Style Recalculation Secrets They Don’t Want You To Know

A presentation at CSS Day in in Amsterdam, Netherlands by Patrick Brosset

A deep dive into style recalculations and CSS selector performance

How do browsers actually recalculate styles when webpages change? Can the way you write CSS impact the speed of the recalculation process?

In this talk, we’ll go through the details of how browser engines react to DOM changes and apply styles to the page again. We’ll also take a look at examples and case studies to make things practical. And finally, we’ll review developer tools that will help you investigate style performance bottlenecks.