Core Web Vitals have been at the heart of Google's website performance evaluation since 2021. But despite their importance, many site owners do not truly understand what these metrics measure or how to optimise them.
The first metric, Largest Contentful Paint (LCP), measures the time required to display the largest visible element on the page. In practice, this is often a hero image or a main text block. Google considers a good LCP to be under 2.5 seconds. Beyond 4 seconds, it is classified as poor. Optimisation involves image compression, deferred loading of non-critical resources, and the use of a high-performance CDN.
The second metric, Interaction to Next Paint (INP), replaced First Input Delay in March 2024. It measures the page's overall responsiveness to user interactions: clicks, taps, keyboard input. A good INP is under 200 milliseconds. Sites that load massive amounts of JavaScript or execute heavy scripts at the point of interaction are the most penalised.
The third metric, Cumulative Layout Shift (CLS), measures the visual stability of the page. Have you ever clicked on a button only for the page to shift at the last moment and you end up clicking on something else? That is precisely what CLS penalises. The most common causes: images without defined dimensions, web fonts that cause a "flash" on load, dynamic content inserted above visible content.
What you need to remember is that Core Web Vitals are not a theoretical exercise. They reflect concrete problems affecting your visitors. A fast, responsive and stable site converts better. It is that simple. We integrate these metrics into our SEO and digital performance expertise. You can also request a digital audit to find out your current scores.