Features
- Built-in bundler, test runner, and package manager
- Native TypeScript and JSX support without transpilation
- SQLite driver built into the runtime
- Web-standard APIs (fetch, WebSocket, streams)
Pros
- Dramatically faster than Node.js for many workloads
- Single tool replaces node, npm, webpack, jest
- Drop-in Node.js compatibility for most packages
Cons
- Younger ecosystem with less production battle-testing
- Some Node.js APIs not yet fully implemented
- Linux and macOS focused, Windows support still maturing
Overview
Bun is an all-in-one JavaScript runtime designed as a drop-in replacement for Node.js, built from scratch using Zig and JavaScriptCore (Safari’s engine) instead of V8. It ships with a built-in bundler, test runner, and package manager that are significantly faster than their Node.js equivalents.
Bun natively supports TypeScript and JSX without any configuration or build step. It also includes a built-in SQLite driver, making it easy to work with local databases. Its focus on speed and developer experience has made it one of the fastest-growing JavaScript tools.
When to Use
Choose Bun when startup speed and runtime performance are priorities, when you want a single tool for package management, bundling, testing, and execution, or when building new projects that can leverage its all-in-one approach without relying on niche Node.js-only APIs.
Getting Started
curl -fsSL https://bun.sh/install | bash
# Create a new project
bun init
bun run index.tsconst server = Bun.serve({
port: 3000,
fetch(req) {
return new Response("Hello from Bun!");
},
});