Core Web Vitals

Core Web Vitals are a subset of Google's Web Vitals initiative, focusing on three critical aspects of user experience: loading performance (LCP), interactivity (INP), and visual stability (CLS). These metrics are confirmed Google ranking factors and directly impact how your pages perform in search results.

Largest Contentful Paint (LCP) measures how quickly the largest visible element on a page loads, with a target of under 2.5 seconds. Interaction to Next Paint (INP) replaced First Input Delay (FID) in 2024 and measures the responsiveness of a page to user interactions throughout the entire page visit, with a target of under 200 milliseconds. Cumulative Layout Shift (CLS) measures unexpected layout shifts during the page's lifecycle, with a target score below 0.1.

Improving Core Web Vitals requires a combination of front-end optimization techniques. For LCP, this includes optimizing images, implementing lazy loading, and reducing server response times. For INP, it involves minimizing JavaScript execution time, breaking up long tasks, and optimizing event handlers. For CLS, you need to set explicit dimensions on images and embeds, avoid injecting content above existing content, and use CSS containment where appropriate.