Do you put Babel and Webpack in devDependencies or Dependencies?

The babel and webpack packages will go into the devDependencies section because these packages are used in when transpiling and bundle-ing your code into vanilla javascript in the bundle.js & etc file(s).

In production you will run your code off the bundle.js build/generated code will not require these dependencies anymore.

Despite what basically everyone says, I'm going to offer a piece of sanity... it's really quite simple:

Is your project going to be npm installed by another project? a.k.a are you authoring a npm module? will it end up in another projects package.json?

No?

Then put everything in dependencies.

Yes?

• dependencies: Things you want downstream consumers and project developers of your project to have installed:
• peerDependencies: Things your downstream users need to make sure they have installed
• bundleDependencies: Things your downstream users will need, and won't need to install separately because when you npm publish, these will be "bundled" with your package.
• optionalDependencies: Things that are nice to have but the absence of will not cause fatal error
• devDependencies: things only used while working on your project.

The short of it is this: modules do not magically get installed differently. They either get installed or they do not.

Dev dependency is which only use for the development server, these are devDepedency:All the packages which are not using in source code or imported are devDependencies

"babel-cli": "^6.26.0","babel-core": "^6.26.0","babel-loader": "^7.1.4","babel-preset-env": "^1.6.1","babel-preset-react": "^6.24.1","clean-webpack-plugin": "^0.1.19","copy-webpack-plugin": "^4.5.1","css-loader": "^0.28.11","file-loader": "^1.1.11","html-webpack-plugin": "^3.2.0","mini-css-extract-plugin": "^0.4.0","node-sass": "^4.8.3","optimize-css-assets-webpack-plugin": "^4.0.0","prop-types": "^15.6.1","sass-loader": "^7.0.1","style-loader": "^0.21.0","uglifyjs-webpack-plugin": "^1.2.5","webpack": "^4.6.0","webpack-cli": "^3.1.1","webpack-dev-server": "^3.1.9"