esbuild vs Rspack

esbuild is a free bundler for web projects, designed to improve build-tool performance while remaining easy to use. It bundles ESM and CommonJS modules, including CSS modules, with built-in support for JavaScript, CSS, TypeScript and JSX. Optimization features include tree shaking, minification and source maps; development tools include a local server, watch mode and plugins. Developers can use the command-line, JavaScript or Go interface. The recommended installation is the native executable installed with npm. An alternative WebAssembly package works across platforms, though it can be substantially slower than the native package. esbuild is MIT-licensed. It does not type-check TypeScript, and its FAQ recommends running tsc separately. The FAQ describes code-splitting support as primitive. The maintainer says the project receives periodic releases and is maintained, but active feature development is not underway. The FAQ also notes that a project primarily built by one developer may not fit organizations seeking a larger or more active community.

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.