In modern web development, managing sensitive data such as API keys, database credentials, and various configurations for different environments is essential. Storing these variables directly in code can pose security risks and complicate deployment. Vite, a modern front-end build tool, provides a straightforward way to manage environment variables through .env files.

What is a .env File?

A .env file is a simple configuration file used to define environment-specific variables. These variables can be accessed within your application while remaining separate from the source code. This practice allows for easy management of different environments—development, staging, and production—without hardcoding sensitive data.

Environment Variables in Vite:

Vite comes with built-in support for environment variables, making it easier to inject different values based on the current environment. Here’s how Vite handles environment variables:

Global Variables: Vite injects environment variables at build time.
Prefixed Variables: Only variables prefixed with VITE_ are exposed to the client-side JavaScript code for security reasons. Any variables not prefixed this way won’t be accessible in the browser.

Example of a Vite environment variable:

VITE_API_URL=https://api.example.com

Setting Up .env Files in Vite
Vite supports multiple .env files, allowing you to define environment variables for specific environments. Here’s a typical setup:

.env: Default file for environment variables shared across all environments.
.env.development: Variables specific to the development environment.
.env.production: Variables specific to the production environment.

Example .env File:

VITE_API_URL=https://api.example.com
VITE_APP_NAME=MyViteApp

Example .env.development File:

VITE_API_URL=http://localhost:3000
VITE_DEBUG_MODE=true

Example .env.production File:

VITE_API_URL=https://api.production.com
VITE_DEBUG_MODE=false

Accessing Environment Variables in Vite

To access environment variables inside your Vite project, use the import.meta.env object.

console.log(import.meta.env.VITE_API_URL); // Outputs the value of VITE_API_URL

Vite automatically replaces import.meta.env values during the build process based on the current environment.

Managing Multiple Environments:

Vite’s .env files can be customized for different environments like development, staging, and production. Depending on which environment you're in, Vite will load the appropriate .env file:

Running vite loads the .env.development file.
Running vite build loads the .env.production file.
Running in a specific environment:

vite --mode staging

Debugging Environment Variables:

If you’re having issues with environment variables not working as expected, check the following:

• Variable Prefix: Ensure all client-side variables have the VITE_ prefix, as Vite ignores variables without this prefix.
• Env Loading Order: Make sure .env and environment-specific files are in the project root and named correctly.
• Check Build Process: Use console.log(import.meta.env) to see all available environment variables during development.

Conclusion::

Vite’s built-in support for environment variables through .env files makes it easy to manage configurations across different environments.