The rel="noopener" attribute in HTML is used with <a> tags to enhance security when opening links in a new tab or window. Here's a breakdown:

  • Purpose: It prevents the new window or tab from accessing the original page's window.opener object. Without noopener, the new page could potentially manipulate the original page (e.g., redirect it to a malicious site) using JavaScript.

  • How It Works: When you include rel="noopener" in a link like <a href="example.com" target="_blank" rel="noopener">, it ensures the new page cannot access or control the original page through the window.opener property.

  • Use Case: Always use rel="noopener" with target="_blank" links, especially for external sites, to protect users from potential security risks like phishing attacks.

  • Browser Support: Most modern browsers (since around 2017) support noopener. Some browsers even apply it automatically now, but it's still good practice to include it for compatibility and clarity.

Example:

<a href="https://example.com" target="_blank" rel="noopener">Visit Example</a>

It’s a small but important security measure!