SSL Fixer make your site HTTPS compatible without need to change any http (unsecure) URL even if your have external links
1) Replaces all internal urls from http to https
2) Replace all KNOWN ssl hosts from http to https (like fonts.googleapis.com). You can add more SSL host in the parameters
3) Fixes unsecure external hosts (domains without ssl support) fetching the content of resource (image/css)
4) Stores localy the unsecure external hosts resources (optionally)
5) Include / exlude trusted unsecure external hosts
Your website MUST HAVE active SSL (https) .