.env.development Jun 2026

If you'd like to share (e.g., Next.js, Create React App, Vue), I can provide the exact naming conventions for your environment variables!

⚠️ Many frameworks require a specific prefix to expose variables to the browser. Required Prefix Vite VITE_ VITE_API_URL=http://localhost:3000 Next.js NEXT_PUBLIC_ NEXT_PUBLIC_ANALYTICS_ID=dev_123 React (CRA) REACT_APP_ REACT_APP_SECRET_KEY=dev_secret 3. Protect Your Data

Understanding this hierarchy ensures that your local configurations don't accidentally overwrite critical settings. While specific order varies slightly by tool, the standard priority from generally looks like this:

: Even though it's "for development," you must never include real secrets (like production database passwords or private API keys) in this file if it is committed to GitHub. .env.development

PORT=3000 DATABASE_URL=mongodb://localhost:27017/my_dev_db API_SECRET=dev_mock_key_123 DEBUG=true Use code with caution. Troubleshooting Common Issues

Proper .gitignore configuration is crucial. The recommended approach is:

const handleSearch = async (query) => // This call is proxied through our secure API route const response = await fetch( $apiBaseUrl/search?q=$query ); return response.json(); ; // ... If you'd like to share (e

Always ensure your .gitignore file is properly configured before you push code to GitHub or GitLab. Your project's .gitignore should explicitly block local secret overrides:

Use .local files for machine-specific overrides (e.g., local API keys).

: Avoid writing KEY = value . Write KEY=value instead. Protect Your Data Understanding this hierarchy ensures that

: For development mode ( next dev ), the priority is: process.env (runtime environment) → .env.development.local → .env.local → .env.development → .env .

: Double-check that your framework requires a specific prefix (e.g., NEXT_PUBLIC_ for Next.js or REACT_APP_ for React) to expose variables to the browser.

Here is an example of a .env.development file: