Security is a central topic, especially when it comes to protecting user data and privacy. A simple but effective method to increase the security of your website is the use of the HTML attribute rel=noopener. This attribute can prevent malicious scripts from accessing your web page when users click on external links that open in a new tab. But how exactly does this work, and what benefits does it offer? In this article, we take a detailed look at the function, security benefits, and SEO context of this attribute.

What is rel=noopener?

The rel=noopener attribute is an addition to links in HTML that ensures the window.opener function is disabled. This JavaScript function normally allows a linked page to access the original page that contains the link. This can potentially be dangerous, especially with external links, as malicious pages could use this function to access information from the source page. By adding rel=noopener, this risk is effectively prevented.

Function of rel=noopener

When you create a link that should open in a new tab – for example, with the attribute target="_blank" – the linked page receives access to the source page via the window.opener function. This means that the linked page could theoretically execute JavaScript to read data from the source page or even inject malicious code.

rel=noopener disables this function and ensures that the source page remains protected from possible attacks. It is therefore an additional security measure that is particularly useful for external links.

Security Benefits of rel=noopener

The main goal of rel=noopener is to minimize security risks that can arise from external links. Here are some of the most important benefits:

  1. Protection against Cross-Site Hacking: Malicious pages can no longer access the source page, preventing cross-site scripting attacks.
  2. Enhanced Privacy: Since no information is passed from the source page to the linked page, user privacy is protected.
  3. Close Security Gap with target="_blank": The combination of target="_blank" and rel=noopener closes a known security vulnerability that hackers could otherwise exploit.

These measures significantly improve the security of your website and your users' data.

rel=noopener and SEO

A frequently asked question is whether rel=noopener has an impact on SEO ranking. The good news: The attribute has no negative effects on your SEO efforts. It is purely a security measure that has no direct connection to search engine ranking factors. You can therefore use it without hesitation, without having to worry that it will affect your position in search results.

When Should You Use rel=noopener?

The attribute is particularly useful for external links that open in a new tab. Internal links that lead to other pages within the same website generally do not require such a security measure, as there is no risk of an unknown page accessing your information.

To ensure that your website is always optimally protected, it is recommended to add rel=noopener to all external links. Many content management systems (CMS) like WordPress even offer plugins that automatically handle this task. This saves time and ensures that no external links are overlooked.

rel=noreferrer: A Complement to rel=noopener

Another relevant attribute in this context is rel=noreferrer. This attribute behaves similarly to rel=noopener, but goes one step further. In addition to protecting against window.opener attacks, rel=noreferrer prevents referrer information from being transmitted to the linked page. This means that the linked page cannot see which page the click came from.

Using rel=noreferrer

This attribute is useful if you want to protect your users' privacy even further. However, there are certain situations where rel=noreferrer is not ideal, especially in affiliate marketing. Here, referrer information is crucial for properly attributing traffic and conversions. If rel=noreferrer is used, tracking systems may not be able to track commissions, which would be disadvantageous for affiliate programs.

Combination of Attributes: Noopener, Noreferrer, and Nofollow

It is entirely possible to use multiple attributes simultaneously to achieve different goals:

  • rel=noopener: Protects against cross-site hacking.
  • rel=noreferrer: Prevents the transmission of referrer data.
  • rel=nofollow: Ensures that search engines do not follow the link and thus it does not pass on SEO value.

These combinations can be useful depending on the context to optimize both security and SEO goals.

Tools for Implementing rel=noopener

Many content management systems like WordPress offer plugins that allow you to automatically insert the rel=noopener attribute into your external links. This not only saves time but also ensures that no links are overlooked that could potentially pose a security risk. Among the most well-known plugins are Yoast SEO and WP External Links, both of which offer a user-friendly interface and enable implementation of the attribute without technical know-how.

Cross-Origin Resource Sharing (CORS) and rel=noopener noreferrer

Another important security aspect is protection against Cross-Origin Resource Sharing (CORS) attacks. These attacks occur when malicious websites attempt to access resources or data from another domain. By using rel=noopener noreferrer, the risk of such attacks is significantly reduced, as the linked page cannot access the source page and no referrer information is transmitted.

Conclusion: Simple Measures for More Security

Adding rel=noopener to your external links is a simple but extremely effective method to increase the security of your website. It protects your users from potential security threats while also helping to preserve privacy. Especially in combination with other attributes like rel=noreferrer and rel=nofollow, you can optimally secure your website without worrying about negative effects on your SEO.

By correctly applying these attributes, you create a more secure and trustworthy online experience for your users.