The performance benefits of rel=noopener for HTML a tag (and the security reminder)
▻https://jakearchibald.com/2016/performance-benefits-of-rel-noopener
Posted 21 July 2016 If you have links to another origin, you should use rel="noopener", especially if they open in a new tab/window.
Example site
Without this, the new page can access your window object via window.opener. Thankfully the origin security model of the web prevents it reading your page, but no-thankfully some legacy APIs mean it can navigate your page to a different URL using window.opener.location = newURL. Web superhero Mathias Bynens wrote about this in detail, but I just discovered there’s a performance benefit too. Demo
The random numbers act like a heartbeat for this page. If random numbers aren’t being generated every frame, something is holding up the thread. Now click one of these to open a page that runs some expensive JavaScript:
Without (...)