
Description: Requestly is a browser extension and web debugging proxy that allows you to modify network requests and responses. It can be used for testing, debugging, automation, mock REST APIs, and modifying requests and responses on the fly.
Type: Open Source Test Automation Framework
Founded: 2011
Primary Use: Mobile app testing automation
Supported Platforms: iOS, Android, Windows

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: Cloud-based Test Automation Platform
Founded: 2015
Primary Use: Web, mobile, and API testing
Supported Platforms: Web, iOS, Android, API