Pro JavaScript Performance: Monitoring and Visualization

CHAPTER 7

Runtime Performance

The last chapter explored ways to optimize web performance with JavaScript. You learned several ways to avoid having external JavaScript block the parsing of the rest of the page. We looked at the async attribute, which is new to HTML 5, and at drawing script tags with JavaScript.

You learned about the lazy load pattern, and applied it to our example's script tags, adding them to the page only after the page has loaded. We expanded that idea to apply to our CSS; lazy loading our CSS files only after the document has loaded.

You ran tests for each of these scenarios; you captured data about each one and visualized ...