Upgrade checklists / Product releases
Next.js 16.4.3 Upgrade Checklist: Fonts, Proxy & Traces
Published October 31, 2026 · Source-linked checklist
This checklist targets applications already on the Next.js 16.4 stable branch. The publisher describes 16.4.3 as a bug-fix backport, so it should not be treated as containing every pending canary feature.
Changes worth checking
The release addresses extensionless Google Fonts URLs, app-page runtime loading in proxy.ts, request trace continuity and standalone React loading. It also reverts a Turbopack loader-invalidation change.
Suggested validation
- Save your lockfile and current deployment artifact. Install the exact target with
npm install --save-exact [email protected]; check the project's React peer dependencies. - Build and smoke-test routes using Google Fonts. If you have custom loaders, change an imported file during development and check that output refreshes.
- Exercise proxy-handled routes and inspect request traces. For standalone deployments, start the generated server and test a real page before rollout.
These are suggested checks, not tests performed on your application. Review the complete source and any skipped releases before deploying. Keep the previous lockfile and deployment artifact available for rollback.