
Description: WebPageTest is an open-source website performance testing tool. It allows users to test website load speeds from different locations around the world and provides performance metrics like First Contentful Paint, Speed Index, and Time to Interactive.
Type: Open Source Test Automation Framework
Founded: 2011
Primary Use: Mobile app testing automation
Supported Platforms: iOS, Android, Windows

Description: YSlow is a Firefox and Chrome browser extension that analyzes web pages and suggests ways to improve their performance based on Yahoo!'s performance best practices. It grades performance and provides tips to optimize page load speed.
Type: Cloud-based Test Automation Platform
Founded: 2015
Primary Use: Web, mobile, and API testing
Supported Platforms: Web, iOS, Android, API