πŸ“¦ webpack secrets

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What webpack secrets or less commonly known features do you know? This also includes loaders or plugins that not everyone might be aware of. Please share so we can all become webpack enlightened. πŸ˜‰

I'll start. Did you know that you can write your webpack config in TypeScript if you have the ts-node dev dependency installed? Type checking for my webpack config? Yes please!

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webpack-shell-plugin allows you to run arbitrary shell commands as part of your build. We've used this for a couple of complicated file-moving maneuvers that webpack would've otherwise choked on a bit.


Thanks for the share Dane! This looks very handy.


This is very edge-case & specific but I spent days on this problem.

If you compile your assets on multiple servers and use @svgr/webpack, sometimes it can build 2 different hashes for a single compiled js asset, based on some attributes (or empty attributes) in svg elements, which causes inconsistent bundle names across multiple servers who all run the build step on their own. This causes unfortunate bundle app-[hash].js not found errors on the client side.

The trick to solving this is to disable svgo

test: /\.(svg)$/,
use: [
    loader: '@svgr/webpack',
    options: {
      svgo: false

webpack bundle analyzer
It's a cool tool which generates a zoomable tree map showing what's inside your JavaScript bundle - size of each dependency ( and dependencies of dependencies recursively ) in minified, un-minified and gzipped format.
Setup is fairly simple, do give it a try.

GitHub logo webpack-contrib / webpack-bundle-analyzer

Webpack plugin and CLI utility that represents bundle content as convenient interactive zoomable treemap

npm node deps tests downloads

Webpack Bundle Analyzer

Visualize size of webpack output files with an interactive zoomable treemap.


npm install --save-dev webpack-bundle-analyzer
# Yarn
yarn add -D webpack-bundle-analyzer

Usage (as a plugin)

const BundleAnalyzerPlugin = require('webpack-bundle-analyzer').BundleAnalyzerPlugin
module.exports = {
  plugins: [
    new BundleAnalyzerPlugin()

It will create an interactive treemap visualization of the contents of all your bundles.

webpack bundle analyzer zoomable treemap

This module will help you:

  1. Realize what's really inside your bundle
  2. Find out what modules make up the most of its size
  3. Find modules that got there by mistake
  4. Optimize it!

And the best thing is it supports minified bundles! It parses them to get real size of bundled modules And it also shows their gzipped sizes!

Options (for plugin)

new BundleAnalyzerPlugin(options?: object)
Name Type Description
analyzerMode One of: server, static, disabled Default: server. In server

Yeah that's a great one. We have it setup on react-slingshot. πŸ”₯


For those using TypeScript, the Fork TS Checker Webpack plugin is a must for any somewhat large project.

It allows you to run the TypeScript type checker in a separate process which results in faster builds.

Realytics / fork-ts-checker-webpack-plugin

Webpack plugin that runs typescript type checker on a separate process.

Fork TS Checker Webpack Plugin

Npm version Build Status

Webpack plugin that runs typescript type checker on a separate process.


This plugin requires minimum webpack 2.3, typescript 2.1 and optionally tslint 4.0

npm install --save-dev fork-ts-checker-webpack-plugin

Basic webpack config (with ts-loader)

var ForkTsCheckerWebpackPlugin = require('fork-ts-checker-webpack-plugin')
var webpackConfig = {
  context: __dirname, // to automatically find tsconfig.json
  entry: './src/index.ts'
  module: {
    rules: [
        test: /\.tsx?$/
        loader: 'ts-loader',
        options: {
          // disable type checker - we will use it in fork plugin
          transpileOnly: true 
  plugins: [
    new ForkTsCheckerWebpackPlugin()


There is already similar solution - awesome-typescript-loader. You can add CheckerPlugin and delegate checker to the separate process. The problem with awesome-typescript-loader was that, in our case it…

Where I used to work, we had a very large project and it brought down the initial webpack build time from 2 minutes to 25-30 seconds.

And it looks like they also have an alpha out for webpack 5.


I usually find maintaining webpack configurations difficult. With either splitting prod and development configs or conditionally do some stuff based on an environment, that can get messy real quick.

I've been using the following for configuring some parts based on the environment for instance. I feel it has been keeping most of the config terse and easier to read.

GitHub logo kentcdodds / webpack-config-utils

Utilities to help your webpack config be easier to read


Utilities to help your webpack config be easier to read

Build Status Code Coverage Dependencies version downloads MIT License

All Contributors PRs Welcome Donate Code of Conduct Roadmap Examples

The problem

Webpack configuration is a JavaScript object which is awesomely declarative. However, the webpack config file can easily turn into an imperative mess in the process of creating the configuration object.

This solution

The goal of this project is to provide utilities to make it easier to compose your config object so it's easier for people to read. It has some custom methods and also comes bundled with some other projects to expose some helpful utility functions.


This module is distributed via npm which is bundled with node and should be installed as one of your project's devDependencies:

npm install --save-dev webpack-config-utils


It is expected that you use this in your webpack.config.js file.

Protip: You can name your config file webpack.config.babel.js and it'll be automagically transpiled! (Make sure you have babel-register installed.) So you could…


Thanks for sharing Thomas. πŸ”₯ Is there anything Kent C. Dodds can't do? πŸ˜‚

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Just some dev at DEV. Big fan of TypeScript, (P)React JavaScript and Node. C#/asp.net once upon a time.