Core Web Vitals in 2025: A Practical Guide to LCP, INP and CLS

Core Web Vitals are Google’s user-experience metrics for the web. They form part of the page experience signals and, more importantly, reflect how your site feels to real people.

Largest Contentful Paint (LCP): loading

LCP measures how long it takes for the biggest visible element, usually a hero image or headline, to appear. Aim for 2.5 seconds or less.

• Optimise and correctly size the hero image; do not lazy-load it.
• Use fast hosting, caching and a CDN.
• Remove render-blocking scripts and styles.

Interaction to Next Paint (INP): responsiveness

INP measures how quickly the page responds visually to clicks, taps and key presses. Aim for 200 milliseconds or less.

• Reduce heavy JavaScript and long tasks.
• Delay or remove unnecessary third-party scripts.

Cumulative Layout Shift (CLS): stability

CLS measures unexpected movement of content as the page loads. Aim for 0.1 or less.

• Set width and height on images and video.
• Reserve space for ads, embeds and banners.
• Avoid inserting content above existing content after load.

Where to measure

Use field data from Search Console and PageSpeed Insights, which reflects real visitors, and lab tools like Lighthouse to find causes. Fix the templates that affect the most pages first, and re-test after each change.