https://www.cnbc.com/2018/08/08/youtube-is-about-to-pass-facebook-as-the-second-biggest-website-accor.html

In the competition to be top website, Facebook may soon cede its runner-up position to YouTube, according to a new study shared with CNBC by market research firm SimilarWeb.

The five websites receiving the most traffic in the U.S. in the last several years have been Google, Facebook, YouTube, Yahoo and Amazon, in that order. However, Facebook has seen a severe decline in page visits, from 8.5 billion in August 2016 to 4.7 billion in the last two years, according to the study. Although Facebook's app traffic has grown, it is not enough to makeup for that loss, the study said.