Next.js 16 introduces major performance improvements with Turbopack as the default bundler, delivering up to 10x faster Fast Refresh and 2-5x faster production builds. The release features optimized routing with layout deduplication and incremental prefetching, new Cache Components using Partial Pre-Rendering for instant navigation, and React 19.2 integration with the stable React Compiler. New caching APIs like updateTag() provide finer control over content freshness, while Model Context Protocol integration enhances AI-assisted debugging capabilities.