What is website performance optimization and why does it matter for SEO and conversions?

Website performance optimization is the process of improving how quickly a website loads, responds to user interactions, and delivers content, measured against standards like Google’s Core Web Vitals: LCP (Largest Contentful Paint), CLS (Cumulative Layout Shift), and INP (Interaction to Next Paint). These are not just technical benchmarks; they are direct ranking signals in Google’s search algorithm.

For conversions, the business case is equally strong. Google’s research shows that a one-second improvement in mobile load time can increase conversions by up to 27% for retail sites. Slow pages increase bounce rates, reduce session depth, and undermine campaign ROI by delivering qualified traffic to pages that frustrate users before they convert. Performance optimization is therefore both an SEO investment and a conversion rate investment, with measurable returns on both dimensions when tracked properly.