Core Web Vitals Optimization: The Complete Guide 2025

Understanding and Optimizing Core Web Vitals

Core Web Vitals are essential ranking factors that Google uses to evaluate user experience. The three main metrics are Largest Contentful Paint (LCP), First Input Delay (FID), and Cumulative Layout Shift (CLS).

LCP measures loading performance. A good LCP score is under 2.5 seconds. Optimize images, implement lazy loading, and use a CDN to improve this metric.

FID measures interactivity. Users expect your site to respond to their inputs within 100 milliseconds. Minimize JavaScript execution time and break up long tasks.

CLS measures visual stability. Unexpected layout shifts frustrate users. Always specify image dimensions and avoid inserting content above existing content.