Summary

Next.js 10.2 focuses on developer and runtime performance improvements, accessibility, routing flexibility, and automatic font optimization. The release expands webpack 5 usage for apps without a custom webpack config, adds a new has matcher for rewrites/redirects/headers, and inlines Google Fonts CSS at build time to improve FCP/LCP.

Key Points

• Upgrade: run npm i next@latest to get the release.
• Webpack 5 rollout: apps without a custom webpack config now use webpack 5 by default, gaining improved disk caching, deterministic output, better tree-shaking, and faster subsequent builds (Vercel observed up to ~63% speedup).
• Faster dev experience: Fast Refresh prioritized (100–200ms faster refreshes) and next dev startup improved up to ~24% after first run.
• Accessibility: client-side route changes are announced to screen readers by default (page name found by h1, then document.title, then pathname).
• Routing enhancements: rewrites, redirects, and headers support a new has property to match headers, cookies, or query strings for conditional routing.
• Automatic Webfont Optimization: Google Fonts are automatically inlined at build time to reduce render-blocking requests and improve Core Web Vitals; support for more providers and loading controls is planned.
• Note for custom configurations: if you use a custom webpack config, follow the migration docs to enable webpack 5 and validate behavior.

Actionable Checklist for Engineers

• Run npm i next@latest in your project and test locally.
• If you have a custom webpack configuration, read the webpack 5 migration docs and opt-in accordingly.
• Audit redirects/rewrites that could benefit from the has matcher (headers/cookies/query).
• Verify font loading and Core Web Vitals after automatic webfont optimization; opt out or configure if necessary.