Vite env values returning undefined [SOLVED]

The Problem

Vite is a modern build tool for web development, especially now that CRA (create-react-app) is being officially deprecated, it’s becoming even more popular.

When working with Vite, you might encounter an issue where your environment variables are returning undefined, even though you’ve properly set them up in your .env file. This can be frustrating, especially when you’re sure you’ve followed all the basic setup steps correctly.

Common Pitfalls

1. Incorrect Variable Prefix
2. Accessing Variables Directly
3. import.meta.env Usage
4. Placing .env file in the wrong directory

The Solution

Here’s how to properly set up and access environment variables in Vite:

1. Use VITE_ prefix in environemnt variables

In Vite, environment variables need to be prefixed with VITE_ to be exposed to your application.

Here’s how it’s explained in official doc:

To prevent accidentally leaking env variables to the client, only variables prefixed with VITE_ are exposed to your Vite-processed code. e.g. for the following env variables:

For example:

# ✅ This is accessible in the client code
VITE_API_KEY=your_api_key

# ❌ This is not accessible in the client code, will return undefined
API_KEY=your_api_key

2. Accessing Variables

In Vite, importing environment variables work a bit different then other build tools. We should access environment variables using import.meta.env, not process.env:

// ✅ Correct way
const apiKey = import.meta.env.VITE_API_KEY;

// ❌ Wrong way, value will be undefined
const apiKey = process.env.VITE_API_KEY;

3. TypeScript Configuration

If you’re using TypeScript, you might need to add type definitions for your environment variables:

/// <reference types="vite/client" />

interface ImportMetaEnv {
  readonly VITE_API_KEY: string;
  // Add other env variables here
}

interface ImportMeta {
  readonly env: ImportMetaEnv;
}

4. Placing .env file in the wrong directory

If you’re using a .env file, make sure it’s placed in the root directory of your project, and not in the src or any other directory directory.

Additional Tips

1. Development vs Production: Remember that Vite handles environment variables differently in development and production. If you need more complex environment variables handling, check out the official docs.
2. Variable Replacement: Vite replaces environment variables during build time, not runtime.
3. Security Considerations: Only variables prefixed with VITE_ are exposed to your client-side code.

Common Debugging Steps

If you’re still having issues, and your environment variables in Vite returning undefined, try the following:

1. Check if your .env file is in the root directory
2. Verify the VITE_ prefix
3. Restart your development server
4. Check your vite.config.js for any custom environment variable handling

Conclusion

Understanding how Vite handles environment variables is crucial for proper application configuration. By following these guidelines, you can avoid the common pitfall of undefined environment variables and ensure your application has access to the configuration it needs.