Introduction to Next.js Performance

Next.js is renowned for its performance benefits, primarily due to features like server-side rendering (SSR ), static site generation (SSG), and automatic code splitting. However, to truly achieve blazing fast performance, developers need to go beyond the basics and implement advanced optimization techniques.

Image Optimization

Using `next/image` Component

The `next/image` component is a powerful tool for optimizing images in Next.js. It automatically handles lazy loading, responsive sizing, and modern image formats like WebP, significantly reducing page load times.

External Image Optimization

For images served from external sources, consider using image CDNs or services that can optimize and deliver images efficiently. This offloads the processing from your server and ensures fast delivery globally.

Font Optimization

Self-Hosting Fonts

Self-hosting fonts can prevent render-blocking issues and improve First Contentful Paint (FCP). Use `next/font` to automatically optimize your fonts, including preloading and subsetting.

Font Display Strategies

Implement `font-display: swap` or other strategies to control how fonts are loaded and displayed, preventing invisible text during font loading (FOIT) and ensuring a better user experience.

Code Splitting and Lazy Loading

Dynamic Imports

Next.js supports dynamic imports for components, which allows you to lazy-load parts of your application only when they are needed. This reduces the initial bundle size and improves load performance.

Component-Level Lazy Loading

Apply lazy loading to large components or libraries that are not critical for the initial page load. This ensures that users only download the code they need for the current view.