Next.js 16

Next.js 16 brings a host of new features and enhancements aimed at improving performance, developer experience, and flexibility. The release introduces Cache Components, which leverage Partial Pre-Rendering (PPR) for more efficient caching by using a "use cache" directive. This allows developers to opt-in explicit caching, offering a more predictable full-stack application framework. The stable release of Turbopack, now the default bundler, promises faster builds and refreshes, significantly enhancing development speed. File system caching, still in beta, further accelerates compile times, especially in larger apps.

Next.js 16 also features the Next.js DevTools MCP, an AI-assisted debugging tool that provides contextual insights into routing, caching, and rendering behaviors. The new proxy.ts file replaces middleware.ts, clarifying network boundaries while running on the Node.js runtime. Logging has been improved to offer detailed insights into build and development request times.

Routing and navigation have been revamped to include layout deduplication and incremental prefetching, which optimize network transfer sizes and improve page transitions. The update also introduces new caching APIs like revalidateTag() and updateTag(), offering more explicit control over cache behavior. The integration of React 19.2 features, including View Transitions and useEffectEvent(), further enhances the framework's capabilities.

Breaking changes include updates to async parameters and default settings for next/image, among others. Deprecated features like middleware.ts and the single-argument revalidateTag() have been replaced or updated to improve security and performance. The release also includes performance optimizations for next dev and next start commands, along with support for Node.js native TypeScript in next.config.ts.