Help:Extension:SecureLinkFixer

The SecureLinkFixer extension automatically rewrites some URLs to use HTTPS.

Which domains?
The domain list comes from Mozilla's HSTS preload list. Websites can submit themselves to be added. You can see the list of domains in Gerrit (warning: large page).

How to add a new domain?
Website operators can submit themselves to be added to the HSTS preload list.