This is a list of the most popular websites worldwide according to the top 100 lists published by Alexa Internet, as of December 28, 2016, and SimilarWeb, as of November 2016.
List of most popular websites Wikipedia
Alexa ranks websites based on a combined measure of page views and unique site users, and creates a list of most popular websites based on this ranking time-averaged over three-month periods. Only the site's highest-level domain is recorded, aggregating any subdomains.
SimilarWeb ranks websites based on a panel of millions of Internet users, International/U.S. internet service providers, direct measurement of web traffic from data from thousands of websites and web crawlers scanning public websites.