If you are doing competitive analysis, nothing beats the accuracy and depth of data provided by the SEMRush traffic Analytics tool.
SEMRush is the pioneer in competitive analysis and using their traffic analytics toolkit; you could quickly find the following data: total number of visits to a website in a month, bounce rate, pages/visit and much more, traffic sources (Find out from which location a website is getting traffic from), find which social media platform is sending traffic, find Paid ads traffic and sub-domains along with traffic estimation
SimilarWeb is another popular traffic estimation tool to get traffic overview of a website. In my testing, the website offers one of the most comprehensive data about website traffic and other important matrices.
Using the SimilarWeb tool, you can find the following data about any website: traffic overview, total visits, avg. visit duration, bounce rate, traffic by countries, search traffic, social traffic, audience interest, and competitors & similar sites.
The traffic source let you find out which all are the top traffic source for a website. An advertiser can quickly discover websites that are using low-quality tricks to inflate their traffic. At the same time, marketers and bloggers can find new untapped traffic source.
SimilarWeb offers free and a Pro plan. The free plan is decent enough to give you a traffic estimate about a website. However, for more detailed data, you need SimilarWeb Pro, which offers an Enterprise plan.
On the fun side, If you are a website owner, you will also find the website Global, Country and category rank useful.
There are more website traffic report tools available in the market. However, these two helps you quickly find the details you are looking for.
Similarweb being a free tool is idle for most of the advertisers and marketers who are looking to get quick traffic estimation of a website. For others who are into competitive analysis, SEMRush traffic analytics provide the in-depth website traffic report and ranking.
Depending upon your requirements, you could pick either of them.