How to disable open browser in CRA?

Add BROWSER=none to your npm start script in your package.json file, like this:

"scripts": {
  "start": "BROWSER=none react-scripts start",
  "build": "react-scripts build",
  "test": "react-scripts test",
  "eject": "react-scripts eject"
},

Check out the CRA documentation for more configuration and environment variable options:

https://create-react-app.dev/docs/advanced-configuration/

---

Update/Troubleshooting:

In case you're having a 'BROWSER' is not recognized as an internal or external command, operable program or batch file error: do an npm install of cross-env:

npm install --save cross-env

Then, add cross-env BROWSER=none to your start script

"start": "cross-env BROWSER=none react-scripts start",

I suggest doing it at the command level, so you don't have to change any files that get committed.

BROWSER=none npm start

You can add an alias for this to your shell's configuration:

alias myapp-start='cd /path/to/myapp && BROWSER=none npm start'

Create .env file in the root directory where your package.json file resides. And add the following:

BROWSER=none

Now run npm start.

For Windows you can edit/create a script in package.json like this one:

"start": "set BROWSER=none && react-scripts start"

For Linux based OS, just delete the "set" and the "&&" and it will work:

"start": "BROWSER=none react-scripts start"