Rolldown 1.0 Launches: Up to 30× Faster Than Rollup and 20M Weekly Downloads

On May 7 the Rolldown team announced the stable 1.0 release, a Rust‑based rewrite of the JavaScript bundler that aims to be a drop‑in replacement for Rollup.

Rolldown is now the default underlying engine of Vite 8, meaning any project using the latest Vite automatically runs on Rolldown. The team claims performance improvements of 10‑30× over Rollup, comparable to esbuild.

What is Rolldown?

Rolldown is a Rust‑implemented JavaScript bundler led by VoidZero, the company founded by Vue creator Evan You, with backing from the Vite core team. Its primary goal is speed, addressing Rollup's performance bottlenecks on large projects while preserving Rollup's API and plugin ecosystem.

In a single sentence, Rolldown is the “Rust version of Rollup,” allowing developers to keep existing plugins and configurations while gaining native‑speed builds.

Performance Numbers

The official benchmark reports a 10‑30× speed advantage, with larger projects seeing a bigger gap. Real‑world case studies show:

Ramp: build time reduced by 57%.

Mercedes‑Benz.io: build time reduced by up to 38%.

Beehiiv: build time reduced by 64%.

These are production workloads with real traffic, confirming Rolldown’s effectiveness in practice.

Weekly downloads have already surpassed 20 million, a rapid adoption rate for a front‑end tool within two years of its first public version.

Zero Migration Cost

Rolldown guarantees full compatibility with Rollup plugins, meaning existing Rollup plugins can run unchanged. Vite 8’s plugin ecosystem works out‑of‑the‑box with Rolldown.

The bundler also introduces a Hook filters mechanism that lets plugins declare the files they care about, preventing unnecessary JavaScript callbacks and keeping hot paths fast.

Integration Timeline with Vite

April 2024: Rolldown 0.10.1 released publicly.

December 2024: 1.0.0‑beta.1 released.

May 2025: rolldown-vite technical preview.

December 2025: Vite 8 beta sets Rolldown as the default bundler.

January 2026: Rolldown 1.0 RC.

March 2026: Vite 8 stable.

May 2026: Rolldown 1.0 stable.

Thus Vite 8 has been using Rolldown as its default engine for over two months before the official 1.0 release.

For Vite users the switch is invisible—upgrading Vite automatically adopts Rolldown, and large projects experience noticeably faster builds.

Unique Capabilities

Beyond speed and compatibility, Rolldown adds features not present in Rollup:

Fine‑grained code splitting : Webpack‑style chunk rules using regex allow developers to isolate modules into separate chunks. Framer used this to cut chunk count by 67%.

Aggressive dead‑code elimination : Supports @__PURE__ and @__NO_SIDE_EFFECTS__ annotations, constant inlining, and TypeScript const‑enum inlining, plus a lightweight compression mode for clean output.

Built‑in plugins : Implements functionality such as replacePlugin and esmExternalRequirePlugin in Rust, removing the need for JavaScript plugin chains.

Native MagicString (experimental) : A Rust drop‑in replacement for Rollup’s MagicString library, accelerating source‑code transformations.

Using Rolldown Directly

Rolldown can be used outside Vite with the same installation command as Rollup: npm install -D rolldown A minimal configuration looks like:

import { defineConfig } from 'rolldown'
export default defineConfig({
  input: 'src/main.ts',
  output: { dir: 'dist' }
})

Build with npx rolldown -c. The API mirrors Rollup, making migration straightforward.

Upcoming Features

Rolldown 1.0 is stable, but several capabilities remain experimental, including watch mode, native MagicString, and lazy‑barrel optimization. Users relying on these should monitor their stability before production use.

Writing custom plugins still requires JavaScript, and debugging the Rust internals demands Rust expertise, which may raise the barrier for tool maintainers.

Finally, Rolldown’s rapid adoption is tightly coupled with the Vite ecosystem; while this provides immediate real‑world validation, it also means Rolldown’s future development pace is closely linked to Vite’s roadmap.