NEXT_PUBLIC_APP_URL=https://myapp.com API_URL=https://api.myapp.com
However, due to developer confusion or legacy configuration scripts, you will occasionally find the inverted version: .
Explain how to using process.env . Let me know how you'd like to proceed . .env.local.production
Frameworks like Next.js and Vite look for environment variables in a strict order of inheritance. Variables defined higher in the hierarchy override variables defined lower down. Here is the standard priority order from highest to lowest:
Sometimes, a bug only manifests when the application is compiled and optimized for production. To debug it, you run commands like next build && next start or vite build && vite preview on your machine. NEXT_PUBLIC_APP_URL=https://myapp
Do not accidentally put highly sensitive credentials (like private database passwords) into variables prefixed for the client side within your .env.local.production file. Summary Comparison Commit to Git? Environment Context .env Default settings for all environments .env.local Local overrides for all environments .env.production Production defaults for the whole team Production only .env.local.production Local production overrides on your machine No Production only
: It allows a developer to test a production build locally with specific credentials without changing the shared .env.production file. Frameworks like Next
NODE_ENV=production npm run build
# .env DOMAIN=example.com ADMIN_EMAIL=admin@$DOMAIN # Becomes admin@example.com
Avoid spreading configuration logic across your codebase. Create a single module (e.g., lib/env.ts or config.js ) that reads process.env , validates it, and exports it. All other parts of your application should import from this module.
This file allows you to simulate a production environment without touching real production secrets.