.env.development (2026)

Here is the golden rule: Anything in a browser-facing .env.development is public. A user can open DevTools and see your REACT_APP_ variables. Never, ever put an admin password, database URI, or private key in a frontend .env.development file. Use a backend proxy instead.

Once you have mastered the basics, you can explore advanced techniques that leverage the full power of .env.development.

The Power of .env.development: Streamlining Your Development Environment

As developers, we often juggle multiple environments, from local development to production. Managing environment-specific configurations can become a nightmare, leading to errors and frustration. That's where .env.development comes to the rescue!

What is .env.development?

.env.development is a configuration file used by many development tools and frameworks, including Node.js, React, and Next.js. It's a simple text file that stores environment-specific variables, such as API keys, database connections, and other sensitive data.

Why use .env.development?

By using .env.development, you can:

How does .env.development work?

Here's a breakdown of the process:

Best practices for .env.development

Example .env.development file

Here's an example .env.development file for a Node.js project: .env.development

DB_HOST=localhost
DB_PORT=5432
DB_USERNAME=myuser
DB_PASSWORD=mypassword
API_KEY=your_api_key_here

Conclusion

.env.development is a powerful tool for managing environment-specific configurations. By using this file, you can simplify your development workflow, keep sensitive data secure, and improve collaboration with your team. Give it a try and see the benefits for yourself!

References

In modern web development, .env.development is a configuration file used to store non-sensitive

environment-specific variables that only apply when running an application in "development mode". Stack Overflow

Here is a breakdown of how to "produce a feature" using this file: 1. Identify Your Environment Variables .env.development Here is the golden rule: Anything in a browser-facing

to define variables that differ from your production or testing environments. Common examples include: : Points to a local or staging server (e.g., API_BASE_URL=http://localhost:5000 Feature Flags : Enables experimental features only for developers (e.g., ENABLE_NEW_DASHBOARD=true Debug Modes : Controls the verbosity of logs. Stack Overflow 2. Configure the File Create a file named .env.development in your project's root directory. For frameworks like Create React App

, your variables must often follow a specific prefix to be accessible in the browser: Create React App : Prefix with REACT_APP_ REACT_APP_API_URL : Prefix with VITE_API_URL Stack Overflow 3. Load the Variables Most modern frameworks automatically detect .env.development when you run commands like . For a standard Node.js project, you can use the dotenv package to load specific files manually: javascript // Load environment-specific file ).config({ path: process.env.NODE_ENV Use code with caution. Copied to clipboard 4. Implement the Feature in Code Access these variables via process.env to toggle features or change behavior dynamically. Stack Overflow Example Implementation: javascript apiUrl = process.env.REACT_APP_API_URL; // Feature toggle based on env variable (process.env.REACT_APP_ENABLE_BETA_UI === ) showBetaFeatures(); Use code with caution. Copied to clipboard 5. Best Practices

Multiple .env files, encrypting secrets, and committing .env to code

While .env.development is currently the standard, the ecosystem is evolving.

However, for the vast majority of developers—from solo freelancers to large teams—the simplicity and transparency of .env.development remain the gold standard.