Turbopack's chunker decides which code each page downloads. The September 3 post explains that decision: shared code lands in shared chunks, routes carry only their own bytes, and Next 16.3 shipped experimental knobs for apps whose layouts defeat the defaults.

What it changes for you

  • You can reason about the bundle graph instead of staring at a stats file: vendor code shared, page code page-local.
  • The experimental flags matter at the tails: huge shared components and long import chains where default splitting leaves bytes unsent.
  • Deployment gets simpler, not harder: chunks stay plain files your CDN caches.
Chunking is web performance with a fancier name: send only the bytes this page needs.

For static exports the effect shows in one number: transfer size per route. Measure yours before and after any tooling change; the winner is still, as ever, not loading what the page never calls.