Fiddler

Fiddler is a proxy that aims to debug any problems related to the HTTP traffic between your computer and the Internet.

The interface is divided into different tabs where you can access statistics for each website you visit. It also has an 'inspector' for viewing the content of each request and corresponding response in different formats.

You can also set filters for unwanted traffic to save time, or take advantage of the time bar, which shows you the transfer for a specific HTTP session.

Fiddler is a comprehensive tool that, despite its small size, includes a number of useful features for anyone who has medium to advanced knowledge on the subject.