How can I set NODE_ENV=production on Windows?

It would be ideal if you could set parameters on the same line as your call to start Node.js on Windows. Look at the following carefully, and run it exactly as stated:

You have these two options:

1. At the command line:

   set NODE_ENV=production&&npm start
   

   or

   set NODE_ENV=production&&node index.js
   

2. The trick for it to work on Windows is you need to remove the whitespace before and after the "&&". Configured your package.json file with start_windows (see below) below. Then Run "npm run start_windows" at the command line.

   //package.json
   
   "scripts": {
     "start": "node index.js"
     "start_windows": "set NODE_ENV=production&&node index.js"
   }
   

I just found a nice Node.js package that can help a lot to define environment variables using a unique syntax, cross platform.

https://www.npmjs.com/package/cross-env

It allow you to write something like this:

cross-env NODE_ENV=production my-command

Which is pretty convenient! No Windows or Unix specific commands any more!

In PowerShell:

$env:NODE_ENV="production"

Current versions of Windows use Powershell as the default shell, so use:

$env:NODE_ENV="production"

Per @jsalonen's answer below. If you're in CMD (which is no longer maintained), use

set NODE_ENV=production

This should be executed in the command prompt where you intend to run your Node.js application.

The above line would set the environment variable NODE_ENV for the command prompt where you execute the command.

To set environment variables globally so they persist beyond just the single command prompt, you can find the tool from System in Control Panel (or by typing 'environment' into the search box in the start menu).