: Indicates that this specific file is unique to the developer's machine and must not be tracked by version control systems like Git . Environment Variable Load Order
This package ensures your database logic never accidentally ends up in client components. .env.development.local
Tools like Next.js follow a strict load order to determine which variable takes precedence. Generally, the more specific a file is, the higher its priority: : Indicates that this specific file is unique
If you are building a plain Node.js backend using Express, native environment loading of tiered files doesn't happen automatically. You will need a package like dotenv-flow instead of standard dotenv . javascript Generally, the more specific a file is, the
This file acts as the ultimate override for development-specific variables. When you run your application in development mode (typically via npm run dev or yarn start ), the system looks for variables across several files. In frameworks like Next.js, .env.development.local holds the . The typical hierarchy (from highest to lowest priority) is:
To prevent accidental leaking to the client, only variables prefixed with VITE_ are loaded (e.g., VITE_API_URL ). 3. Node.js (Vanilla)
Create a .env.example file with placeholder values for your team.