How to Hide API Keys in Frontend Code

Reynaldi • January 10, 2026

Hiding an API key in frontend code isn’t something you can do directly. In this guide, you’ll learn how to do it using a backend proxy and why it’s the only real solution.

Use a Backend Proxy (Recommended)

Use Corsfix as your backend proxy to hide API keys in your frontend code. Setup takes less than a minute, and you’re ready to secure your credentials.

// Your frontend code (API key hidden)
fetch("https://proxy.corsfix.com/?https://api.example.com/data", {
  headers: {
    "Authorization": "Bearer {{API_KEY}}"
  }
});

// Corsfix inserts the real key server-side
// Your users never see the actual API key

Code example for hiding API key in frontend

Instead of exposing your actual API key, you pass in a variable name for your secret. Corsfix stores your key server-side and injects it into requests, keeping it hidden from your frontend.

Set up your secrets in the Corsfix dashboard, and reference them using the {{SECRET_NAME}} syntax.

Why Can’t I Hide an API Key in Frontend?

Without a backend proxy, there’s no way to truly hide an API key since anything in the browser is accessible to users. If you include an API key directly in your frontend code, anyone can view it by inspecting your website’s source code or network requests.

Some guides suggest using environment variables, but if your code runs client-side, those values are still bundled into your frontend and exposed. The only real way to hide an API key is to keep it on a backend server.

Hosting Your Own Backend Proxy

While Corsfix offers a backend proxy service for this exact use case, you also have the option to host your own backend. Instead of using your API key in the frontend code, you would store it in your backend server and have your frontend call this backend instead.

This means you’ll need to handle your own infrastructure, manage different HTTP methods, deal with authentication headers, ensure your server stays online, and handle ongoing maintenance.

Conclusion

Use Corsfix as your backend proxy to hide API keys from your frontend code. Understand that hiding API keys directly in frontend code is not possible without a server-side solution.

Try Corsfix for free and start securing your API keys now.