, or just want to discover new websites which are similar to your favorite one – here are 5 free and useful ways to find and discover related websites.

1. How to find websites which Google thinks are alike

If you add “related:” to your search term, Google will return sites which are related to your query.  For example, “related:friedbeef.com” would return sites which are similiar to friedbeef.com.  Note there can be no space between the "related:" and the web page url.

2. How to find related sites based on what other people visit

Alexa, the service which provides free website information works through a toolbar which tracks all your browser traffic. 

By tracking users across websites, Alexa is able to come up with a list of related sites fairly accurately, as they can deduce relationships between Web sites based on visit patterns.  All you need to do is search for any website and click on the ‘related links’ tab.

3. How to find related sites based on community votes

Siteslike is a service which provides you related sites, and also allows you to vote and determine how similar those sites really are, so you can help others in the future. 

4. How to use Google trends to determine related sites

Just like Alexa, Google Trends for websites also tracks web browsing patterns and can determine what sites are related based on what people have visited.  The advantage here is that you can also filter results by country and get a more granulated result.

5. The most convenient way to find related websites

Among all the items described in this post, Similar Site Search provided the best and most relevant results during testing. 

Not only does it give the most accurate results, it also gives each site a score citing how relevant it is.  For convenience it also comes with a firefox extension and a bookmarklet as well, so all similar site searches can be done on the fly.  Highly recommended.

Do you search for related websites?  Tell us about it in the comments :)