Everything new in Next.js 16

Next.js 16 introduces Cache Components for explicit caching control, Turbopack as the default bundler (2-5× faster builds), and refined caching APIs. The release includes proxy.ts (renamed from middleware.ts), improved logging with detailed build breakdowns, React 19.2 support with useEffectEvent and View Transitions, and enhanced routing with layout deduplication and incremental prefetching. DevTools MCP integration enables AI-powered debugging, while Build Adapters API allows custom deployment pipelines. The update focuses on predictability, performance, and developer experience rather than major architectural changes.