Last night, Google’s Matt Cutts posted on Twitter about HSTS, a protocol that tells web browsers to use HTTPS instead of the HTTP URLs to access your web pages.

But shortly after that, Gary Illyes from Google, said be careful doing that. Gary is the one who coded the Google HTTPS algorithm and he said, only use HSTS if your HTTPS is properly configured. If you do not have properly configured HTTPS web site and you go the HSTS route, it can cause indexing issues with Google.

Gary wrote on Twitter, “Make sure your site fully supports https when you implement HSTS tho. Weird stuff happen in indexing when it doesn’t.”

So just be careful there.

Forum discussion at Twitter.

Update: Matt Cutts posted on Twitter this morning: