Bun

<p align="center"> <a href="https://bun.com"><img src="https://github.com/user-attachments/assets/50282090-adfd-4ddb-9e27-c30753c6b161" alt="Logo" height=170></a> </p> <h1 align="center">Bun</h1> <p align="center"> <a href="https://bun.com/discord" target="_blank"><img height=20 src="https://img.shields.io/discord/876711213126520882" /></a> <img src="https://img.shields.io/github/stars/oven-sh/bun" alt="stars"> <a href="https://twitter.com/jarredsumner/status/1542824445810642946"><img src="https://img.shields.io/static/v1?label=speed&message=fast&color=success" alt="Bun speed" /></a> </p> <div align="center"> <a href="https://bun.com/docs">Documentation</a> <span>&nbsp;&nbsp;•&nbsp;&nbsp;</span> <a href="https://discord.com/invite/CXdq2DP29u">Discord</a> <span>&nbsp;&nbsp;•&nbsp;&nbsp;</span> <a href="https://github.com/oven-sh/bun/issues/new">Issues</a> <span>&nbsp;&nbsp;•&nbsp;&nbsp;</span> <a href="https://github.com/oven-sh/bun/issues/159">Roadmap</a> <br /> </div>

Read the docs →

What is Bun?

Bun is an all-in-one toolkit for JavaScript and TypeScript apps. It ships as a single executable called bun.

At its core is the Bun runtime, a fast JavaScript runtime designed as a drop-in replacement for Node.js. It's written in Zig and powered by JavaScriptCore under the hood, dramatically reducing startup times and memory usage.

bun run index.tsx             # TS and JSX supported out-of-the-box

The bun command-line tool also implements a test runner, script runner, and Node.js-compatible package manager. Instead of 1,000 node_modules for development, you only need bun. Bun's built-in tools are significantly faster than existing options and usable in existing Node.js projects with little to no changes.

bun test                      # run tests
bun run start                 # run the `start` script in `package.json`
bun install <pkg>             # install a package
bunx cowsay 'Hello, world!'   # execute a package

Install

Bun supports Linux (x64 & arm64), macOS (x64 & Apple Silicon), and Windows (x64 & arm64).

Linux users — Kernel version 5.6 or higher is strongly recommended, but the minimum is 5.1.

x64 users — if you see "illegal instruction" or similar errors, check our CPU requirements

# with install script (recommended)
curl -fsSL https://bun.com/install | bash

# on windows
powershell -c "irm bun.sh/install.ps1 | iex"

# with npm
npm install -g bun

# with Homebrew
brew tap oven-sh/bun
brew install bun

# with Docker
docker pull oven/bun
docker run --rm --init --ulimit memlock=-1:-1 oven/bun

Upgrade

To upgrade to the latest version of Bun, run:

bun upgrade

Bun automatically releases a canary build on every commit to main. To upgrade to the latest canary build, run:

bun upgrade --canary

View canary build

Quick links

• Intro

  • What is Bun?
  • Installation
  • Quickstart
  • TypeScript

• Templating

  • bun init
  • bun create

• CLI

  • bun upgrade

• Runtime

  • bun run
  • File types (Loaders)
  • TypeScript
  • JSX
  • Environment variables
  • Bun APIs
  • Web APIs
  • Node.js compatibility
  • Single-file executable
  • Plugins
  • Watch mode / Hot Reloading
  • Module resolution
  • Auto-install
  • bunfig.toml
  • Debugger
  • $ Shell

• Package manager

  • bun install
  • bun add
  • bun remove
  • bun update
  • bun link
  • bun unlink
  • bun pm
  • bun outdated
  • bun publish
  • bun patch
  • bun patch-commit
  • Global cache
  • Workspaces
  • Lifecycle scripts
  • Filter
  • Lockfile
  • Scopes and registries
  • Overrides and resolutions
  • .npmrc

• Bundler

  • Bun.build
  • Loaders
  • Plugins
  • Macros
  • vs esbuild
  • Single-file executable
  • CSS
  • HTML
  • Hot Module Replacement (HMR)
  • Full-stack with HTML imports

• Test runner

  • bun test
  • Writing tests
  • Watch mode
  • Lifecycle hooks
  • Mocks
  • Snapshots
  • Dates and times
  • DOM testing
  • Code coverage
  • Configuration
  • Discovery
  • Reporters
  • Runtime Behavior

• Package runner

  • bunx

• API

  • HTTP server (Bun.serve)
  • WebSockets
  • Workers
  • Binary data
  • Streams
  • File I/O (Bun.file)
  • import.meta
  • SQLite (bun:sqlite)
  • PostgreSQL (Bun.sql)
  • Redis (Bun.redis)
  • S3 Client (Bun.s3)
  • FileSystemRouter
  • TCP sockets
  • UDP sockets
  • Globals
  • $ Shell
  • Child processes (spawn)
  • Transpiler (Bun.Transpiler)
  • Hashing
  • Colors (Bun.color)
  • Console
  • FFI (bun:ffi)
  • C Compiler (bun:ffi cc)
  • HTMLRewriter
  • Testing (bun:test)
  • Cookies (Bun.Cookie)
  • Utils
  • Node-API
  • Glob (Bun.Glob)
  • Semver (Bun.semver)
  • DNS
  • fetch API extensions

Guides

• Binary
  • Convert a Blob to a string
  • Convert a Buffer to a blob
  • Convert a Blob to a DataView
  • Convert a Buffer to a string
  • Convert a Blob to a ReadableStream
  • Convert a Blob to a Uint8Array
  • Convert a DataView to a string
  • Convert a Uint8Array to a Blob
  • Convert a Blob to an ArrayBuffer
  • Convert an ArrayBuffer to a Blob
  • Convert a Buffer to a Uint8Array
  • Convert a Uint8Array to a Buffer
  • Convert a Uint8Array to a string
  • Convert a Buffer to an ArrayBuffer
  • Convert an ArrayBuffer to a Buffer
  • [Convert an ArrayBuffer to a string](https://bun.com/g