Rspack vs SWC

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.

SWC is a free, extensible Rust-based platform for tools that compile and bundle JavaScript and TypeScript. It transforms modern JavaScript and TypeScript into code intended for major browsers, and supports minification, WebAssembly transforms, and custom plugins. Its core API parses ECMAScript, TypeScript, and Flow syntax; the documentation describes that API as mainly useful to build-tool authors. Integrations include webpack, Rspack, and Jest, while Next.js, Parcel, and Deno are among the tools named as users. A WebAssembly module can transform code synchronously inside a browser. SWC can be installed as prebuilt binaries or built from source, with packages documented for npm, Yarn, pnpm, Bun, and Deno. The site states that it is 20x faster than Babel on one thread and 70x faster on four cores. The bundling documentation says that feature will be dropped in v2 and recommends SWC-based bundlers instead. It also warns that its polyfill usage mode is less efficient than Babel for certain dynamically computed property expressions.