Rolldown vs Turbopack

Rolldown is a free, open-source JavaScript bundler written in Rust and designed as the unified bundler powering Vite 8+. Its Rollup-compatible plugin API can reuse most existing Rollup plugins. Built-in capabilities include TypeScript and JSX transforms, syntax lowering, module resolution, ESM and CommonJS interoperability, define, inject, and minification. It can handle mixed ESM and CommonJS module graphs and supports configurable manual code splitting. Install commands are provided for npm, pnpm, yarn, bun, and vp. Prebuilt binaries are listed for Linux, Windows, Apple platforms, Android, and other targets; where none is distributed, a Wasm build or building from source are options. The guide recommends using Rolldown through Vite for most applications and points library authors to tsdown. Module types are experimental, and the JavaScript build() API may change in patch releases. The troubleshooting guide says Windows file-system access can slow builds, particularly when transforms run without plugins. An online REPL is linked, along with GitHub, Discord, and contribution resources. VoidZero Inc. holds the copyrights, funds development, and directs the project; it states Rolldown remains open source and MIT-licensed.

Turbopack is an incremental JavaScript and TypeScript bundler written in Rust and built into Next.js. It supports the Pages Router and App Router for local development and is the default bundler in Next.js for basic use without configuration. It parallelizes work across CPU cores, caches results at the function level and persists them between runs. Lazy bundling processes only what the development server requests, which can reduce initial compile time and memory use. Its support includes JavaScript, TypeScript, ECMAScript, CommonJS, ESM and Babel configuration detection in Next.js 16, along with JSX, Fast Refresh and React Server Components for the App Router. CSS support includes global CSS, CSS Modules, nesting, PostCSS and Sass/SCSS, but not custom Sass functions. It also handles static image and font imports, JSON, aliases and custom extensions. Native bindings are available for Linux, macOS and Windows. Turbopack is included in Next.js with no separate price stated. It does not perform TypeScript type checking, and it does not support webpack plugins.