Command Line Interface

For proper usage and easy 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.

Usage with configuration file

webpack [--config webpack.config.js]

See configuration for the options in the configuration file.

Usage without configuration file

webpack <entry> [<entry>] -o <output>

<entry>

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). If you pass a pair in the form <name>=<request>, you can create an additional entry point. It will be mapped to the configuration option entry.

<output>

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

Example

If your project structure is as follows -

.
├── dist
├── index.html
└── src
    ├── index.js
    ├── index2.js
    └── others.js

webpack src/index.js -o dist/bundle.js

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

	| Asset     | Size    | Chunks      | Chunk Names |
	|-----------|---------|-------------|-------------|
	| bundle.js | 1.54 kB | 0 [emitted] | index       |
	[0] ./src/index.js 51 bytes {0} [built]
	[1] ./src/others.js 29 bytes {0} [built]

webpack ./src/index.js ./src.index2.js -o dist/bundle.js

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

	| Asset     | Size    | Chunks        | Chunk Names   |
	|-----------|---------|---------------|---------------|
	| bundle.js | 1.55 kB | 0,1 [emitted] | index, index2 |
	[0] ./src/index.js 51 bytes {0} [built]
	[0] ./src/index2.js 54 bytes {1} [built]
	[1] ./src/others.js 29 bytes {0} {1} [built]

Common Options

Note that Command Line Interface has a higher precedence for the arguments you use it with than your configuration file. For instance, if you pass --mode="production" to webpack CLI and your configuration file uses development, production will be used.

List all of the options available on the cli

webpack --help
webpack -h

Build source using a configuration file

Specifies a different configuration file to pick up. Use this if you want to specify something different from webpack.config.js, which is the default.

webpack --config example.config.js

Print result of webpack as a JSON

webpack --json
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.

webpack --env.production    # sets env.production == true
webpack --env.platform=web  # sets env.platform == "web"

The --env argument accepts various syntaxes:

Invocation	Resulting environment
Invocation Resulting environment webpack --env prod "prod"	"prod"
Invocation Resulting environment webpack --env.prod { prod: true }	{ prod: true }
Invocation Resulting environment webpack --env.prod=1 { prod: 1 }	{ prod: 1 }
Invocation Resulting environment webpack --env.prod=foo { prod: "foo" }	{ prod: "foo" }
Invocation Resulting environment webpack --env.prod --env.min { prod: true, min: true }	{ prod: true, min: true }
Invocation Resulting environment webpack --env.prod --env min [{ prod: true }, "min"]	[{ prod: true }, "min"]
Invocation Resulting environment webpack --env.prod=foo --env.prod=bar {prod: [ "foo", "bar" ]}	{prod: [ "foo", "bar" ]}

See the environment variables guide for more information on its usage.

Configuration Options

Parameter	Explanation	Input type	Default
Parameter Explanation Input type Default --config Path to the configuration file	Path to the configuration file	string	webpack.config.js or webpackfile.js
Parameter Explanation Input type Default --config-register, -r Preload one or more modules before loading the webpack configuration	Preload one or more modules before loading the webpack configuration	array
Parameter Explanation Input type Default --config-name Name of the configuration to use	Name of the configuration to use	string
Parameter Explanation Input type Default --env Environment passed to the configuration, when it is a function	Environment passed to the configuration, when it is a function
Parameter Explanation Input type Default --mode Mode to use	Mode to use	string	'production'

Output Options

This set of options allows you to manipulate certain output parameters of your build.

Parameter	Explanation	Input type	Default
Parameter Explanation Input type Default --output-chunk-filename The output filename for additional chunks	The output filename for additional chunks	string	filename with [ id ] instead of [ name ] or [ id ] prefixed
Parameter Explanation Input type Default --output-filename The output filename of the bundle	The output filename of the bundle	string	[name].js
Parameter Explanation Input type Default --output-jsonp-function The name of the JSONP function used for chunk loading	The name of the JSONP function used for chunk loading	string	webpackJsonp
Parameter Explanation Input type Default --output-library Expose the exports of the entry point as library	Expose the exports of the entry point as library	string
Parameter Explanation Input type Default --output-library-target The type for exposing the exports of the entry point as library	The type for exposing the exports of the entry point as library	string	var
Parameter Explanation Input type Default --output-path The output path for compilation assets	The output path for compilation assets	string	Current directory
Parameter Explanation Input type Default --output-pathinfo Include a comment with the request for every dependency	Include a comment with the request for every dependency	boolean	false
Parameter Explanation Input type Default --output-public-path The public path for the assets	The public path for the assets	string	/
Parameter Explanation Input type Default --output-source-map-filename The output filename for the SourceMap	The output filename for the SourceMap	string	[name].map or [outputFilename].map
Parameter Explanation Input type Default --build-delimiter Display custom text after build output	Display custom text after build output	string	Default string is null. You could provide a string such as === Build done ===

Example Usage

webpack index=./src/index.js index2=./src/index2.js --output-path='./dist' --output-filename='[name][hash].bundle.js'

| Asset                                | Size    | Chunks      | Chunk Names   |
|--------------------------------------|---------|-------------|---------------|
| index2740fdca26e9348bedbec.bundle.js |  2.6 kB | 0 [emitted] | index2        |
| index740fdca26e9348bedbec.bundle.js  | 2.59 kB | 1 [emitted] | index         |
	[0] ./src/others.js 29 bytes {0} {1} [built]
	[1] ./src/index.js 51 bytes {1} [built]
	[2] ./src/index2.js 54 bytes {0} [built]

webpack.js index=./src/index.js index2=./src/index2.js --output-path='./dist' --output-filename='[name][hash].bundle.js' --devtool source-map --output-source-map-filename='[name]123.map'

| Asset                                | Size    | Chunks      | Chunk Names   |
|--------------------------------------|---------|-------------|---------------|
| index2740fdca26e9348bedbec.bundle.js | 2.76 kB | 0 [emitted] | index2        |
|  index740fdca26e9348bedbec.bundle.js | 2.74 kB | 1 [emitted] | index         |
|                        index2123.map | 2.95 kB | 0 [emitted] | index2        |
|                         index123.map | 2.95 kB | 1 [emitted] | index         |
	[0] ./src/others.js 29 bytes {0} {1} [built]
	[1] ./src/index.js 51 bytes {1} [built]
	[2] ./src/index2.js 54 bytes {0} [built]

Debug Options

This set of options allows you to better debug the application containing assets compiled with webpack

Parameter	Explanation	Input type	Default value
Parameter Explanation Input type Default value --debug Switch loaders to debug mode	Switch loaders to debug mode	boolean	false
Parameter Explanation Input type Default value --devtool Define source map type for the bundled resources	Define source map type for the bundled resources	string	-
Parameter Explanation Input type Default value --progress Print compilation progress in percentage	Print compilation progress in percentage	boolean	false
Parameter Explanation Input type Default value --display-error-details Display details about errors	Display details about errors	boolean	false

Module Options

These options allow you to bind modules as allowed by webpack

Parameter	Explanation	Usage
Parameter Explanation Usage --module-bind Bind a file extension to a loader	Bind a file extension to a loader	--module-bind js=babel-loader
Parameter Explanation Usage --module-bind-post Bind a file extension to a post loader	Bind a file extension to a post loader
Parameter Explanation Usage --module-bind-pre Bind a file extension to a pre loader	Bind a file extension to a pre loader

Watch Options

These options make the build watch for changes in files of the dependency graph and perform the build again.

Parameter	Explanation
Parameter Explanation --watch, -w Watch the filesystem for changes	Watch the filesystem for changes
Parameter Explanation --watch-aggregate-timeout Timeout for gathering changes while watching	Timeout for gathering changes while watching
Parameter Explanation --watch-poll The polling interval for watching (also enable polling)	The polling interval for watching (also enable polling)
Parameter Explanation --watch-stdin, --stdin Exit the process when stdin is closed	Exit the process when stdin is closed

Optimize Options

These options allow you to manipulate optimizations for a production build using webpack

Parameter	Explanation	Plugin Used
Parameter Explanation Plugin Used --optimize-max-chunks Try to keep the chunk count below a limit	Try to keep the chunk count below a limit	LimitChunkCountPlugin
Parameter Explanation Plugin Used --optimize-min-chunk-size Try to keep the chunk size above a limit	Try to keep the chunk size above a limit	MinChunkSizePlugin
Parameter Explanation Plugin Used --optimize-minimize Minimize javascript and switches loaders to minimizing	Minimize javascript and switches loaders to minimizing	TerserPlugin

Resolve Options

These allow you to configure the webpack resolver with aliases and extensions.

Parameter	Explanation	Example
Parameter Explanation Example --resolve-alias Setup a module alias for resolving	Setup a module alias for resolving	--resolve-alias jquery-plugin=jquery.plugin
Parameter Explanation Example --resolve-extensions Setup extensions that should be used to resolve modules	Setup extensions that should be used to resolve modules	--resolve-extensions .es6 .js .ts
Parameter Explanation Example --resolve-loader-alias Minimize javascript and switches loaders to minimizing	Minimize javascript and switches loaders to minimizing

Stats Options

These options allow webpack to display various stats and style them differently in the console output.

Parameter	Explanation	Type
Parameter Explanation Type --color, --colors Force colors on the console [default: enabled for TTY output only]	Force colors on the console [ default: enabled for TTY output only ]	boolean
Parameter Explanation Type --no-color, --no-colors Force no colors on the console	Force no colors on the console	boolean
Parameter Explanation Type --display Select display preset (verbose, detailed, normal, minimal, errors-only, none; since webpack 3.0.0)	Select display preset (verbose, detailed, normal, minimal, errors-only, none; since webpack 3.0.0)	string
Parameter Explanation Type --display-cached Display also cached modules in the output	Display also cached modules in the output	boolean
Parameter Explanation Type --display-cached-assets Display also cached assets in the output	Display also cached assets in the output	boolean
Parameter Explanation Type --display-chunks Display chunks in the output	Display chunks in the output	boolean
Parameter Explanation Type --display-depth Display distance from entry point for each module	Display distance from entry point for each module	boolean
Parameter Explanation Type --display-entrypoints Display entry points in the output	Display entry points in the output	boolean
Parameter Explanation Type --display-error-details Display details about errors	Display details about errors	boolean
Parameter Explanation Type --display-exclude Exclude modules in the output	Exclude modules in the output	boolean
Parameter Explanation Type --display-max-modules Set the maximum number of visible modules in output	Set the maximum number of visible modules in output	number
Parameter Explanation Type --display-modules Display even excluded modules in the output	Display even excluded modules in the output	boolean
Parameter Explanation Type --display-optimization-bailout Scope hoisting fallback trigger (since webpack 3.0.0)	Scope hoisting fallback trigger (since webpack 3.0.0)	boolean
Parameter Explanation Type --display-origins Display origins of chunks in the output	Display origins of chunks in the output	boolean
Parameter Explanation Type --display-provided-exports Display information about exports provided from modules	Display information about exports provided from modules	boolean
Parameter Explanation Type --display-reasons Display reasons about module inclusion in the output	Display reasons about module inclusion in the output	boolean
Parameter Explanation Type --display-used-exports Display information about used exports in modules (Tree Shaking)	Display information about used exports in modules (Tree Shaking)	boolean
Parameter Explanation Type --hide-modules Hide info about modules	Hide info about modules	boolean
Parameter Explanation Type --sort-assets-by Sort the assets list by property in asset	Sort the assets list by property in asset	string
Parameter Explanation Type --sort-chunks-by Sort the chunks list by property in chunk	Sort the chunks list by property in chunk	string
Parameter Explanation Type --sort-modules-by Sort the modules list by property in module	Sort the modules list by property in module	string
Parameter Explanation Type --verbose Show more details	Show more details	boolean

Advanced Options

Parameter	Explanation	Usage
Parameter Explanation Usage --bail Abort the compilation on first error	Abort the compilation on first error
Parameter Explanation Usage --cache Enable in memory caching [Enabled by default for watch]	Enable in memory caching [ Enabled by default for watch ]	--cache=false
Parameter Explanation Usage --define Define any free variable, see shimming	Define any free variable, see shimming	--define process.env.NODE_ENV="'development'"
Parameter Explanation Usage --hot Enables Hot Module Replacement	Enables Hot Module Replacement	--hot=true
Parameter Explanation Usage --labeled-modules Enables labeled modules [Uses LabeledModulesPlugin]	Enables labeled modules [ Uses LabeledModulesPlugin ]
Parameter Explanation Usage --live-reload Enables live reloading	Enables live reloading	--live-reload=true
Parameter Explanation Usage --plugin Load this plugin	Load this plugin
Parameter Explanation Usage --prefetch Prefetch the particular file	Prefetch the particular file	--prefetch=./files.js
Parameter Explanation Usage --provide Provide these modules as globals, see shimming	Provide these modules as globals, see shimming	--provide jQuery=jquery
Parameter Explanation Usage --records-input-path Path to the records file (reading)	Path to the records file (reading)
Parameter Explanation Usage --records-output-path Path to the records file (writing)	Path to the records file (writing)
Parameter Explanation Usage --records-path Path to the records file	Path to the records file
Parameter Explanation Usage --target The targeted execution environment	The targeted execution environment	--target='node'

Shortcuts

Shortcut	Replaces
Shortcut Replaces -d --debug --devtool cheap-module-eval-source-map --output-pathinfo	--debug --devtool cheap-module-eval-source-map --output-pathinfo
Shortcut Replaces -p --mode production, see building for production	--mode production , see building for production

Profiling

The --profile option captures timing information for each step of the compilation and includes this in the output.

webpack --profile

⋮
[0] ./src/index.js 90 bytes {0} [built]
    factory:22ms building:16ms = 38ms

For each module, the following details are included in the output as applicable:

• factory: time to collect module metadata (e.g. resolving the filename)
• building: time to build the module (e.g. loaders and parsing)
• dependencies: time to identify and connect the module’s dependencies

Paired with --progress, --profile gives you an in-depth idea of which step in the compilation is taking how long. This can help you optimize your build in a more informed manner.

webpack --progress --profile

30ms building modules
1ms sealing
1ms optimizing
0ms basic module optimization
1ms module optimization
1ms advanced module optimization
0ms basic chunk optimization
0ms chunk optimization
1ms advanced chunk optimization
0ms module and chunk tree optimization
1ms module reviving
0ms module order optimization
1ms module id optimization
1ms chunk reviving
0ms chunk order optimization
1ms chunk id optimization
10ms hashing
0ms module assets processing
13ms chunk assets processing
1ms additional chunk assets processing
0ms recording
0ms additional asset processing
26ms chunk asset optimization
1ms asset optimization
6ms emitting
⋮

Pass CLI arguments to Node.js

To pass arguments directly to Node.js process, you can use the --node-args option. All other flags and options will be received by the webpack-cli.

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

webpack --node-args="--max-old-space-size=4096"

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

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