Optimizing Core Web Vitals in Next.js

Core Web Vitals affect both user experience and search ranking. Next.js gives you the tools to score well — here's how to use them for each metric.

LCP — Largest Contentful Paint

LCP measures how fast the main content appears. Use the Next.js `<Image>` component with priority on your hero image, serve modern formats, and lean on server rendering so meaningful content arrives in the first response rather than after a JavaScript round-trip.

CLS — Cumulative Layout Shift

Layout shift happens when content jumps as the page loads. Always set width and height (or aspect ratio) on images and embeds, reserve space for dynamic content, and use `next/font` to avoid the flash and reflow that web fonts can cause.

INP — Interaction to Next Paint

• Ship less JavaScript — keep client components small and push logic to the server.
• Avoid long tasks on the main thread; break up heavy work.
• Defer non-critical scripts and third-party embeds.
• Use server components for anything that doesn't need interactivity.

Measure, don't guess

Use Lighthouse for lab data and the Search Console Core Web Vitals report for real-user field data. Field data is what Google actually ranks on, so watch it after every significant change.

KitCraft templates are built for performance — optimized images, `next/font`, minimal client JavaScript, and server rendering — so you start from a strong Core Web Vitals baseline.