Rslib vs Turbopack

Rslib is a free, open-source tool for developing JavaScript packages and UI component libraries. Based on Rsbuild and powered by Rspack, it integrates Rust-based tools including SWC and Lightning CSS. It supports bundle and bundleless build modes and outputs ESM, CJS, UMD, Module Federation, and IIFE formats. Framework integrations support component libraries for React, Vue, Svelte, and Solid. Rslib can generate TypeScript declaration files, including isolated declarations, though declaration generation is not enabled by default. Plugin support includes Rsbuild, Rspack, and webpack plugins. Its development integrations include Rstest for testing, Storybook for component development, Rspress for documentation and component previews, and Rsdoctor for build analysis. The quick-start guide lists Node.js, Deno, and Bun as runtime options, while Rslib v1 requires Node.js 20.19+ or 22.12+. It is available for API, Linux, macOS, web, and Windows, and is released under the MIT license.

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.