Turbopack

Turbopack is the build engine built by Vercel. In 2025, it is Stable in Next.js and powers the fastest dev server in the ecosystem.

When to Use

• Next.js: It's the default dev engine (next dev --turbo).
• Scale: Designed for monorepos with thousands of pages.

Core Concepts

Incremental Computation

Turbopack never does the same work twice. It caches function results at a granular level (the "Function Level Caching").

Lazy Bundling

It only bundles the dynamic imports and pages you actually visit.

Request Level Compilation

Compiles code only when a request hits the server.

Best Practices (2025)

Do:

• Use --turbo: Enable it in Next.js for instant HMR.
• Trust the Cache: Turbopack handles invalidation correctly.

Don't:

• Don't configure it manually: In 2025, it's mostly configured via framework adapters (Next.js).

References

• Turbopack Documentation