Rslib
6.8#3 in javascript build toolsFree planFree planWebAPILinuxmacOS
VisitRslib vs tsdown
What both publish
| Fact | Rslib | tsdown |
|---|---|---|
| Build engine | Rslib is based on Rsbuild and uses Rspack, with SWC and Lightning CSS among the Rust-based tools it integrates. | tsdown is built on Rolldown, a Rust-based bundler. |
| License | Rslib is free and open source software released under the MIT license. | The project website states that tsdown is released under the MIT License. |
| Maker | The official site identifies ByteDance Inc. in its copyright notice. | The project credits VoidZero Inc. and contributors. |
| Output formats | Rslib supports ESM, CJS, UMD, Module Federation, and IIFE output formats. | It supports ESM, CJS, IIFE, and UMD output formats. |
| Purpose | Rslib is an Rsbuild-based tool for developing JavaScript libraries and UI component libraries. | tsdown is a bundler designed for building TypeScript and JavaScript libraries. |
| Runtime requirement | Rslib v1 requires Node.js 20.19+ or 22.12+. | The guide requires Node.js ^22.18.0, ^24.11.0, or >=26.0.0 to run tsdown and says Bun and Deno support is experimental. |
Rslib plans
- Free and open sourceFree
tsdown plans
No prices published.
Pick Rslib if…
Rslib is for developers building JavaScript packages or component libraries across supported UI frameworks. It can fit projects that need multiple output formats and integrations with testing, documentation, or component-development tools.
Pick tsdown if…
You want what its maker publishes above — check its page for the details.