Command Line Interface

For proper usage and easier distribution of this configuration, webpack can be configured with webpack.config.js. Any parameters sent to the CLI will map to a corresponding parameter in the configuration file.

Read the installation guide if you don't already have webpack and CLI installed.


webpack-cli offers a variety of commands to make working with webpack easier. By default webpack ships with

buildbuild|bundle|b [entries...] [options]Run webpack (default command, can be omitted).
configtestconfigtest|t [config-path]Validate a webpack configuration.
helphelp|h [command] [option]Display help for commands and options.
infoinfo|i [options]Outputs information about your system.
initinit|create|c|new|n [generation-path] [options]Initialize a new webpack project.
loaderloader|l [output-path] [options]Scaffold a loader.
pluginplugin|p [output-path] [options]Scaffold a plugin.
serveserve|server|s [options]Run the webpack-dev-server.
versionversion|v [commands...]Output the version number of webpack, webpack-cli and webpack-dev-server.
watchwatch|w [entries...] [options]Run webpack and watch for files changes.


Run webpack (default command, can be omitted).

npx webpack build [options]


npx webpack build --config ./webpack.config.js --stats verbose


Used to initialize a new webpack project.

npx webpack init [generation-path] [options]


npx webpack init ./my-app --force --template=default

Generation Path

Location of where to generate the configuration. Defaults to process.cwd().


-t, --template

string = 'default'

Name of template to generate.

-f, --force


To generate a project without questions. When enabled, the default answer for each question will be used.


Scaffold a loader.

npx webpack loader [output-path] [options]


npx webpack loader ./my-loader --template=default

Output Path

Path to the output directory, e.g. ./loader-name.


-t, --template

string = 'default'

Type of template.


Scaffold a plugin.

npx webpack plugin [output-path] [options]


npx webpack plugin ./my-plugin --template=default

Output Path

Path to the output directory, e.g. ./plugin-name.


-t, --template

string = 'default'

Type of template.


Outputs information about your system.

npx webpack info [options]


npx webpack info --output json --addition-package postcss

Options for info

-a, --additional-package


Adds additional packages to the output.


npx webpack info --additional-package postcss

-o, --output

string : 'json' | 'markdown'

To get the output in a specified format.


npx webpack info --output markdown


Validate a webpack configuration.

npx webpack configtest [config-path]


npx webpack configtest ./webpack.config.js

Config Path

Path to your webpack configuration file. Defaults to ./webpack.config.js.


Run the webpack dev server.

npx webpack serve [options]


npx webpack serve --static --open


Run webpack and watch for files changes.

npx webpack watch [options]


npx webpack watch --mode development


By default webpack ships with the following flags:

Flag / AliasTypeDescription
--entrystring[]The entry point(s) of your application e.g. ./src/main.js
--config, -cstring[]Provide path to a webpack configuration file e.g. ./webpack.config.js
--config-namestring[]Name of the configuration to use
--namestringName of the configuration. Used when loading multiple configurations
--colorbooleanEnable colors on console
--merge, -mbooleanMerge two or more configurations using webpack-merge
--envstring[]Environment passed to the configuration when it is a function
--define-process-env-node-envstringSet process.env.NODE_ENV to the specified value
--progressboolean, stringPrint compilation progress during build
--helpbooleanOutputs list of supported flags and commands
--output-path, -ostringOutput location of the file generated by webpack e.g. ./dist
--target, -tstring[]Sets the build target
--watch, -wbooleanWatch for file changes
--watch-options-stdinbooleanStop watching when stdin stream has ended
--devtool, -dstringControls if and how source maps are generated.
--json, -jboolean, stringPrints result as JSON or store it in a file
--modestringDefines the mode to pass to webpack
--version, -vbooleanGet current version
--statsboolean, stringIt instructs webpack on how to treat the stats
--disable-interpretbooleanDisable interpret for loading the config file.
--fail-on-warningsbooleanStop webpack-cli process with non-zero exit code on warnings from webpack
--analyzebooleanIt invokes webpack-bundle-analyzer plugin to get bundle information
--extends, -estring[]Extend an existing configuration

Negated Flags

--no-colorDisables any color on the console
--no-hotDisables hot reloading if you have it enabled via your config
--no-statsDisables any compilation stats emitted by webpack
--no-watchDo not watch for file changes
--no-devtoolDo not generate source maps
--no-watch-options-stdinDo not stop watching when stdin stream has ended

Core Flags

Starting CLI v4 and webpack v5, CLI imports the entire configuration schema from webpack core to allow tuning almost every configuration option from the command line.

Here's the list of all the core flags supported by webpack v5 with CLI v4 - link

For example if you want to enable performance hints in your project you'd use this option in configuration, with core flags you can do -

npx webpack --performance-hints warning


With configuration file

npx webpack [--config webpack.config.js]

See configuration for the options in the configuration file.

Without configuration file

npx webpack --entry <entry> --output-path <output-path>


npx webpack --entry ./first.js --entry ./second.js --output-path /build


A filename or a set of named filenames which act as the entry point to build your project. You can pass multiple entries (every entry is loaded on startup). Following are the multiple ways of specifying entry file(s) via CLI -

npx webpack --entry-reset ./first-entry.js
npx webpack --entry-reset --entry ./first-entry.js
npx webpack --entry-reset ./first-entry.js ./other-entry.js
npx webpack --entry-reset --entry ./first-entry.js ./other-entry.js


A path for the bundled file to be saved in. It will be mapped to the configuration options output.path.


If your project structure is as follows -

├── dist
├── index.html
└── src
    ├── index.js
    ├── index2.js
    └── others.js
npx webpack ./src/index.js --output-path dist

This will bundle your source code with entry as index.js, and the output bundle file will have a path of dist.

asset main.js 142 bytes [compared for emit] [minimized] (name: main)
./src/index.js 30 bytes [built] [code generated]
./src/others.js 1 bytes [built] [code generated]
webpack 5.1.0 compiled successfully in 187 ms
npx webpack ./src/index.js ./src/others2.js --output-path dist/

This will form the bundle with both the files as separate entry points.

asset main.js 142 bytes [compared for emit] [minimized] (name: main)
./src/index.js 30 bytes [built] [code generated]
./src/others2.js 1 bytes [built] [code generated]
./src/others.js 1 bytes [built] [code generated]
webpack 5.1.0 compiled successfully in 198 ms

Default Configurations

CLI will look for some default configurations in the path of your project, here are the config files picked up by CLI.

This is the lookup priority in increasing order

example - config file lookup will be in order of .webpack/webpackfile > .webpack/webpack.config.js > webpack.config.js


Common Options


List basic commands and flags available on the cli

Both webpack help [command] [option] and webpack [command] --help are valid to get help:

npx webpack --help

# or

npx webpack help

List all supported commands and flags by cli

npx webpack --help=verbose

See help for a specific command or option

npx webpack help --mode


Show version of installed packages and sub-packages

To inspect the version of webpack and webpack-cli you are using, run the command:

npx webpack --version

# or

npx webpack version

This will output the following result:

webpack 5.31.2
webpack-cli 4.6.0

It will output the version of webpack-dev-server as well if you have it installed:

webpack 5.31.2
webpack-cli 4.6.0
webpack-dev-server 3.11.2

To inspect the version of any webpack-cli sub-package (like @webpack-cli/info), run command similar to the following:

npx webpack info --version

This will output the following result:

@webpack-cli/info 1.2.3
webpack 5.31.2
webpack-cli 4.6.0
webpack-dev-server 3.11.2


Build source using a configuration file

Specify a different configuration file other than webpack.config.js, which is one of the defaults.

npx webpack --config example.config.js


In case your configuration file exports multiple configurations, you can use --config-name to specify which configuration to run.

Consider the following webpack.config.js:

module.exports = [
    output: {
      filename: './dist-first.js',
    name: 'first',
    entry: './src/first.js',
    mode: 'development',
    output: {
      filename: './dist-second.js',
    name: 'second',
    entry: './src/second.js',
    mode: 'development',
    output: {
      filename: './dist-third.js',
    name: 'third',
    entry: './src/third.js',
    mode: 'none',
    stats: 'verbose',

To run only the second configuration:

npx webpack --config-name second

You can also pass multiple values:

npx webpack --config-name first --config-name second


You can merge two or more different webpack configurations with the help of --merge:

npx webpack --config ./first.js --config ./second.js --merge


webpack-cli v5.1.0+

You can extend existing webpack configurations with the help of --extends:

npx webpack --extends ./base.webpack.config.js


Print result of webpack as JSON

npx webpack --json

If you want to store stats as json instead of printing it, you can use -

npx webpack --json stats.json

In every other case, webpack prints out a set of stats showing bundle, chunk and timing details. Using this option, the output can be a JSON object. This response is accepted by webpack's analyse tool, or chrisbateman's webpack-visualizer, or th0r's webpack-bundle-analyzer. The analyse tool will take in the JSON and provide all the details of the build in graphical form.

Environment Options

When the webpack configuration exports a function, an "environment" may be passed to it.


npx webpack --env production    # env.production = true

The --env argument accepts multiple values:

InvocationResulting environment
npx webpack --env prod{ prod: true }
npx webpack --env prod --env min{ prod: true, min: true }
npx webpack --env platform=app --env production{ platform: "app", production: true }
npx webpack --env foo=bar=app{ foo: "bar=app"}
npx webpack --env app.platform="staging" --env"test"{ app: { platform: "staging", name: "test" }

In addition to the customized env showed above, there are some built-in ones under env to be used inside your webpack configuration:

Environment VariableDescription
WEBPACK_SERVEtrue if serve|server|s is being used.
WEBPACK_BUILDtrue if build|bundle|b is being used.
WEBPACK_WATCHtrue if --watch|watch|w is being used.

Note that you can not access those built-in environment variables inside the bundled code.

module.exports = (env, argv) => {
  return {
    mode: env.WEBPACK_SERVE ? 'development' : 'production',


You can use --node-env option to set process.env.NODE_ENV, which is available to both user code and webpack configuration:

npx webpack --node-env production   # process.env.NODE_ENV = 'production'


For webpack-cli v5+.

An alias for --node-env to set process.env.NODE_ENV:

npx webpack --define-process-env-node-env production   # process.env.NODE_ENV = 'production'

Configuration Options

ParameterExplanationInput typeDefault
--configPath to the configuration filestring[]Default Configs
--config-nameName of the configuration to usestring[]-
--envEnvironment passed to the configuration, when it is a functionstring[]-

Analyzing Bundle

You can also use webpack-bundle-analyzer to analyze your output bundles emitted by webpack. You can use --analyze flag to invoke it via CLI.

npx webpack --analyze


To check the progress of any webpack compilation you can use the --progress flag.

npx webpack --progress

To collect profile data for progress steps you can pass profile as value to --progress flag.

npx webpack --progress=profile

Pass CLI arguments to Node.js

To pass arguments directly to Node.js process, you can use the NODE_OPTIONS option.

For example, to increase the memory limit of Node.js process to 4 GB

NODE_OPTIONS="--max-old-space-size=4096" webpack

Also, you can pass multiple options to Node.js process

NODE_OPTIONS="--max-old-space-size=4096 -r /path/to/preload/file.js" webpack

Exit codes and their meanings

Exit CodeDescription
1Errors from webpack
2Configuration/options problem or an internal error

CLI Environment Variables

Environment VariableDescription
WEBPACK_CLI_SKIP_IMPORT_LOCALwhen true it will skip using the local instance of webpack-cli.
WEBPACK_CLI_FORCE_LOAD_ESM_CONFIGwhen true it will force load the ESM config.
WEBPACK_PACKAGEUse a custom webpack version in CLI.
WEBPACK_DEV_SERVER_PACKAGEUse a custom webpack-dev-server version in CLI.
WEBPACK_CLI_HELP_WIDTHUse a custom width for help output.
WEBPACK_CLI_FORCE_LOAD_ESM_CONFIG=true npx webpack --config ./webpack.config.esm


Use a custom webpack version in CLI. Considering the following content in your package.json:

  "webpack": "^4.0.0",
  "webpack-5": "npm:webpack@^5.32.0",
  "webpack-cli": "^4.5.0"

To use webpack v4.0.0:

npx webpack

To use webpack v5.32.0:

WEBPACK_PACKAGE=webpack-5 npx webpack


TypeError [ERR_UNKNOWN_FILE_EXTENSION]: Unknown file extension ".ts" for ./webpack.config.ts

You might encounter this error in the case of using native ESM in TypeScript (i.e. type: "module" in package.json).

webpack-cli supports configuration in both CommonJS and ESM format, at first it tries to load a configuration using require(), once it fails with an error code of 'ERR_REQUIRE_ESM' (a special code for this case) it would try to load the configuration using import(). However, the import() method won't work with ts-node without loader hooks enabled (described at TypeStrong/ts-node#1007).

To fix the error above use the following command:

NODE_OPTIONS="--loader ts-node/esm" npx webpack --entry ./src/index.js --mode production

For more information, see our documentation on writing a webpack configuration in TypeScript.

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