Next.js automatically loads .env.development for next dev . Variables must start with NEXT_PUBLIC_ to be exposed to the browser [StackOverflow, 2021].
Master .env.development: The Ultimate Guide to Environment Configuration
Never copy production secrets, real user data, or live encryption keys into .env.development . Use sandbox environments, local test databases, and mock APIs exclusively. Troubleshooting Common Issues Variables Return 'undefined' .env.development
Both tools have built-in support.
Most modern frameworks (React with Vite, Next.js, Vue, Node.js with dotenv, Django, Laravel, etc.) support the following file precedence: Use sandbox environments, local test databases, and mock
// config-loader.js const dotenv = require('dotenv'); dotenv.config( path: '.env' ); // Base dotenv.config( path: `.env.$process.env.NODE_ENV` ); // .env.development dotenv.config( path: `.env.local` ); // Local overrides
Different frameworks have adopted the .env.development pattern with their own conventions. if (process
if (process.env.NODE_ENV === 'development') apiUrl = 'http://localhost:8000'; else if (process.env.NODE_ENV === 'production') apiUrl = 'https://api.myapp.com';