Firefox developers have continued the development of the “” mode, which, when enabled, automatically redirects all unencrypted requests to their secure page counterparts (replacing “http://” with “https://”). In the nightly builds, from which the Firefox 80 release will be formed on August 25, the interface for configuring browser settings (about:preferences) now includes a section under “Privacy and Security” for managing the activation of HTTPS-only browsing. to enable this mode for all windows or only for those opened in private browsing mode. By default, the redirection to HTTPS is turned off.
Let’s recall that the new mode addresses the issue of opening default pages using “http://”, without the option to change this behavior. Despite significant efforts to promote HTTPS in browsers, typing a domain in the address bar without specifying the protocol still defaults to “http://”. The proposed setting alters this behavior, as well as enabling automatic replacement to “https://” when entering an address with “http://”. In addition to replacing input in the address bar, switching to HTTPS is also performed at the level of sub-resources loaded on the pages.
If the request to primary pages (domain input in the address bar) on https:// times out, the user sees an error page that includes a button to make the request via http://. In cases where there are failures when loading sub-resources via “https://” during page processing, such failures are ignored, but warnings are output to the web console, which can be viewed through developer tools.
Source: opennet.ru
