Next.js 16.4

Next.js 16.4 formalizes Cache Components as the recommended programming model for all apps, enabling fast initial loads for personalized pages, instant client navigations, and opt-in, composable caching. New projects created with create-next-app enable cacheComponents and partialPrefetching by default, and existing apps get agentic tooling to assist migration. The release also ships general performance improvements - lower dev memory and disk usage, faster compile times, smaller production bundles - and updates to React 19.3.

Technically, Cache Components let you mark component boundaries for caching (a component-level "use cache" model), with cacheLife and pluggable server/browser caching. New controls include ensureStatic (levels: navigation, prefetch, shell) to guarantee a route’s shell, prefetch, or full navigation stays fully static, and navigation() / prefetch() APIs to exclude or defer portions of a page from prefetching so heavy data (e.g., an email thread) isn’t fetched until actual navigation. The release also adds an agent-driven next upgrade flow and Skills to automate version-specific refactors for adopting Cache Components. These changes aim to close previous performance/cost gaps and make the new model safe and practical for greenfield and existing apps alike.