Vercel has released Next.js 16.3, which the team calls its biggest update to the React framework since Next.js 16.0 came out last November. The headline change is memory: Turbopack now uses up to 90% less RAM when running next dev, a fix aimed at the out-of-memory crashes that end in a Node.js “FATAL ERROR,” as The Register put it.
The savings come from two features now on by default: disk caching for dev, first introduced in 16.1, and memory eviction, which moves unused artifacts to disk. In Vercel’s tests after compiling 50 routes, the nextjs.org project fell from about 4,600 MB to 840 MB, and the vercel.com dashboard from 21.5 GB to 2 GB.
Disk caching now also works with next build. Vercel says cached builds of nextjs.org dropped from 21 seconds to 9.2 seconds, and it has seen some projects build 5.5x faster on CI. Projects can also use TypeScript 7, the native port released last month, for type checking during builds by bumping their local dependency.
On the runtime side, Next.js replaced web streams with native Node.js streams in the App Router rendering layer. In Vercel’s benchmarks, apps handled up to 22% more requests under load with no code changes.
Error handling gets a new tool as well. React error boundaries in Next.js previously interfered with code that called notFound or redirect, could only reset client-side state and couldn’t retry Server Components that failed while rendering. The new catchError API defines a custom boundary that leaves notFound and redirect alone and passes a retry() function that refetches the boundary’s children, including Server Components.
Other additions include version-matched docs for AI coding agents through an AGENTS.md block, fewer prefetch requests, optional reuse of immutable static assets across deploys, built-in glob imports and root params. An opt-in Instant Navigations suite adds devtools that flag slow navigations, partial prefetching and a Playwright test helper. An experimental Rust-based React Compiler is also included.
Developers can upgrade by installing the latest next package from npm.
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