What is Web Performance?

Web performance encompasses the speed and responsiveness of a website as measured by metrics like Largest Contentful Paint (LCP), First Contentful Paint (FCP), Time to First Byte (TTFB), Total Blocking Time (TBT), and Cumulative Layout Shift (CLS). These Core Web Vitals directly impact Google search rankings and user experience.

Page builders and CMSs typically score poorly on performance benchmarks. WordPress sites pass Core Web Vitals only 43% of the time on mobile, while Squarespace averages a Lighthouse score of 31 on mobile. By contrast, static sites built with frameworks like Astro routinely achieve perfect 100 scores.

Performance optimization often drives site migration decisions, as the performance gap between CMS-hosted sites and static sites continues to widen.