Rolldown vs TypeScript Playground

Rolldown is a free, open-source JavaScript bundler written in Rust and designed as the unified bundler powering Vite 8+. Its Rollup-compatible plugin API can reuse most existing Rollup plugins. Built-in capabilities include TypeScript and JSX transforms, syntax lowering, module resolution, ESM and CommonJS interoperability, define, inject, and minification. It can handle mixed ESM and CommonJS module graphs and supports configurable manual code splitting. Install commands are provided for npm, pnpm, yarn, bun, and vp. Prebuilt binaries are listed for Linux, Windows, Apple platforms, Android, and other targets; where none is distributed, a Wasm build or building from source are options. The guide recommends using Rolldown through Vite for most applications and points library authors to tsdown. Module types are experimental, and the JavaScript build() API may change in patch releases. The troubleshooting guide says Windows file-system access can slow builds, particularly when transforms run without plugins. An online REPL is linked, along with GitHub, Discord, and contribution resources. VoidZero Inc. holds the copyrights, funds development, and directs the project; it states Rolldown remains open source and MIT-licensed.

TypeScript Playground is a free browser environment for writing, running, sharing, and safely experimenting with TypeScript and JavaScript. It accepts .ts, .tsx, .js, .jsx, and .d.ts files. Run converts code to JavaScript, executes it in the current browser session, and shows console output in Logs; the browser session can also support DOM API experiments. The editor centers on one text document and is described as a teaching tool that needs no setup. Users can select supported TypeScript builds, including beta, nightly, pull request, and older builds. The TS Config panel exposes a focused compiler-option set, while twoslash annotations can configure options beyond it. URLs can preserve code, compiler flags, and settings for sharing. Export can create Markdown, open TypeScript AST Viewer, or export a project to CodeSandbox or StackBlitz. Plugins are supported, including Presentation Mode, Clippy, TSQuery, Collaborate, and Transformer. The mobile layout uses a single pane and does not show transpiled JavaScript beside source.