SEMrush – Any Website. SEMrush is also known for its exceptional accuracy and it’s a reliable tool to check the traffic of a website.SimilarWeb – Any Website. Go to SimilarWeb website, enter any site URL in the search box and hit enter. You will see detailed traffic analysis for the previous month.Alexa – Any Website. The free Alexa tool does not show the estimated number of visitors. Google Analytics [For Site Owners] Google Analytics is the most popular website analysis tool on the planet. Almost every site uses Analytics tag to track traffic and other data.Quantcast [For Site Owners] When you use Quantcast, information is displayed nicely and easy to follow.