Problem Statement
Explain dynamic imports and lazy loading in Next.js and when you should use them.
Explanation
Use dynamic imports with next/dynamic for components that aren't needed immediately, like modals, charts, or heavy third-party libraries, by wrapping them in dynamic function which returns a lazy-loaded component that splits the code into a separate bundle.
Configure loading fallbacks with the loading option to show spinners or skeletons while the component loads, disable SSR with ssr false for client-only components that depend on browser APIs, and use suspense true to wrap in React Suspense boundary for better loading state composition.
Dynamic imports are perfect for route-based code splitting for large page sections not visible on initial load, conditionally loaded features based on user permissions or feature flags, heavy libraries like rich text editors or data visualization that most users won't need, and reducing the critical path bundle size for faster initial page loads.
Avoid over-splitting small components as the overhead of additional HTTP requests can outweigh bundle size savings, and ensure you're measuring actual performance improvements with Core Web Vitals rather than optimizing blindly.