How to update webpack config for a react project created using create-react-app?

I have created a react project using create-react-app. Now I need to update the webpack config, but I don’t find the file anywhere.
Do I need to create this file myself or what is the process?
I am new to react and not really sure how to proceed from here.

No need to run npm run eject

Step 1

npm install react-app-rewired --save-dev

Step 2

Add config-overrides.js to the project root directory.(NOT ./src)

// config-overrides.js
module.exports = function override(config, env) {
    // New config, e.g. config.plugins.push...
    return config

Step 3

‘Flip’ the existing calls to react-scripts in npm scripts for start, build and test

/* package.json */
"scripts": {
    -   "start": "react-scripts start",
    +   "start": "react-app-rewired start",
    -   "build": "react-scripts build",
    +   "build": "react-app-rewired build",
    -   "test": "react-scripts test",
    +   "test": "react-app-rewired test",
        "eject": "react-scripts eject"

Step 4

Restart your app. Done

Option 1 – Eject your CRA

If you’ve just created your app using CRA, and haven’t made big changes to it, you could use npm run eject – more about it here

Keep in mind that there is no going back (except by commits, of course) after doing this. This will basically provide you with webpack file and other files which are currently ‘hidden’ in CRA

Some critiques and second thoughts about this method here

Option 2 – React App Rewired

This might be the right choice for you. This allows you to extend your current webpack without ejecting, or messing up / making too many changes at your project as npm run eject will. Take a look at the package here

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A great tutorial by using react-app-rewired here

I solved this problem by running a script between yarn install and yarn build. After yarn install the webpack.config.json file is generated, then immediately run a script on Node that modifies it, and then run the build.

My code:

const fs = require('fs')

// WebPack.config File
const fileConfig = 'node_modules/react-scripts/config/webpack.config.js'

new Promise((resolve) => {
   fs.readFile(fileConfig, 'utf8', function (err, data) {
      if (err) {
        return console.log(err)
}).then((file) => {
    let CodeAsString = "Code as String to save"

    let regexCode = /YourCodeRegex}/g

    let result = file.replace(regexCode, CodeAsString)

    fs.writeFile(fileConfig, result, function (err) {
        if (err) return console.log(err)
        console.log('The webpack.config file was modifed!')

So, now do you need to edit the package.json to include this code in the process:

"scripts": {
    "prestart": "node custom.webpack.config.js",
    "prebuild": "node custom.webpack.config.js",
    "start": "react-scripts start",
    "build": "react-scripts build"

Done! 🙂

Webpack configuration is being handled by react-scripts. I assume that you don’t want to eject and just want to look at the config, you will find them in /node_modules/react-scripts/config //used by `npm start` //used by `npm run build`

You can modify your webpack config or any other node_module using patch-package

Install the version of react-scripts you want with npm i [email protected]

Then go into node_modules/react-scripts/webpack/webpack.config.js. Make the changes you need and then npx patch-package react-scripts

patch-package will generate a file in your project root like patches/react-scripts+5.0.0.patch

Add post-install script to package.json with

"scripts": {
    "postinstall": "patch-package",

Now whenever you run npm i you will automatically get this patch included with the installed library.

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Complete answer is :

How to rewire your create-react-app project

Create your app using create-react-app and then rewire it.

  1. Install react-app-rewired
    For create-react-app 2.x with Webpack 4:
npm install react-app-rewired --save-dev

For create-react-app 1.x or react-scripts-ts with Webpack 3:

npm install [email protected] --save-dev
  1. Create a config-overrides.js file in the root directory
/* config-overrides.js */
module.exports = function override(config, env) {
  //do stuff with the webpack config...
  return config;

like this:

+-- your-project
|   +-- config-overrides.js
|   +-- node_modules
|   +-- package.json
|   +-- public
|   +--
|   +-- src

for example :

module.exports = function override(config, env) {
    // New config, e.g. config.plugins.push...

    config.module.rules = [...config.module.rules, 
            test: /\.m?js/,
            resolve: {
              fullySpecified: false

    return config
  1. ‘Flip’ the existing calls to react-scripts in npm scripts for start, build and test


/* package.json */

  "scripts": {
   "start": "react-scripts start",
   "build": "react-scripts build",
   "test": "react-scripts test",
   "eject": "react-scripts eject"


/* package.json */

  "scripts": {
   "start": "react-app-rewired start",
   "build": "react-app-rewired build",
   "test": "react-app-rewired test",
   "eject": "react-scripts eject"

Note: Do NOT flip the call for the eject script. That gets run only once for a project, after which you are given full control over the webpack configuration making react-app-rewired no longer required. There are no configuration options to rewire for the eject script.

  1. Start the Dev Server
npm start
  1. Build your app
npm run build

The best way is:

  1. Install react-app-rewired and customize-cra

  2. Create a config-overrides.js file in your root folder. Here is an example Webpack override file gist:

  3. Also, consider that you need to change react-scripts inside your package.json to react-app-rewired like:

    "start": "react-app-rewired start",
    "build": "react-app-rewired build",
    "test": "react-app-rewired test",
    "eject": "react-scripts eject"

You are ready to go

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The answers/resolutions are collected from stackoverflow, are licensed under cc by-sa 2.5 , cc by-sa 3.0 and cc by-sa 4.0 .

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