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Next.js 16.4 • Cache Components by default in new apps • Static output guarantees and more control over prefetching • Agent-guided upgrades and feedback • 20–25% smaller Turbopack disk cache • Faster development and smaller bundles nextjs.org/blog/next-16-4

Starting with Next.js 16.4, we're excited to recommend Cache Components as the best choice for every Next.js application. All new apps made with 𝚌𝚛𝚎𝚊𝚝𝚎-𝚗𝚎𝚡𝚝-𝚊𝚙𝚙 have Cache Components enabled by default.

The new 𝚎𝚗𝚜𝚞𝚛𝚎𝚂𝚝𝚊𝚝𝚒𝚌 API lets you mark routes that should produce a static response when they're first loaded, explicitly prefetched with a link, or fully rendered during a navigation. This prevents accidental request-time rendering for static pages.

The new 𝚗𝚊𝚟𝚒𝚐𝚊𝚝𝚒𝚘𝚗() API lets you exclude parts of a page from being rendered during a prefetch. Use it to prerender only the most meaningful UI ahead of time, and defer more expensive secondary content until an actual user navigation.

A new CLI command helps agents upgrade your Next.js apps: 𝚗𝚙𝚡 𝚗𝚎𝚡𝚝@𝚌𝚊𝚗𝚊𝚛𝚢 𝚞𝚙𝚐𝚛𝚊𝚍𝚎 --𝚊𝚐𝚎𝚗𝚝=𝚕𝚊𝚝𝚎𝚜𝚝 It gives your agent any guides, codemods, and verification steps needed, all specific to your version of Next.js.

Coding agents encounter framework errors and workarounds we may not otherwise see. The experimental 𝚊𝚐𝚎𝚗𝚝𝙵𝚎𝚎𝚍𝚋𝚊𝚌𝚔 workflow drafts reports for you to review before sending, helping us improve Next.js based on the problems coding agents encounter.

Turbopack now does less work and produces smaller output: a 20–25% smaller disk cache, server updates compiled only when needed, and smaller production bundles. New experimental features let apps load imports on demand, remove stale cache data, and run plugins in worker threads.

Turbopack Bundle Analyzer now surfaces large client routes, snapshot diffs, and critical render-path modules. Use the 𝚗𝚎𝚡𝚝-𝚋𝚞𝚗𝚍𝚕𝚎-𝚘𝚙𝚝𝚒𝚖𝚒𝚣𝚎𝚛 skill with your coding agent to reduce what reaches the browser. skills.sh/vercel/next...