bun build CLI Usage

bun build <entry points>

General Configuration

--productionboolean

Set NODE_ENV=production and enable minification

--bytecodeboolean

Use a bytecode cache when compiling

--targetstring default: browser

Intended execution environment for the bundle. One of browser, bun, or node

--conditionsstring

Pass custom resolution conditions

--envstring default: disable

Inline environment variables into the bundle as process.env.${name}. To inline variables matching a prefix, use a glob like FOO_PUBLIC_*

Output & File Handling

--outdirstring default: dist

Output directory (used when building multiple entry points)

--outfilestring

Write output to a specific file

--sourcemapstring default: none

Generate source maps. One of linked, inline, external, or none

--bannerstring

Add a banner to the output (e.g. "use client" for React Server Components)

--footerstring

Add a footer to the output (e.g. // built with bun!)

--formatstring default: esm

Module format of the output bundle. One of esm, cjs, or iife

File Naming

--entry-namingstring default: [dir]/[name].[ext]

Customize entry point filenames

--chunk-namingstring default: [name]-[hash].[ext]

Customize chunk filenames

--asset-namingstring default: [name]-[hash].[ext]

Customize asset filenames

Bundling Options

--rootstring

Root directory used when bundling multiple entry points

--splittingboolean

Enable code splitting for shared modules

--public-pathstring

Prefix to be added to import paths in bundled code

--externalstring

Exclude modules from the bundle (supports wildcards). Alias: -e

--packagesstring default: bundle

How to treat dependencies: external or bundle

--no-bundleboolean

Transpile only — do not bundle

--css-chunkingboolean

Chunk CSS files together to reduce duplication (only when multiple entry points import CSS)

Minification & Optimization

--emit-dce-annotationsboolean default: true

Re-emit Dead Code Elimination annotations. Disabled when --minify-whitespace is used

--minifyboolean

Enable all minification options

--minify-syntaxboolean

Minify syntax and inline constants

--minify-whitespaceboolean

Minify whitespace

--minify-identifiersboolean

Minify variable and function identifiers

--keep-namesboolean

Preserve original function and class names when minifying

Development Features

--watchboolean

Rebuild automatically when files change

--no-clear-screenboolean

Don’t clear the terminal when rebuilding with --watch

--react-fast-refreshboolean

Enable React Fast Refresh transform (for development testing)

Standalone Executables

--compileboolean

Generate a standalone Bun executable containing the bundle. Implies --production

--compile-exec-argvstring

Prepend arguments to the standalone executable’s execArgv

Windows Executable Details

--windows-hide-consoleboolean

Prevent a console window from opening when running a compiled Windows executable

--windows-iconstring

Set an icon for the Windows executable

--windows-titlestring

Set the Windows executable product name

--windows-publisherstring

Set the Windows executable company name

--windows-versionstring

Set the Windows executable version (e.g. 1.2.3.4)

--windows-descriptionstring

Set the Windows executable description

--windows-copyrightstring

Set the Windows executable copyright notice

Experimental & App Building

--appboolean

(EXPERIMENTAL) Build a web app for production using Bun Bake

--server-componentsboolean

(EXPERIMENTAL) Enable React Server Components

--debug-dump-server-filesboolean

When --app is set, dump all server files to disk even for static builds

--debug-no-minifyboolean

When --app is set, disable all minification