The Ultimate Guide to Core Web Vitals in 2026

LCP measures how long it takes for the largest piece of content (usually a hero image or text block) to render on the screen. A good LCP is under 2.5 seconds. To improve LCP, prioritize critical rendering paths, defer non-critical JavaScript, and use modern image formats like WebP or AVIF served via a CDN.

Replacing FID (First Input Delay), INP measures the overall responsiveness of a page to user interactions, such as clicks or taps. An INP under 200 milliseconds is considered good. Optimizing INP requires breaking up long JavaScript tasks in the main thread so the browser can respond to user inputs immediately, without freezing.

"2. Interaction to Next Paint (INP): The Interactivity Metric— this is the kind of insight that separates high-performing teams from the rest."

— Nexa Team

📷  2. Interaction to Next Paint (INP): The Interactivity Metric

CLS measures unexpected layout shifts that happen as a page loads—like when you try to click a button, but an ad loads and pushes the button down. A good CLS score is less than 0.1. To fix CLS, always include width and height attributes on images and videos, and reserve space for dynamic content like ads or embeds so they do not push other content around.

Beyond SEO, these metrics directly impact conversion rates. Amazon famously found that every 100ms of latency cost them 1% in sales. A fast, stable site builds trust and keeps users engaged. Regularly auditing your site with tools like Google PageSpeed Insights and Lighthouse is the best way to ensure you maintain high performance.

"Why Core Web Vitals Matter for Revenue— this is the kind of insight that separates high-performing teams from the rest."

— Nexa Team