Next.js 13 → Next.js 15

Migrating from Next.js 13 to Next.js 15. Coming from 13 you also absorb the 14 changes (stable App Router, Server Actions, Turbopack dev), so plan for a slightly larger surface.

Should you upgrade directly?

Yes, directly to 15, but budget for the 14-era changes too: the App Router and Server Actions stabilized in 14, so confirm those are sound before layering on the 15 async-API and caching work.

Key differences

• Async request APIs: cookies/headers/draftMode/params/searchParams return Promises.
• fetch() and GET Route Handlers are no longer cached by default.
• React 19 in the App Router; next/font is built in.
• Stable App Router and Server Actions plus Turbopack dev landed in 14 — verify these first.

Files and patterns to inspect

• Pages/layouts reading params or searchParams synchronously.
• Server code calling cookies(), headers(), or draftMode() without await.
• fetch() calls and GET Route Handlers relying on default caching.
• Imports of the standalone @next/font package.
• next.config.js options deprecated between your version and 15.

Pre-migration checklist

• Green test suite and successful next build on the current version
• Lockfile committed; dependencies audited for React 19 / Next 15 support
• A dedicated upgrade branch

Related paths

• Next.js 14 to Next.js 15 Migration Guide — Upgrade path to same target
• Next.js 15 to Next.js 16 Migration Guide — Next step forward
• Migrate Next.js Pages Router to App Router — Adjacent migration
• Upgrade to Next.js 15 — Upgrade path to same target
• Upgrade to Next.js 16 — Related version path
• Fix Next.js Build Errors — Related workflow

Official sources

• Next.js 15 — nextjs.org (reliability 98%)
• Upgrading: Version 15 — nextjs.org (reliability 98%)

Frequently asked questions

Can I go straight to Next.js 15 from 13?

Coming from 13 you also absorb the 14 changes (stable App Router, Server Actions, Turbopack dev), so plan for a slightly larger surface.