Rslib vs Rspack

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.

Rspack is a free, open-source bundler for web projects, built with Rust and TypeScript. Its parallelized architecture supports parallel builds, while incremental compilation is used to improve hot module replacement. Rspack updates the webpack API with the aim of supporting webpack replacement, but it does not promise full API compatibility; it prioritizes commonly used APIs and adds others based on user needs. It works with almost all community loaders, and over 85% of the 50 most downloaded webpack plugins can be used with it or have an alternative. Built-in capabilities include code splitting, tree shaking, asset management, a development server, SWC, Lightning CSS, and a JavaScript build API. Documented integrations cover React, React Server Components, Preact, Vue, Next.js, Node.js applications, NestJS, Solid, Svelte, and Rstest. Custom plugins and loaders can be written in JavaScript or Rust. Rspack 1.0 was released in August 2024 and is described as production-ready. It is available for Linux, macOS, and Windows, as well as web and self-hosted environments. The software is released under the MIT license; questions can be directed to Discord or GitHub Discussions.