webpack-dev-server
Serves a webpack app. Updates the browser on changes. Documentation https://webpack.js.org/configuration/dev-server/.
Top Related Projects
Set up a modern web app by running one command.
The zero configuration build tool for the web. 📦🚀
Next generation frontend tooling. It's fast!
The React Framework
The Intuitive Vue Framework.
ESM-powered frontend build tool. Instant, lightweight, unbundled development. ✌️
Quick Overview
Webpack Dev Server is a development server that provides live reloading functionality for webpack applications. It serves the files from memory and automatically updates the browser when changes are detected, making it an essential tool for developers working on webpack-based projects.
Pros
- Live reloading: Automatically refreshes the browser when changes are made to the source code
- Hot Module Replacement (HMR): Allows updating modules in the browser without a full page reload
- Configurable: Offers extensive configuration options to customize the development environment
- Integration with webpack: Seamlessly works with webpack's ecosystem and plugins
Cons
- Learning curve: Can be complex to set up and configure for beginners
- Performance overhead: May slow down the development process for large projects
- Limited production use: Primarily designed for development environments, not suitable for production deployments
- Dependency on webpack: Requires webpack as a core dependency, which may not be ideal for all projects
Code Examples
- Basic configuration:
const path = require('path');
module.exports = {
devServer: {
static: {
directory: path.join(__dirname, 'public'),
},
compress: true,
port: 9000,
},
};
This example sets up a basic dev server configuration, serving static files from the 'public' directory, enabling compression, and setting the port to 9000.
- Enabling Hot Module Replacement:
module.exports = {
devServer: {
hot: true,
},
};
This configuration enables Hot Module Replacement, allowing for module updates without a full page reload.
- Proxying API requests:
module.exports = {
devServer: {
proxy: {
'/api': 'http://localhost:3000',
},
},
};
This example sets up a proxy for API requests, forwarding requests starting with '/api' to a backend server running on localhost:3000.
Getting Started
To get started with webpack-dev-server:
-
Install the necessary packages:
npm install webpack webpack-cli webpack-dev-server --save-dev
-
Add a script to your
package.json
:"scripts": { "start": "webpack serve --open" }
-
Create a basic webpack configuration file (
webpack.config.js
):const path = require('path'); module.exports = { mode: 'development', entry: './src/index.js', output: { filename: 'main.js', path: path.resolve(__dirname, 'dist'), }, devServer: { static: { directory: path.join(__dirname, 'dist'), }, compress: true, port: 8080, }, };
-
Run the dev server:
npm start
This will start the webpack-dev-server and open your default browser to the served application.
Competitor Comparisons
Set up a modern web app by running one command.
Pros of Create React App
- Provides a complete, opinionated setup for React projects out of the box
- Abstracts away complex configuration, allowing developers to focus on writing code
- Includes built-in optimizations and best practices for production builds
Cons of Create React App
- Less flexibility in configuration compared to webpack-dev-server
- May include unnecessary dependencies for simpler projects
- Updating to newer versions can be challenging due to potential breaking changes
Code Comparison
Create React App:
npx create-react-app my-app
cd my-app
npm start
webpack-dev-server:
const webpack = require('webpack');
const WebpackDevServer = require('webpack-dev-server');
const config = require('./webpack.config.js');
const server = new WebpackDevServer(webpack(config), {
// ... configuration options
});
server.listen(8080, 'localhost', () => {
console.log('Dev server listening on port 8080');
});
Create React App provides a simpler setup process, while webpack-dev-server offers more granular control over the development environment. The choice between the two depends on project requirements and developer preferences.
The zero configuration build tool for the web. 📦🚀
Pros of Parcel
- Zero configuration required for most projects, making it easier to set up and use
- Faster build times due to its multi-core processing and caching mechanisms
- Built-in support for various file types and assets without additional plugins
Cons of Parcel
- Less flexibility and customization options compared to webpack-dev-server
- Smaller ecosystem and community support
- May struggle with more complex project configurations
Code Comparison
webpack-dev-server configuration:
module.exports = {
devServer: {
contentBase: './dist',
hot: true,
port: 8080
}
};
Parcel (no configuration required):
parcel index.html
Key Differences
- webpack-dev-server requires explicit configuration, while Parcel works out of the box
- webpack-dev-server offers more granular control over the development environment
- Parcel automatically handles most common scenarios without additional setup
Use Cases
- webpack-dev-server: Large-scale applications with complex build requirements
- Parcel: Smaller projects or rapid prototyping where quick setup is prioritized
Community and Ecosystem
- webpack-dev-server has a larger community and more extensive plugin ecosystem
- Parcel has a growing community but fewer third-party integrations available
Performance
- Parcel generally offers faster initial build times
- webpack-dev-server may have better long-term performance for larger projects
Next generation frontend tooling. It's fast!
Pros of Vite
- Significantly faster build and reload times due to native ES modules
- No bundling required in development, leading to quicker startup
- Simpler configuration and easier to set up for new projects
Cons of Vite
- Less mature ecosystem and plugin availability compared to webpack
- May require additional configuration for older browsers or non-ESM dependencies
- Limited support for certain advanced webpack features
Code Comparison
webpack-dev-server configuration:
module.exports = {
devServer: {
contentBase: './dist',
hot: true,
port: 8080
}
};
Vite configuration:
export default {
server: {
port: 3000,
open: true
}
};
Both webpack-dev-server and Vite are popular development servers for modern web applications. Webpack-dev-server has been the go-to choice for many years, offering a robust ecosystem and extensive plugin support. Vite, on the other hand, is a newer entrant that focuses on speed and simplicity.
Vite leverages native ES modules, resulting in faster build times and near-instantaneous hot module replacement. It requires minimal configuration and is particularly well-suited for modern JavaScript frameworks. However, its ecosystem is less mature, and it may require additional setup for older browsers or complex build scenarios.
Webpack-dev-server, while generally slower, offers more flexibility and a wider range of features. It has better support for older browsers and non-ESM dependencies out of the box. The choice between the two often depends on project requirements, team familiarity, and performance needs.
The React Framework
Pros of Next.js
- Provides a complete framework for React applications, including routing, server-side rendering, and API routes
- Offers automatic code splitting and optimized performance out of the box
- Supports static site generation and incremental static regeneration
Cons of Next.js
- Steeper learning curve due to its opinionated structure and additional concepts
- Less flexibility in configuration compared to webpack-dev-server
- May be overkill for simple single-page applications
Code Comparison
Next.js:
// pages/index.js
export default function Home() {
return <h1>Welcome to Next.js!</h1>
}
webpack-dev-server:
// webpack.config.js
module.exports = {
devServer: {
contentBase: './dist',
hot: true
}
};
Next.js provides a more streamlined development experience with its file-based routing system and built-in server-side rendering capabilities. webpack-dev-server, on the other hand, offers greater flexibility and customization options for development environments but requires more manual configuration.
While Next.js is better suited for large-scale React applications with complex routing and server-side rendering needs, webpack-dev-server is ideal for developers who want fine-grained control over their build process and development setup.
The Intuitive Vue Framework.
Pros of Nuxt
- Full-featured framework with built-in routing, state management, and server-side rendering
- Automatic code splitting and optimized performance out of the box
- Extensive ecosystem with plugins and modules for easy feature integration
Cons of Nuxt
- Steeper learning curve for developers new to Vue.js or SSR concepts
- Less flexibility in configuration compared to webpack-dev-server's customization options
- Potentially larger bundle size due to included features, even if not all are used
Code Comparison
Nuxt configuration:
export default {
modules: ['@nuxtjs/axios'],
build: {
transpile: ['vue-echarts', 'resize-detector']
}
}
webpack-dev-server configuration:
module.exports = {
devServer: {
contentBase: './dist',
hot: true,
proxy: {
'/api': 'http://localhost:3000'
}
}
}
Key Differences
- Nuxt provides a higher-level abstraction, focusing on rapid development of Vue.js applications
- webpack-dev-server offers more granular control over the development environment
- Nuxt includes server-side rendering capabilities, while webpack-dev-server is primarily for client-side development
- Nuxt has a more opinionated structure, whereas webpack-dev-server allows for more flexible project organization
ESM-powered frontend build tool. Instant, lightweight, unbundled development. ✌️
Pros of Snowpack
- Faster development builds due to unbundled development
- Simpler configuration and setup process
- Built-in support for modern web technologies like ES modules
Cons of Snowpack
- Less mature ecosystem and community support
- May require additional plugins for certain features
- Potential compatibility issues with older browsers in production
Code Comparison
Snowpack configuration:
// snowpack.config.js
module.exports = {
mount: {
public: '/',
src: '/dist',
},
};
webpack-dev-server configuration:
// webpack.config.js
module.exports = {
devServer: {
contentBase: './dist',
hot: true,
},
};
Both Snowpack and webpack-dev-server are popular development server solutions for modern web applications. Snowpack focuses on leveraging native ES modules for faster development builds and a simpler configuration process. It excels in projects using modern web technologies but may require additional setup for older browser support.
webpack-dev-server, part of the webpack ecosystem, offers a more mature and battle-tested solution with extensive plugin support and broader compatibility. However, it can be more complex to configure and may have slower build times for larger projects.
The choice between the two depends on project requirements, team familiarity, and specific use cases. Snowpack is ideal for modern, fast-paced development, while webpack-dev-server provides a robust solution for a wide range of project types and configurations.
Convert designs to code with AI
Introducing Visual Copilot: A new AI model to turn Figma designs to high quality code using your components.
Try Visual CopilotREADME
webpack-dev-server
Use webpack with a development server that provides live reloading. This should be used for development only.
It uses webpack-dev-middleware under the hood, which provides fast in-memory access to the webpack assets.
Table of Contents
Getting Started
First things first, install the module:
npm install webpack-dev-server --save-dev
or
yarn add -D webpack-dev-server
or
pnpm add -D webpack-dev-server
Note: While you can install and run webpack-dev-server globally, we recommend installing it locally. webpack-dev-server will always use a local installation over a global one.
Usage
There are two main, recommended methods of using the module:
With the CLI
The easiest way to use it is with the webpack CLI. In the directory where your
webpack.config.js
is, run:
npx webpack serve
Following options are available with webpack serve
:
Usage: webpack serve|server|s [entries...] [options]
Run the webpack dev server.
Options:
-c, --config <value...> Provide path to a webpack configuration file e.g. ./webpack.config.js.
--config-name <value...> Name of the configuration to use.
-m, --merge Merge two or more configurations using 'webpack-merge'.
--disable-interpret Disable interpret for loading the config file.
--env <value...> Environment passed to the configuration when it is a function.
--node-env <value> Sets process.env.NODE_ENV to the specified value.
--define-process-env-node-env <value> Sets process.env.NODE_ENV to the specified value. (Currently an alias for `--node-env`)
--analyze It invokes webpack-bundle-analyzer plugin to get bundle information.
--progress [value] Print compilation progress during build.
-j, --json [value] Prints result as JSON or store it in a file.
--fail-on-warnings Stop webpack-cli process with non-zero exit code on warnings from webpack
-d, --devtool <value> A developer tool to enhance debugging (false | eval | [inline-|hidden-|eval-][nosources-][cheap-[module-]]source-map).
--no-devtool Negative 'devtool' option.
--entry <value...> A module that is loaded upon startup. Only the last one is exported.
--mode <value> Enable production optimizations or development hints.
--name <value> Name of the configuration. Used when loading multiple configurations.
-o, --output-path <value> The output directory as **absolute path** (required).
--stats [value] Stats options object or preset name.
--no-stats Negative 'stats' option.
-t, --target <value...> Environment to build for. Environment to build for. An array of environments to build for all of them when possible.
--no-target Negative 'target' option.
--watch-options-stdin Stop watching when stdin stream has ended.
--no-watch-options-stdin Negative 'watch-options-stdin' option.
--allowed-hosts <value...> Allows to enumerate the hosts from which access to the dev server are allowed (useful when you are proxying dev server, by default is 'auto').
--allowed-hosts-reset Clear all items provided in 'allowedHosts' configuration. Allows to enumerate the hosts from which access to the dev server are allowed (useful when you are proxying dev server, by default is 'auto').
--bonjour Allows to broadcasts dev server via ZeroConf networking on start.
--no-bonjour Disallows to broadcasts dev server via ZeroConf networking on start.
--no-client Disables client script.
--client-logging <value> Allows to set log level in the browser.
--client-overlay Enables a full-screen overlay in the browser when there are compiler errors or warnings.
--no-client-overlay Disables the full-screen overlay in the browser when there are compiler errors or warnings.
--client-overlay-errors Enables a full-screen overlay in the browser when there are compiler errors.
--no-client-overlay-errors Disables the full-screen overlay in the browser when there are compiler errors.
--client-overlay-warnings Enables a full-screen overlay in the browser when there are compiler warnings.
--no-client-overlay-warnings Disables the full-screen overlay in the browser when there are compiler warnings.
--client-overlay-runtime-errors Enables a full-screen overlay in the browser when there are uncaught runtime errors.
--no-client-overlay-runtime-errors Disables the full-screen overlay in the browser when there are uncaught runtime errors.
--client-overlay-trusted-types-policy-name <value> The name of a Trusted Types policy for the overlay. Defaults to 'webpack-dev-server#overlay'.
--client-progress Prints compilation progress in percentage in the browser.
--no-client-progress Does not print compilation progress in percentage in the browser.
--client-reconnect [value] Tells dev-server the number of times it should try to reconnect the client.
--no-client-reconnect Tells dev-server to not to try to reconnect the client.
--client-web-socket-transport <value> Allows to set custom web socket transport to communicate with dev server.
--client-web-socket-url <value> Allows to specify URL to web socket server (useful when you're proxying dev server and client script does not always know where to connect to).
--client-web-socket-url-hostname <value> Tells clients connected to devServer to use the provided hostname.
--client-web-socket-url-pathname <value> Tells clients connected to devServer to use the provided path to connect.
--client-web-socket-url-password <value> Tells clients connected to devServer to use the provided password to authenticate.
--client-web-socket-url-port <value> Tells clients connected to devServer to use the provided port.
--client-web-socket-url-protocol <value> Tells clients connected to devServer to use the provided protocol.
--client-web-socket-url-username <value> Tells clients connected to devServer to use the provided username to authenticate.
--compress Enables gzip compression for everything served.
--no-compress Disables gzip compression for everything served.
--history-api-fallback Allows to proxy requests through a specified index page (by default 'index.html'), useful for Single Page Applications that utilise the HTML5 History API.
--no-history-api-fallback Disallows to proxy requests through a specified index page.
--host <value> Allows to specify a hostname to use.
--hot [value] Enables Hot Module Replacement.
--no-hot Disables Hot Module Replacement.
--ipc [value] Listen to a unix socket.
--live-reload Enables reload/refresh the page(s) when file changes are detected (enabled by default).
--no-live-reload Disables reload/refresh the page(s) when file changes are detected (enabled by default).
--open [value...] Allows to configure dev server to open the browser(s) and page(s) after server had been started (set it to true to open your default browser).
--no-open Does not open the default browser.
--open-target <value...> Opens specified page in browser.
--open-app-name <value...> Open specified browser.
--open-reset Clear all items provided in 'open' configuration. Allows to configure dev server to open the browser(s) and page(s) after server had been started (set it to true to open your default browser).
--open-target-reset Clear all items provided in 'open.target' configuration. Opens specified page in browser.
--open-app-name-reset Clear all items provided in 'open.app.name' configuration. Open specified browser.
--port <value> Allows to specify a port to use.
--server-type <value> Allows to set server and options (by default 'http').
--server-options-passphrase <value> Passphrase for a pfx file.
--server-options-request-cert Request for an SSL certificate.
--no-server-options-request-cert Does not request for an SSL certificate.
--server-options-ca <value...> Path to an SSL CA certificate or content of an SSL CA certificate.
--server-options-ca-reset Clear all items provided in 'server.options.ca' configuration. Path to an SSL CA certificate or content of an SSL CA certificate.
--server-options-cert <value...> Path to an SSL certificate or content of an SSL certificate.
--server-options-cert-reset Clear all items provided in 'server.options.cert' configuration. Path to an SSL certificate or content of an SSL certificate.
--server-options-crl <value...> Path to PEM formatted CRLs (Certificate Revocation Lists) or content of PEM formatted CRLs (Certificate Revocation Lists).
--server-options-crl-reset Clear all items provided in 'server.options.crl' configuration. Path to PEM formatted CRLs (Certificate Revocation Lists) or content of PEM formatted CRLs (Certificate Revocation Lists).
--server-options-key <value...> Path to an SSL key or content of an SSL key.
--server-options-key-reset Clear all items provided in 'server.options.key' configuration. Path to an SSL key or content of an SSL key.
--server-options-pfx <value...> Path to an SSL pfx file or content of an SSL pfx file.
--server-options-pfx-reset Clear all items provided in 'server.options.pfx' configuration. Path to an SSL pfx file or content of an SSL pfx file.
--static [value...] Allows to configure options for serving static files from directory (by default 'public' directory).
--no-static Disallows to configure options for serving static files from directory.
--static-directory <value...> Directory for static contents.
--static-public-path <value...> The static files will be available in the browser under this public path.
--static-serve-index Tells dev server to use serveIndex middleware when enabled.
--no-static-serve-index Does not tell dev server to use serveIndex middleware.
--static-watch Watches for files in static content directory.
--no-static-watch Does not watch for files in static content directory.
--static-reset Clear all items provided in 'static' configuration. Allows to configure options for serving static files from directory (by default 'public' directory).
--static-public-path-reset Clear all items provided in 'static.publicPath' configuration. The static files will be available in the browser under this public path.
--watch-files <value...> Allows to configure list of globs/directories/files to watch for file changes.
--watch-files-reset Clear all items provided in 'watchFiles' configuration. Allows to configure list of globs/directories/files to watch for file changes.
--no-web-socket-server Disallows to set web socket server and options.
--web-socket-server-type <value> Allows to set web socket server and options (by default 'ws').
Global options:
--color Enable colors on console.
--no-color Disable colors on console.
-v, --version Output the version number of 'webpack', 'webpack-cli' and 'webpack-dev-server' and commands.
-h, --help [verbose] Display help for commands and options.
To see list of all supported commands and options run 'webpack --help=verbose'.
Webpack documentation: https://webpack.js.org/.
CLI documentation: https://webpack.js.org/api/cli/.
Made with ⥠by the webpack team.
[!NOTE]
Detailed documentation for above options is available on this link.
With NPM Scripts
NPM package.json scripts are a convenient and useful means to run locally installed binaries without having to be concerned about their full paths. Simply define a script as such:
{
"scripts": {
"serve": "webpack serve"
}
}
And run the following in your terminal/console:
npm run serve
NPM will automatically refer to the the binary in node_modules
for you, and
execute the file or command.
With the API
While it's recommended to run webpack-dev-server via the CLI, you may also choose to start a server via the API.
See the related API documentation for webpack-dev-server
.
With TypeScript
If you use TypeScript in the webpack config, you'll need to properly type devServer
property in order to avoid TS errors (e.g. 'devServer' does not exist in type 'Configuration'
). For that use either:
/// <reference path="node_modules/webpack-dev-server/types/lib/Server.d.ts"/>
import type { Configuration } from "webpack";
// Your logic
Or you can import the type from webpack-dev-server
, i.e.
import type { Configuration as DevServerConfiguration } from "webpack-dev-server";
import type { Configuration } from "webpack";
const devServer: DevServerConfiguration = {};
const config: Configuration = { devServer };
// module.exports
export default config;
The Result
Either method will start a server instance and begin listening for connections
from localhost
on port 8080
.
webpack-dev-server is configured by default to support live-reload of files as you edit your assets while the server is running.
See the documentation for more use cases and options.
Browser Support
While webpack-dev-server
transpiles the client (browser) scripts to an ES5
state, the project only officially supports the last two versions of major
browsers. We simply don't have the resources to support every whacky
browser out there.
If you find a bug with an obscure / old browser, we would actively welcome a Pull Request to resolve the bug.
Support
We do our best to keep issues in the repository focused on bugs, features, and needed modifications to the code for the module. Because of that, we ask users with general support, "how-to", or "why isn't this working" questions to try one of the other support channels that are available.
Your first-stop-shop for support for webpack-dev-server should be the excellent documentation for the module. If you see an opportunity for improvement of those docs, please head over to the webpack.js.org repo and open a pull request.
From there, we encourage users to visit the webpack discussions and
talk to the fine folks there. If your quest for answers comes up dry in chat,
head over to StackOverflow and do a quick search or open a new
question. Remember; It's always much easier to answer questions that include your
webpack.config.js
and relevant files!
If you're twitter-savvy you can tweet #webpack with your question and someone should be able to reach out and lend a hand.
If you have discovered a :bug:, have a feature suggestion, or would like to see a modification, please feel free to create an issue on Github. Note: The issue template isn't optional, so please be sure not to remove it, and please fill it out completely.
Contributing
We welcome your contributions! Please have a read of CONTRIBUTING.md for more information on how to get involved.
Attribution
This project is heavily inspired by peerigon/nof5.
License
MIT
Top Related Projects
Set up a modern web app by running one command.
The zero configuration build tool for the web. 📦🚀
Next generation frontend tooling. It's fast!
The React Framework
The Intuitive Vue Framework.
ESM-powered frontend build tool. Instant, lightweight, unbundled development. ✌️
Convert designs to code with AI
Introducing Visual Copilot: A new AI model to turn Figma designs to high quality code using your components.
Try Visual Copilot