performance

Images typically account for 50%+ of a page's total weight, making format selection, responsive sizing, lazy loading, and compression the highest-impact performance wins for most websites.

Lazy loading defers the loading of non-critical resources until they are needed, reducing initial page weight and improving Time to Interactive through native attributes, Intersection Observer, and dynamic imports.

Core Web Vitals are Google's three key metrics (LCP, INP, CLS) that measure real-world user experience for loading speed, interactivity, and visual stability, directly impacting search rankings.