
Description: Fiddler is a free web debugging proxy which logs all HTTP(S) traffic between your computer and the Internet. It allows developers to inspect traffic, set breakpoints, and fiddle with incoming or outgoing data. Fiddler can be used to debug traffic from virtually any application that supports a proxy like web browsers, mobile apps, IoT devices, and more.
Type: Open Source Test Automation Framework
Founded: 2011
Primary Use: Mobile app testing automation
Supported Platforms: iOS, Android, Windows

Description: HTTP Toolkit is an open-source web debugging proxy and HTTP inspection tool. It allows developers to intercept, inspect, and modify HTTP requests and responses as they pass between a browser or application and the server.
Type: Cloud-based Test Automation Platform
Founded: 2015
Primary Use: Web, mobile, and API testing
Supported Platforms: Web, iOS, Android, API