In the new pagespeed tool Google Lighthouse there is a hitherto unknown reference to a new attribute that seems to be important for Google. The tool advises to add the attribute rel=”noopener” to external links. Google classifies this in Lighthouse under the category “Best Practices”, because according to their information page there is a security problem, which can also affect the loading time if the attribute is not set.
Vulnerability with target=”_blank”
In order for users to stay longer on a potentially important page, you usually want the visitor to not leave the existing page after clicking on a link.
A remedy for this is the attribute target=”_blank” in the HTML anchor tag. This causes a new tab to open in the browser as soon as a link is clicked.
<a href=".../rel-noopener.html" target="_blank">Click me</a>
If everything worked correctly, this page should now have a red background.
Changing the background color on a source page is a harmless example. Possible scenarios that could also be executed include a redirect to a phishing page, a conversion of all links to another target page and much more…
It is important to know that this function will be executed even if the target page is on a different domain.
Now please reload the page once so that everything is back to normal. Reload Page
Solution with rel=”noopener”
<a href=".../rel-noopener.html" target="_blank" rel="noopener" >Click me</a>
As can be seen, the source page was not changed this time – although the same HTML file was called.
All external links that open the page in a new tab when clicked should have the rel=”noopener” attribute added.
Eiber SEO Expert +49 9381 5829037
Raymond Eiber is SEO Expert at eology GmbH. He advises SMEs as well as corporations on their positioning on the web and develops long-term SEO strategies for them.