Open-source bundlers and build tools

9 bundlers and build tools whose code is public under an OSI-approved license, rated for privacy with evidence. Picks first, then by score.

1. esbuild Grade B

   JavaScript and TypeScript bundler and minifier written in Go, with a command-line tool and APIs for JavaScript and Go.

   MIT. Source code

2. Rolldown Grade B

   JavaScript and TypeScript bundler written in Rust with a Rollup-compatible API, developed as the bundler for Vite.

   MIT. Source code

3. Rollup Grade B

   Module bundler for JavaScript that compiles ES modules into bundles for libraries and applications, with tree shaking and a plugin API.

   MIT. Source code

4. Vite Grade B

   Frontend build tool with a fast development server using native ES modules and hot module replacement, and a production bundler for web applications.

   MIT. Source code

5. Bun Grade C

   JavaScript runtime, package manager, test runner and bundler in a single executable, built on JavaScriptCore and written in Zig.

   MIT, with the statically linked JavaScriptCore under LGPL-2. Source code

6. Parcel Grade D

   Zero-configuration bundler for web applications that builds JavaScript, CSS, HTML and other assets, with a Rust-based compiler and built-in development server.

   MIT. Source code

7. Rspack Grade D

   JavaScript bundler written in Rust that is compatible with the webpack configuration and plugin API, developed by the ByteDance web infrastructure team.

   MIT. Source code

8. webpack Grade D

   Module bundler for JavaScript applications that builds a dependency graph and packages code and assets into bundles, extensible through loaders and plugins.

   MIT. Source code

9. Turbopack Grade D

   Incremental bundler written in Rust and built into Next.js, used by the Next.js development server and production builds.

   MIT, developed in the Next.js repository. Source code

Compare all 9 bundlers and build tools, open source or not.