O'Reilly logo

Web Performance in Action: Building Fast Web Pages by Jeremy L. Wagner

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

Chapter 4. Understanding critical CSS

This chapter covers

  • Understanding critical CSS and the problem that it solves
  • Understanding how critical CSS works
  • Using critical CSS in your projects
  • Knowing the benefits of critical CSS before and after implementation

With some CSS optimization techniques under your belt, it’s a good time to learn an advanced CSS optimization task that speeds up the rendering of a page by prioritizing rendering of above-the-fold content. This technique is called critical CSS.

4.1. What does critical CSS solve?

Critical CSS is an optimization task that enables you to rethink how CSS is loaded by the browser by prioritizing the CSS for above-the-fold content ahead of below-the-fold content. When done properly, the ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required