Unsafe external links checker

What is an Unsafe External Links Checker?

The Unsafe External Links Checker finds links pointing to other domains that are missing rel="noopener" or rel="noreferrer", which protect against a known browser vulnerability called reverse tabnabbing.

What Is Reverse Tabnabbing?

• The exploit — When a link uses target="_blank" without rel="noopener", the newly opened page can access window.opener and silently redirect the original tab to a phishing page.
• Simple fix — Adding rel="noopener noreferrer" to any external link that opens in a new tab closes this gap entirely.
• Modern browsers help — Recent browser versions apply noopener behavior by default for target="_blank" links, but explicitly setting it remains best practice for compatibility.