Core Web Vitals / SEO

Core Web Vitals are a set of user experience metrics introduced by Google to measure the speed, responsiveness and visual stability of a webpage. These metrics are part of Google’s overall page experience signals and directly influence search rankings. The goal is to ensure that websites deliver smooth, fast and reliable experiences across all devices, especially mobile.

There are three primary Core Web Vitals:

Largest Contentful Paint (LCP) measures loading performance. It tracks how long it takes for the largest content element on the page—such as a banner image or main heading—to become visible.

First Input Delay (FID) measures interactivity. It reflects how quickly a page responds when a user first tries to interact, for example by clicking a link or tapping a button.

Cumulative Layout Shift (CLS) measures visual stability. It detects unexpected layout shifts that occur while the page is loading, which can lead to a frustrating user experience.

Each metric has target thresholds defined by Google. A good user experience means LCP should occur within 2.5 seconds, FID should be less than 100 milliseconds and CLS should remain below 0.1. Site owners can monitor and optimise these metrics using tools like Google PageSpeed Insights, Lighthouse and Search Console. Improving Core Web Vitals involves practices such as optimising images, reducing third-party scripts, enabling lazy loading and improving server response times. For marketers and developers alike, these metrics are not just technical checkboxes—they represent a commitment to fast, user-first design that improves engagement and boosts visibility in search.