Next.js 15 Releases Turbopack for Dev by Default and React 19 Support
Vercel released Next.js 15, enabling the Rust-based Turbopack bundler by default for local development with up to 96% faster code startup.
Verified State Diff
Comparison Mode:
- Previous State
Development server used Webpack by default; headers() and cookies() were synchronous APIs.
+ Verified New State
Turbopack default dev bundler; headers(), cookies(), and params are now asynchronous Promises.
Impact & Verification Analysis
WHO IS AFFECTED
Full-stack React developers, frontend engineering teams, and Next.js production deployments.
WHY IT MATTERS
Dramatically speeds up local developer iteration and standardizes async request handling for React Server Components.
Full Fact Overview
Next.js 15 introduces async Request APIs (cookies, headers, params), React 19 support with Actions, and non-blocking Server Components caching.
Multi-Source Evidence Chain (1)
TRACKED ENTITY
Explore all historical Next.js changes