Bun
by oven-sh
Bun: Lightning-Fast All-in-One JavaScript Toolkit
A blazingly fast JavaScript runtime built with Zig that combines bundling, testing, and package management into a single, optimized tool.
- 86,536+ GitHub stars
- Built with Zig
- Native TypeScript and JSX execution without transpilation configuration
- Other license
About This Project
Bun revolutionizes JavaScript development by consolidating your entire toolchain into one high-performance executable. Built from the ground up using Zig and powered by JavaScriptCore, it delivers dramatically faster startup times and execution speeds compared to traditional Node.js environments.
This comprehensive toolkit eliminates the need to juggle multiple tools like Webpack, Jest, and npm. Bun natively executes TypeScript and JSX without configuration, bundles your code for production, runs your test suites, and manages dependencies—all with a unified API and consistent performance characteristics.
The project stands out through its drop-in compatibility with Node.js APIs while offering significant speed improvements. Developers can migrate existing projects incrementally, adopting Bun's bundler or test runner without rewriting application code. Its built-in transpiler handles modern JavaScript, TypeScript, and React syntax out of the box.
With a focus on developer experience, Bun reduces configuration overhead and build times, letting teams ship faster. Whether you're building web applications, CLI tools, or server-side APIs, Bun provides a streamlined workflow that respects the JavaScript ecosystem while pushing performance boundaries.
Key Features
- Native TypeScript and JSX execution without transpilation configuration
- Built-in bundler, test runner, and package manager in a single binary
- JavaScriptCore engine delivering 3-4x faster startup than Node.js
- Drop-in Node.js compatibility for seamless migration of existing projects
- Zero-configuration hot reloading and watch mode for development
- Native Web APIs support including fetch, WebSocket, and ReadableStream
- Fast package installation with automatic lockfile management
How You Can Use It
Replacing Node.js in production environments for faster API response times and reduced cold starts
Building and bundling React or TypeScript applications without complex Webpack configurations
Running test suites with built-in test runner that's significantly faster than Jest or Mocha
Managing npm packages with faster installation and resolution than traditional package managers
Developing full-stack JavaScript applications with a single, consistent runtime environment
Creating command-line tools that start instantly and execute efficiently
Who Is This For?
JavaScript and TypeScript developers seeking performance improvements, full-stack engineers tired of tooling complexity, and teams looking to consolidate their development infrastructure