esbuild

Bundle a JavaScript application and print to stdout

$ esbuild --bundle [path/to/file.js]

$ esbuild < [path/to/file.jsx] --bundle --outfile=[path/to/out.js]

$ esbuild --bundle --define:[process.env.NODE_ENV=\"production\"] --minify --sourcemap [path/to/file.js]

$ esbuild --bundle --minify --sourcemap --target=[chrome58,firefox57,safari11,edge16] [path/to/file.jsx]

$ esbuild --bundle --platform=[node] --target=[node12] [path/to/file.js]

$ esbuild --bundle app.js --loader:[.js=jsx] [path/to/file.js]

$ esbuild --bundle --serve=[port] --outfile=[index.js] [path/to/file.js]

$ esbuild --bundle --outdir=[path/to/output_directory] [path/to/file1 path/to/file2 ...]

esbuild [options] [--] [entry-points...]

--bundle
    Bundle input files together into a single output file (default: false)

--splitting
    Enable code splitting (requires --format=esm --platform=browser) (default: false)

--format=<format>
    Set output format: esm, cjs, iife, or umd (default: detect from outfile)

--platform=<platform>
    Target platform: browser, node, or neutral (default: browser)

--target=<target>
    Environment target such as es2020, chrome58, or node16 (default: browserslist)

--outfile=<file>
    Write single output file to disk

--outdir=<dir>
    Write multiple output files to directory

--out-extension:.<ext>=<ext>
    Force output extension, e.g. --out-extension:.js=.mjs

--entry-names=<tmpl>
    Template for entry point filenames, e.g. [dir]/[name]-[hash].js

--chunk-names=<tmpl>
    Template for code splitting chunk filenames

--asset-names=<tmpl>
    Template for non-JS asset filenames

--loader:<ext>=<loader>
    Loader for files: js, jsx, ts, tsx, css, file, copy, text, json, base64 (repeatable)

--external:<name>
    Exclude symbol from bundling (repeatable)

--global-name=<name>
    Global name for UMD/IIFE (repeatable)

--sourcemap
    Emit source map (inline, external, both) (default: false)

--minify
    Minify JS (syntax, whitespace, identifiers)

--metafile=<file>
    Emit build metadata JSON

--jsx=<hint>
    transform or preserve JSX (default: transform)

--jsx-factory=<ident>
    JSX factory function (default: React.createElement)

--define:<name>=<value>
    Replace expression with constant (repeatable)

--inject=<file>
    Inject globals from JS file (repeatable)

--banner:<type>=<text>
    Prepend banner to output (js, css) (repeatable)

--watch
    Watch files and rebuild on change

--serve=<host:port>
    Start dev server (default: localhost:8000)

--servedir=<dir>
    Serve static files from dir (default: .) (repeatable)

--log-level=<level>
    verbose, debug, info, warning, error, silent

--color=<bool>
    Force color in terminal output

--write
    Enable/disable writing to disk (default: true)

esbuild is an extremely fast bundler and minifier for JavaScript, TypeScript, and related assets. Written in Go, it achieves 10-100x speedups over JavaScript-based tools like webpack, Rollup, Terser, or Babel by using parallelism, low-level optimizations, and skipping unnecessary AST parsing.

Key features include bundling multiple modules, code splitting, tree shaking, minification, source map generation, transpilation (ES5-ES2022+), JSX transformation, CSS/JSON asset handling, and a built-in dev server. It supports ESM, CJS, IIFE, and UMD formats for browser, Node.js, or neutral platforms.

Usage spans web apps, Node.js servers, libraries, and CI builds. Install globally via npm: npm install -g esbuild, or use locally with npx. No runtime deps; single binary ~10MB. Ideal for large codebases where build time matters.

Limitations: fewer plugins than webpack; focused on core speed.

Not a standard Linux utility; requires separate installation. Lacks extensive plugin ecosystem compared to webpack. Binary size ~10MB but no Node.js runtime needed.

npm install esbuild --save-dev
Or download standalone binary from GitHub releases for Linux x64/arm64.

esbuild app.js --bundle --outfile=out.js
esbuild src/*.ts --bundle --outdir=dist --format=esm --platform=node --watch
esbuild --serve=localhost:8080 --servedir=public

Created by Evan Wallace (Segment.io/Grammarly) and open-sourced in September 2020 under MIT. Rapid adoption due to speed benchmarks; v0.8+ added TypeScript/JSX. Actively maintained with frequent releases.

npm(1), npx(1), node(1)