Issue link: https://read.uberflip.com/i/1146286
xiv | Preface Chapter 1, Rule 1: Make Fewer HTTP Requests describes why extra HTTP requests have the biggest impact on performance, and discusses ways to reduce these HTTP requests including image maps, CSS sprites, inline images using data: URLs, and combining scripts and stylesheets. Chapter 2, Rule 2: Use a Content Delivery Network highlights the advantages of using a content delivery network. Chapter 3, Rule 3: Add an Expires Header digs into how a simple HTTP header dra- matically improves your web pages by using the browser's cache. Chapter 4, Rule 4: Gzip Components explains how compression works and how to enable it for your web servers, and discusses some of the compatibility issues that exist today. Chapter 5, Rule 5: Put Stylesheets at the Top reveals how stylesheets affect the render- ing of your page. Chapter 6, Rule 6: Put Scripts at the Bottom shows how scripts affect rendering and downloading in the browser. Chapter 7, Rule 7: Avoid CSS Expressions discusses the use of CSS expressions and the importance of quantifying their impact. Chapter 8, Rule 8: Make JavaScript and CSS External talks about the tradeoffs of inlining your JavaScript and CSS versus putting them in external files. Chapter 9, Rule 9: Reduce DNS Lookups highlights the often-overlooked impact of resolving domain names. Chapter 10, Rule 10: Minify JavaScript quantifies the benefits of removing whitespace from your JavaScript. Chapter 11, Rule 11: Avoid Redirects warns against using redirects, and provides alternatives that you can use instead. Chapter 12, Rule 12: Remove Duplicate Scripts reveals what happens if a script is included twice in a page. Chapter 13, Rule 13: Configure ETags describes how ETags work and why the default implementation is bad for anyone with more than one web server. Chapter 14, Rule 14: Make Ajax Cacheable emphasizes the importance of keeping these performance rules in mind when using Ajax. Chapter 15, Deconstructing 10 Top Sites gives examples of how to identify perfor- mance improvements in real-world web sites.