Fiddler is a program that enables users to perform HTTP debugging on proxy servers. This program was developed by Eric Lawrence and was first released in October 2009. The program got its name by its feature that allows users to “fiddle” with HTTP traffic as it is being sent. HTTP or Hypertext Transfer Protocol is a type of an application protocol for distributed collaborative, and hypermedia information systems. HTTP is the main form of data communication used by the World Wide Web. Fiddler provides users with tools that capture HTTP traffic and logs it for the user to review , support for interception and tampering with HTTPS traffic as well as working with instant messaging programs.
Fiddler has the capability to debug web proxy servers that run on different Internet browsers such as Internet Explorer, Mozilla Firefox, Google Chrome, Opera, and many more. This program is designed to be used by network administrators who need to monitor Web traffic by user sessions either locally or remotely. The program collects Web and usage statistics, identifies various errors, and provides different analysis tools that will send a detailed report of Web traffic to users. Fiddler features a user interface that is divided into two parts. The left panel shows the number of active HTTP sessions that also display information such as the session number, result, host, and the URL. The right panel contains three tabs that analyze and log HTTP traffic. This section contains three tabs: Performance Statistics, Session Inspector, and Request Builder.