Part 1. Defining performance

The key to improving the performance of your websites is understanding how web pages work. These first two chapters teach the skills that you, the developer, will need to master when improving the performance of your web pages, and the tools you will use to create performance charts.

You’ll begin (chapter 1) by learning about the importance of delivering fast web pages to your users and the impact that slower web pages can have on modern businesses. In chapter 2, you’ll learn about the performance cycle and how to use this technique to take a step-by-step approach to improving web page performance.

Throughout this book there is a strong emphasis on the front end of a website and in these chapters you learn why it is important to start with the front end when aiming to improve performance. The Performance Golden Rule states that developers should “optimize front-end performance first, because that’s where 80% or more of the end-user response time is spent.” This rule is the basis for the majority of this book.