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Rspack 2.0 Ships with ESM Core, 100% Build Speed Gains, and 192-to-1 Dependency Cut

ByteDance's Rust-based webpack alternative Rspack 2.0 cuts dependencies from 192 to 1, shrinks install size to 1.4 MB, and doubles build speed over version 1.0.

Rspack 2.0 from ByteDance delivers a pure ESM core, up to 100% faster builds than version 1.0, and a drastic reduction from 192 dependencies to just 1, positioning it as a serious webpack alternative with a stronger supply-chain security posture.

ByteDance's Rust-based JavaScript bundler Rspack has released version 2.0, shipping a pure ESM core, experimental React Server Components support, and dramatic reductions in dependency count and install size. The project has grown from roughly 100,000 weekly downloads around its 1.0 release to more than 5 million.

Performance and Size

Build performance is approximately 10% faster than Rspack 1.7 and up to 100% faster than 1.0. On a benchmark project, production builds with persistent cache dropped from 5.6 seconds to 1.4 seconds, while hot module replacement fell to 118 milliseconds. Cache reuse for the SWC minimizer improves build performance by around 50% on cache hits, and memory usage drops more than 20% when cache is enabled.

The most striking change may be the dependency reduction. The core package went from 192 dependencies down to 1, and its install size shrank from 15 MB to 1.4 MB. One Hacker News commenter called it "a shift in philosophy, not just a benchmark" and "a stronger supply-chain stance than most bundlers take at this stage."

ESM-First Architecture

Rspack 2.0 is now published as a pure ESM package with its CommonJS build removed. Because Node.js v20.19 and later can load ESM via require(), most projects using the JavaScript API need no code changes. The release adds support for import.meta.dirname and the stage-3 import defer proposal, alongside improved ESM library builds. Tree shaking improves with side-effect-free function analysis enabled by default in production.

Upgrade Notes

Developers upgrading from 1.x should note that Rspack 2.0 requires Node.js 20.19+ or 22.12+, dropping Node.js 18. The experiments.css option has been removed. The team recommends bumping rspack, @rspack/core, and @rspack/cli together to ^2.0.0. The 1.x line will continue receiving critical fixes, though new development is focused on 2.x.

Rspack competes with webpack, Vite's Rolldown, and Turbopack, leaning on its roughly 90% webpack API compatibility as a migration advantage. It remains open-source under the MIT license.