What is rsbuild?

Rsbuild is a build tool for web applications, the software that takes your raw JavaScript, TypeScript, CSS, and other source files and turns them into an optimized bundle that browsers can load. Think of it as the engine that runs under the hood when you press "build" in a web project. The problem it solves is complexity and speed. Setting up a build pipeline from scratch involves configuring a bundler (the tool that combines files together), handling different file types, and ensuring the output works across browsers. Rsbuild aims to give you fast builds with zero configuration out of the box, while still allowing full customization when you need it. Under the hood, Rsbuild is powered by Rspack, a bundler written in Rust, a programming language known for performance. It also integrates SWC and Lightning CSS, both Rust-based tools for transforming JavaScript and CSS. This Rust foundation is what makes Rsbuild notably faster than older JavaScript-based build tools. Rsbuild is framework-agnostic, meaning it is not tied to any specific UI library. The README notes support for React, Vue, Svelte, Solid, and Preact through plugins. It also has a plugin system compatible with most webpack plugins, meaning existing tooling from the broader ecosystem can typically be reused. You would reach for Rsbuild when starting a new web project that needs a fast, low-configuration build setup, or when migrating an existing webpack-based project to something faster. It is part of the broader Rstack toolchain, which includes related tools for testing, documentation, library development, and build analysis.