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Bun

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### [Read the docs →](https://bun.sh/docs) ## What is Bun? > **Bun is under active development.** Use it to speed up your development workflows or run simpler production code in resource-constrained environments like serverless functions. We're working on more complete Node.js compatibility and integration with existing frameworks. Join the [Discord](https://bun.sh/discord) and watch the [GitHub repository](https://github.com/oven-sh/bun) to keep tabs on future releases. 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. ```bash 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. ```bash bun test # run tests bun run start # run the `start` script in `package.json` bun install # install a package bunx cowsay 'Hello, world!' # execute a package ``` ## Install Bun supports Linux (x64 & arm64), macOS (x64 & Apple Silicon) and Windows (x64). > **Linux users** — Kernel version 5.6 or higher is strongly recommended, but the minimum is 5.1. ```sh # with install script (recommended) curl -fsSL https://bun.sh/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: ```sh bun upgrade ``` Bun automatically releases a canary build on every commit to `main`. To upgrade to the latest canary build, run: ```sh bun upgrade --canary ``` [View canary build](https://github.com/oven-sh/bun/releases/tag/canary) ## Quick links - Intro - [What is Bun?](https://bun.sh/docs/index) - [Installation](https://bun.sh/docs/installation) - [Quickstart](https://bun.sh/docs/quickstart) - [TypeScript](https://bun.sh/docs/typescript) - Templating - [`bun init`](https://bun.sh/docs/cli/init) - [`bun create`](https://bun.sh/docs/cli/bun-create) - Runtime - [`bun run`](https://bun.sh/docs/cli/run) - [File types](https://bun.sh/docs/runtime/loaders) - [TypeScript](https://bun.sh/docs/runtime/typescript) - [JSX](https://bun.sh/docs/runtime/jsx) - [Environment variables](https://bun.sh/docs/runtime/env) - [Bun APIs](https://bun.sh/docs/runtime/bun-apis) - [Web APIs](https://bun.sh/docs/runtime/web-apis) - [Node.js compatibility](https://bun.sh/docs/runtime/nodejs-apis) - [Single-file executable](https://bun.sh/docs/bundler/executables) - [Plugins](https://bun.sh/docs/runtime/plugins) - [Watch mode](https://bun.sh/docs/runtime/hot) - [Module resolution](https://bun.sh/docs/runtime/modules) - [Auto-install](https://bun.sh/docs/runtime/autoimport) - [bunfig.toml](https://bun.sh/docs/runtime/bunfig) - [Debugger](https://bun.sh/docs/runtime/debugger) - [Framework API](https://bun.sh/docs/runtime/framework) - Package manager - [`bun install`](https://bun.sh/docs/cli/install) - [`bun add`](https://bun.sh/docs/cli/add) - [`bun remove`](https://bun.sh/docs/cli/remove) - [`bun update`](https://bun.sh/docs/cli/update) - [`bun link`](https://bun.sh/docs/cli/link) - [`bun pm`](https://bun.sh/docs/cli/pm) - [Global cache](https://bun.sh/docs/install/cache) - [Workspaces](https://bun.sh/docs/install/workspaces) - [Lifecycle scripts](https://bun.sh/docs/install/lifecycle) - [Filter](https://bun.sh/docs/cli/filter) - [Lockfile](https://bun.sh/docs/install/lockfile) - [Scopes and registries](https://bun.sh/docs/install/registries) - [Overrides and resolutions](https://bun.sh/docs/install/overrides) - Bundler - [`Bun.build`](https://bun.sh/docs/bundler) - [Loaders](https://bun.sh/docs/bundler/loaders) - [Plugins](https://bun.sh/docs/bundler/plugins) - [Macros](https://bun.sh/docs/bundler/macros) - [vs esbuild](https://bun.sh/docs/bundler/vs-esbuild) - Test runner - [`bun test`](https://bun.sh/docs/cli/test) - [Writing tests](https://bun.sh/docs/test/writing) - [Watch mode](https://bun.sh/docs/test/hot) - [Lifecycle hooks](https://bun.sh/docs/test/lifecycle) - [Mocks](https://bun.sh/docs/test/mocks) - [Snapshots](https://bun.sh/docs/test/snapshots) - [Dates and times](https://bun.sh/docs/test/time) - [DOM testing](https://bun.sh/docs/test/dom) - [Code coverage](https://bun.sh/docs/test/coverage) - Package runner - [`bunx`](https://bun.sh/docs/cli/bunx) - API - [HTTP server](https://bun.sh/docs/api/http) - [WebSockets](https://bun.sh/docs/api/websockets) - [Workers](https://bun.sh/docs/api/workers) - [Binary data](https://bun.sh/docs/api/binary-data) - [Streams](https://bun.sh/docs/api/streams) - [File I/O](https://bun.sh/docs/api/file-io) - [import.meta](https://bun.sh/docs/api/import-meta) - [SQLite](https://bun.sh/docs/api/sqlite) - [FileSystemRouter](https://bun.sh/docs/api/file-system-router) - [TCP sockets](https://bun.sh/docs/api/tcp) - [UDP sockets](https://bun.sh/docs/api/udp) - [Globals](https://bun.sh/docs/api/globals) - [$ Shell](https://bun.sh/docs/runtime/shell) - [Child processes](https://bun.sh/docs/api/spawn) - [Transpiler](https://bun.sh/docs/api/transpiler) - [Hashing](https://bun.sh/docs/api/hashing) - [Console](https://bun.sh/docs/api/console) - [FFI](https://bun.sh/docs/api/ffi) - [HTMLRewriter](https://bun.sh/docs/api/html-rewriter) - [Testing](https://bun.sh/docs/api/test) - [Utils](https://bun.sh/docs/api/utils) - [Node-API](https://bun.sh/docs/api/node-api) - [Glob](https://bun.sh/docs/api/glob) - [Semver](https://bun.sh/docs/api/semver) - Project - [Roadmap](https://bun.sh/docs/project/roadmap) - [Benchmarking](https://bun.sh/docs/project/benchmarking) - [Contributing](https://bun.sh/docs/project/contributing) - [Building Windows](https://bun.sh/docs/project/building-windows) - [License](https://bun.sh/docs/project/licensing) ## Guides - Binary - [Convert an ArrayBuffer to an array of numbers](https://bun.sh/docs/guides/arraybuffer-to-array) - [Convert an ArrayBuffer to a Blob](https://bun.sh/docs/guides/arraybuffer-to-blob) - [Convert an ArrayBuffer to a Buffer](https://bun.sh/docs/guides/arraybuffer-to-buffer) - [Convert an ArrayBuffer to a string](https://bun.sh/docs/guides/arraybuffer-to-string) - [Convert an ArrayBuffer to a Uint8Array](https://bun.sh/docs/guides/arraybuffer-to-typedarray) - [Convert a Blob to an ArrayBuffer](https://bun.sh/docs/guides/blob-to-arraybuffer) - [Convert a Blob to a DataView](https://bun.sh/docs/guides/blob-to-dataview) - [Convert a Blob to a ReadableStream](https://bun.sh/docs/guides/blob-to-stream) - [Convert a Blob to a string](https://bun.sh/docs/guides/blob-to-string) - [Convert a Blob to a Uint8Array](https://bun.sh/docs/guides/blob-to-typedarray) - [Convert a Buffer to an ArrayBuffer](https://bun.sh/docs/guides/buffer-to-arraybuffer) - [Convert a Buffer to a blob](https://bun.sh/docs/guides/buffer-to-blob) - [Convert a Buffer to a ReadableStream](https://bun.sh/docs/guides/buffer-to-readablestream) - [Convert a Buffer to a string](https://bun.sh/docs/guides/buffer-to-string) - [Convert a Buffer to a Uint8Array](https://bun.sh/docs/guides/buffer-to-typedarray) - [Convert a DataView to a string](https://bun.sh/docs/guides/dataview-to-string) - [Convert a Uint8Array to an ArrayBuffer](https://bun.sh/docs/guides/typedarray-to-arraybuffer) - [Convert a Uint8Array to a Blob](https://bun.sh/docs/guides/typedarray-to-blob) - [Convert a Uint8Array to a Buffer](https://bun.sh/docs/guides/typedarray-to-buffer) - [Convert a Uint8Array to a DataView](https://bun.sh/docs/guides/typedarray-to-dataview) - [Convert a Uint8Array to a ReadableStream](https://bun.sh/docs/guides/typedarray-to-readablestream) - [Convert a Uint8Array to a string](https://bun.sh/docs/guides/typedarray-to-string) - Ecosystem - [Build an app with Astro and Bun](https://bun.sh/docs/guides/astro) - [Create a Discord bot](https://bun.sh/docs/guides/discordjs) - [Containerize a Bun application with Docker](https://bun.sh/docs/guides/docker) - [Use Drizzle ORM with Bun](https://bun.sh/docs/guides/drizzle) - [Use EdgeDB with Bun](https://bun.sh/docs/guides/edgedb) - [Build an HTTP server using Elysia and Bun](https://bun.sh/docs/guides/elysia) - [Build an HTTP server using Express and Bun](https://bun.sh/docs/guides/express) - [Build an HTTP server using Hono and Bun](https://bun.sh/docs/guides/hono) - [Read and write data to MongoDB using Mongoose and Bun](https://bun.sh/docs/guides/mongoose) - [Use Neon's Serverless Postgres with Bun](https://bun.sh/docs/guides/neon-serverless-postgres) - [Build an app with Next.js and Bun](https://bun.sh/docs/guides/nextjs) - [Build an app with Nuxt and Bun](https://bun.sh/docs/guides/nuxt) - [Run Bun as a daemon with PM2](https://bun.sh/docs/guides/pm2) - [Use Prisma with Bun](https://bun.sh/docs/guides/prisma) - [Build an app with Qwik and Bun](https://bun.sh/docs/guides/qwik) - [Use React and JSX](https://bun.sh/docs/guides/react) - [Build an app with Remix and Bun](https://bun.sh/docs/guides/remix) - [Build an app with SolidStart and Bun](https://bun.sh/docs/guides/solidstart) - [Server-side render (SSR) a React component](https://bun.sh/docs/guides/ssr-react) - [Build an HTTP server using StricJS and Bun](https://bun.sh/docs/guides/stric) - [Build an app with SvelteKit and Bun](https://bun.sh/docs/guides/sveltekit) - [Run Bun as a daemon with systemd](https://bun.sh/docs/guides/systemd) - [Build a frontend using Vite and Bun](https://bun.sh/docs/guides/vite) - HTTP - [fetch with unix domain sockets in Bun](https://bun.sh/docs/guides/fetch-unix) - [Send an HTTP request using fetch](https://bun.sh/docs/guides/fetch) - [Upload files via HTTP using FormData](https://bun.sh/docs/guides/file-uploads) - [Hot reload an HTTP server](https://bun.sh/docs/guides/hot) - [Proxy HTTP requests using fetch()](https://bun.sh/docs/guides/proxy) - [Common HTTP server usage](https://bun.sh/docs/guides/server) - [Write a simple HTTP server](https://bun.sh/docs/guides/simple) - [Stream a file as an HTTP Response](https://bun.sh/docs/guides/stream-file) - [Streaming HTTP Server with Async Iterators](https://bun.sh/docs/guides/stream-iterator) - [Streaming HTTP Server with Node.js Streams](https://bun.sh/docs/guides/stream-node-streams-in-bun) - [Configure TLS on an HTTP server](https://bun.sh/docs/guides/tls) - Install - [Add a development dependency](https://bun.sh/docs/guides/add-dev) - [Add a Git dependency](https://bun.sh/docs/guides/add-git) - [Add an optional dependency](https://bun.sh/docs/guides/add-optional) - [Add a peer dependency](https://bun.sh/docs/guides/add-peer) - [Add a tarball dependency](https://bun.sh/docs/guides/add-tarball) - [Add a dependency](https://bun.sh/docs/guides/add) - [Using bun install with an Azure Artifacts npm registry](https://bun.sh/docs/guides/azure-artifacts) - [Install dependencies with Bun in GitHub Actions](https://bun.sh/docs/guides/cicd) - [Override the default npm registry for bun install](https://bun.sh/docs/guides/custom-registry) - [Configure git to diff Bun's lockb lockfile](https://bun.sh/docs/guides/git-diff-bun-lockfile) - [Using bun install with Artifactory](https://bun.sh/docs/guides/jfrog-artifactory) - [Install a package under a different name](https://bun.sh/docs/guides/npm-alias) - [Configure a private registry for an organization scope with bun install](https://bun.sh/docs/guides/registry-scope) - [Add a trusted dependency](https://bun.sh/docs/guides/trusted) - [Configuring a monorepo using workspaces](https://bun.sh/docs/guides/workspaces) - [Generate a human-readable lockfile](https://bun.sh/docs/guides/yarnlock) - Process - [Parse command-line arguments](https://bun.sh/docs/guides/argv) - [Listen for CTRL+C](https://bun.sh/docs/guides/ctrl-c) - [Spawn a child process and communicate using IPC](https://bun.sh/docs/guides/ipc) - [Get the process uptime in nanoseconds](https://bun.sh/docs/guides/nanoseconds) - [Listen to OS signals](https://bun.sh/docs/guides/os-signals) - [Read stderr from a child process](https://bun.sh/docs/guides/spawn-stderr) - [Read stdout from a child process](https://bun.sh/docs/guides/spawn-stdout) - [Spawn a child process](https://bun.sh/docs/guides/spawn) - [Read from stdin](https://bun.sh/docs/guides/stdin) - Read file - [Read a file to an ArrayBuffer](https://bun.sh/docs/guides/arraybuffer) - [Read a file to a Buffer](https://bun.sh/docs/guides/buffer) - [Check if a file exists](https://bun.sh/docs/guides/exists) - [Read a JSON file](https://bun.sh/docs/guides/json) - [Get the MIME type of a file](https://bun.sh/docs/guides/mime) - [Read a file as a ReadableStream](https://bun.sh/docs/guides/stream) - [Read a file as a string](https://bun.sh/docs/guides/string) - [Read a file to a Uint8Array](https://bun.sh/docs/guides/uint8array) - [Watch a directory for changes](https://bun.sh/docs/guides/watch) - Runtime - [Install and run Bun in GitHub Actions](https://bun.sh/docs/guides/cicd) - [Define and replace static globals & constants](https://bun.sh/docs/guides/define-constant) - [Import HTML file as text](https://bun.sh/docs/guides/import-html) - [Import a JSON file](https://bun.sh/docs/guides/import-json) - [Import a TOML file](https://bun.sh/docs/guides/import-toml) - [Read environment variables](https://bun.sh/docs/guides/read-env) - [Set environment variables](https://bun.sh/docs/guides/set-env) - [Run a Shell Command](https://bun.sh/docs/guides/shell) - [Set a time zone in Bun](https://bun.sh/docs/guides/timezone) - [Re-map import paths](https://bun.sh/docs/guides/tsconfig-paths) - [Install TypeScript declarations for Bun](https://bun.sh/docs/guides/typescript) - [Debugging Bun with the VS Code extension](https://bun.sh/docs/guides/vscode-debugger) - [Debugging Bun with the web debugger](https://bun.sh/docs/guides/web-debugger) - Streams - [Convert a Node.js Readable to an ArrayBuffer](https://bun.sh/docs/guides/node-readable-to-arraybuffer) - [Convert a Node.js Readable to a Blob](https://bun.sh/docs/guides/node-readable-to-blob) - [Convert a Node.js Readable to JSON](https://bun.sh/docs/guides/node-readable-to-json) - [Convert a Node.js Readable to a string](https://bun.sh/docs/guides/node-readable-to-string) - [Convert a ReadableStream to an array of chunks](https://bun.sh/docs/guides/to-array) - [Convert a ReadableStream to an ArrayBuffer](https://bun.sh/docs/guides/to-arraybuffer) - [Convert a ReadableStream to a Blob](https://bun.sh/docs/guides/to-blob) - [Convert a ReadableStream to a Buffer](https://bun.sh/docs/guides/to-buffer) - [Convert a ReadableStream to JSON](https://bun.sh/docs/guides/to-json) - [Convert a ReadableStream to a string](https://bun.sh/docs/guides/to-string) - [Convert a ReadableStream to a Uint8Array](https://bun.sh/docs/guides/to-typedarray) - Test - [Bail early with the Bun test runner](https://bun.sh/docs/guides/bail) - [Set a code coverage threshold with the Bun test runner](https://bun.sh/docs/guides/coverage-threshold) - [Generate code coverage reports with the Bun test runner](https://bun.sh/docs/guides/coverage) - [Write browser DOM tests with Bun and happy-dom](https://bun.sh/docs/guides/happy-dom) - [Migrate from Jest to Bun's test runner](https://bun.sh/docs/guides/migrate-from-jest) - [Set the system time in Bun's test runner](https://bun.sh/docs/guides/mock-clock) - [Mock functions in `bun test`](https://bun.sh/docs/guides/mock-functions) - [Re-run tests multiple times with the Bun test runner](https://bun.sh/docs/guides/rerun-each) - [Run your tests with the Bun test runner](https://bun.sh/docs/guides/run-tests) - [Skip tests with the Bun test runner](https://bun.sh/docs/guides/skip-tests) - [Use snapshot testing in `bun test`](https://bun.sh/docs/guides/snapshot) - [Spy on methods in `bun test`](https://bun.sh/docs/guides/spy-on) - [Set a per-test timeout with the Bun test runner](https://bun.sh/docs/guides/timeout) - [Mark a test as a "todo" with the Bun test runner](https://bun.sh/docs/guides/todo-tests) - [Update snapshots in `bun test`](https://bun.sh/docs/guides/update-snapshots) - [Run tests in watch mode with Bun](https://bun.sh/docs/guides/watch-mode) - Util - [Encode and decode base64 strings](https://bun.sh/docs/guides/base64) - [Check if two objects are deeply equal](https://bun.sh/docs/guides/deep-equals) - [Compress and decompress data with DEFLATE](https://bun.sh/docs/guides/deflate) - [Detect when code is executed with Bun](https://bun.sh/docs/guides/detect-bun) - [Check if the current file is the entrypoint](https://bun.sh/docs/guides/entrypoint) - [Escape an HTML string](https://bun.sh/docs/guides/escape-html) - [Convert a file URL to an absolute path](https://bun.sh/docs/guides/file-url-to-path) - [Compress and decompress data with gzip](https://bun.sh/docs/guides/gzip) - [Hash a password](https://bun.sh/docs/guides/hash-a-password) - [Get the directory of the current file](https://bun.sh/docs/guides/import-meta-dir) - [Get the file name of the current file](https://bun.sh/docs/guides/import-meta-file) - [Get the absolute path of the current file](https://bun.sh/docs/guides/import-meta-path) - [Get the absolute path to the current entrypoint](https://bun.sh/docs/guides/main) - [Convert an absolute path to a file URL](https://bun.sh/docs/guides/path-to-file-url) - [Sleep for a fixed number of milliseconds](https://bun.sh/docs/guides/sleep) - [Get the current Bun version](https://bun.sh/docs/guides/version) - [Get the path to an executable bin file](https://bun.sh/docs/guides/which-path-to-executable-bin) - WebSocket - [Enable compression for WebSocket messages](https://bun.sh/docs/guides/compression) - [Set per-socket contextual data on a WebSocket](https://bun.sh/docs/guides/context) - [Build a publish-subscribe WebSocket server](https://bun.sh/docs/guides/pubsub) - [Build a simple WebSocket server](https://bun.sh/docs/guides/simple) - Write file - [Append content to a file](https://bun.sh/docs/guides/append) - [Write a string to a file](https://bun.sh/docs/guides/basic) - [Write a Blob to a file](https://bun.sh/docs/guides/blob) - [Write a file to stdout](https://bun.sh/docs/guides/cat) - [Copy a file to another location](https://bun.sh/docs/guides/file-cp) - [Write a file incrementally](https://bun.sh/docs/guides/filesink) - [Write a Response to a file](https://bun.sh/docs/guides/response) - [Write to stdout](https://bun.sh/docs/guides/stdout) - [Write a ReadableStream to a file](https://bun.sh/docs/guides/stream) - [Delete a file](https://bun.sh/docs/guides/unlink) ## Contributing Refer to the [Project > Contributing](https://bun.sh/docs/project/contributing) guide to start contributing to Bun. ## License Refer to the [Project > License](https://bun.sh/docs/project/licensing) page for information about Bun's licensing.