If you view a Google cache of a website that is on a HTTPS URL, Google is starting to serve those cached pages under a secure connection. This means if your website is HTTPS, if someone views a cache of your page, that cache will now be served through a secure connection HTTPS URL to searchers.

Formerly, while Google’s actual search results are HTTPS and secure, if anyone clicks to view a cached version of the page from the search results, that cache would be unsecure, even if the page itself is actually secure.

Here is how it appears with the new secure cache link:

As you can see, the URL for the cache is now HTTPS instead of the usual HTTP.

While this might not seem like a big deal to some, such as for those who might only ever look at a page’s cache for spam reasons or to check how Googlebot is indexing and seeing a page.  But with more and more sites being taken down via DDOS for political reasons, it makes a lot of sense for Google to want to maintain a secure connection to those sites if a searcher is forced to view or use the cached version.

This is currently rolling out to users.  But if you view the cache page of a secure site, that Google cache URL will now be secure and start with HTTPS if it has rolled out to you.