How to switch the entire site to https while keeping the Search Engine indexed pages working?

Question

Magento 1.9.1 
Porto theme

Apparently Google will start penalizing sites that are not completely run on https.

I have 2 questions:

1. How to make it so that my entire site runs on https?

2. How NOT to loose any of the links that are already indexed by Google? I read that Google sees the same URL with http and https as 2 completely different things

Also we seem to have a problem with the

"Create Permanent Redirect for old URL".

I have that checked but Google found 922 Site not found Crawl Errors

they come up with a

"404 You might want to check that URL again or head over to our homepage."

Page on my site when you go to that URL.

We did change the category structure recently and I re-indexed everything after that.

When I go to CATALOG - URL REWRITE Management - it shows 330684 records. (I checked this a few days earlier and it had a Total 322505 records found which means an increase of 8000+ records in 2 days - why is that? What does this mean? And what do I need to do with it?)

Answer 1

If you add the following to your htaccess it will be seen as a valid 301

RewriteCond %{HTTPS} off
RewriteRule ^ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301,NE]

all this does is redirects http to https

Answer 2

First set the insecure base url to https:// Based on your setup this is enough to redirect the users if they try to use http://.

Maybe to redirect on web server level is better, as it avoids requests going through php first.

Next Thing

if you want a secure solution, you should add your website on https://hstspreload.appspot.com/ But be careful with this as changing the certificate can cause big problems. Let your Host to care about this part.