Rolldown

Rust-based JavaScript and TypeScript bundler that combines Rollup-compatible APIs with esbuild-level performance. Handles tens of thousands of modules in seconds while offering a familiar plugin ecosystem, built-in transforms, minification, CSS bundling, and code splitting.

Rolldown is developed by the team behind Vite and serves as the unified bundler powering Vite 8 and later. It delivers notable speed gains over traditional Rollup and esbuild setups for large module graphs, with similar performance to esbuild on benchmarks while keeping full Rollup compatibility.

Key features:

• Rollup-compatible API and plugin ecosystem
• Built-in TypeScript, JSX, and syntax lowering via Oxc down to ES2015
• Native CJS and ESM interop without extra plugins
• Define, inject, platform presets, and module resolution aligned with esbuild and Node semantics
• CSS bundling and manual code splitting
• CLI, config file, and JavaScript API with watch mode

Useful for bundling web apps and libraries when build speed matters. Integrates with Vite for dev server, HMR, and production builds, or runs standalone via tsdown for library packaging. Fits into existing Rollup-based pipelines with minimal config changes.