Using WebPageTest

Preface

WebPageTest is a synthetic performance testing tool for websites that has evolved since its original public release in 2008. I originally developed it at AOL as a tool to provide developers information on the page load experience for end users (with realistic connectivity and in browsers that were used to visit sites). At the time, most developers used Firefox because the developer tools were much better than what were available in any other browser, and the data center that served the pages was right across the street, connected by fast ethernet to the office. In that environment, all pages loaded unrealistically fast and we needed a way to analyze and share the performance that users experienced in Internet Explorer, on Windows, and in the slow connectivity environments that existed at the time (dialup and slow DSL primarily).

The features, supported browsers, and platforms have evolved over time, but the core mission has been very consistent: to provide detailed information to developers about the loading performance of their pages in a realistic end user environment.

WebPageTest is an open source project on GitHub, available for people to install and use in whatever environment they would like, with a very liberal BSD license. There are several commercial testing platforms that use all or some of the WebPageTest code and it also powers the HTTP Archive (httparchive.org). The most visible instance of WebPageTest is the free, public one at webpagetest.org, which is a ...