Overview

Rolldown is a JavaScript bundler built in Rust, aimed at developers working in the Vite ecosystem or seeking a Rollup-compatible bundling API. Its strongest case is familiar plugin compatibility paired with built-in transforms; most application teams will be better served using it through Vite than adopting it directly.

Key features

Rolldown’s plugin API matches Rollup’s, so many existing Rollup plugins can carry over without a separate compatibility layer. That is useful for teams with established plugin-based build setups, though “most” does not guarantee every plugin will work unchanged. Community plugins published to npm appear in the Vite Plugin Registry.

Built-in TypeScript, JSX and syntax-lowering transforms, powered by Oxc, cover common compilation work without requiring separate transform plugins. The bundler also handles module resolution, ESM/CommonJS interop in mixed module graphs, define and inject options, minification, tree shaking and source maps. Manual code splitting is configurable, giving teams control over chunk organization. Experimental module types are a less dependable choice for production-critical workflows.

Rolldown provides JavaScript APIs for bundling and watching as well as building, but its build() API is experimental and may change even in patch releases. Direct use of that API therefore carries maintenance risk for projects that need a stable interface.

Install commands are provided for npm, pnpm, yarn, bun and vp. The homepage also links to an online REPL, a convenient way to explore the tool in a browser. One practical caveat is Windows file-system performance: builds can slow down, particularly when transforms run without plugins. The troubleshooting guidance also warns that direct eval can expose variables from other files to bundled code, creating a security concern if those variables contain sensitive data.

Pricing

Rolldown is free and open source under the MIT license. The Free & open source plan costs 0.00 USD per free, with no paid plans stated. There are no paid tiers to compare; the trade-off is adopting an open-source tool whose direction and development are controlled and funded by VoidZero Inc.

Platforms

Rolldown is categorized for Android, API, Linux, macOS, web and Windows. Prebuilt binaries are listed for Linux, Windows and Apple macOS architectures, with Android and other targets—including FreeBSD, OpenHarmony and Wasm/Wasi variants—also documented. Experimental or less common targets may require more care; where no prebuilt binary is distributed, users can fall back to the Wasm build or build from source.

Who it's for

Rolldown is a natural fit for Vite users who want the bundler intended to power Vite 8 and later, and for developers who value Rollup plugin reuse alongside built-in TypeScript and JSX transforms. For most applications, the recommended route is through Vite rather than direct integration. Library authors are pointed toward tsdown, while developers needing a stable direct build() API or mature experimental module-type support should look elsewhere.

Pros and cons

Pro: Rollup-compatible plugin APIs make reuse of much of an existing plugin ecosystem possible.
Pro: Built-in TypeScript, JSX and syntax lowering reduce reliance on separate transform plugins.
Pro: Mixed ESM/CommonJS graphs work without @rollup/plugin-commonjs, and manual splitting is configurable.
Con: Experimental module types and a build() API that can change in patch releases make direct use less suitable when stability is essential.
Con: Windows file-system access can slow builds, particularly when transforms run without plugins.
Con: Direct eval can expose cross-file variables, a concern when those variables hold sensitive data.

Alternatives

JavaScript Build Tools is the category to browse for a broader comparison. Choose SWC instead if you want a free, open-source Rust-based developer toolchain. Parcel is another free, open-source project, supported by contributions from companies and individuals. esbuild offers free MIT-licensed software as a native executable or WebAssembly version, with no paid tiers stated. Rspack is a free alternative released under the MIT license.

Vite is also free and open source under the MIT license; it is the natural choice for readers looking for the application-level route through which Rolldown is recommended. Oxc is a free, open-source option for readers considering the project behind Rolldown’s built-in transforms. webpack offers free, self-managed software under the MIT license. Google Closure Compiler is another free option.

Verdict

Choose Rolldown if you want a free Rust-based JavaScript bundler with substantial Rollup plugin compatibility and built-in transforms, especially as part of Vite. The main reason to hold back is the experimental surface—most notably module types and the direct build() API—along with potential Windows build slowdowns; library authors should consider tsdown instead.

	Rolldown	UglifyJS
Free plan	Yes	Yes
Free trial	No	No
Paid from	Free	Free
Open source	No	No
Platforms	Android, api, Linux, macOS, Web, Windows	api, Linux, self-hosted
Free plan	Yes	Yes
TypeScript support	Yes	—
Code splitting	Yes	—
Tree shaking	Yes	—
Source maps	Yes	Yes
Plugin API	Yes	—

Rolldown vs UglifyJS

Rolldown

UglifyJS