How to Enable HTTPS Only Mode in Firefox Browser

Version 76.0 of the popular Firefox web browser has a new feature using which you can disable all the non-secure web traffic. It has an “HTTPS Only Mode” which can be enabled to block access to the sites that are still being served over the old insecure HTTP connections.

For the same effect (blocking insecure connections), we had to install extensions like “HTTPS Everywhere” in Firefox before this new feature was added by Mozilla. Now we do not have to depend on any extension because HTTPS only mode comes built inside Firefox itself.

Here is a simple way to enable (or disable) this HTTPS only mode in Firefox:

  1. Launch Firefox browser, type about:config in the address bar and press Enter.
  2. After a brief warning screen, you will find the advanced preferences screen. Search for HTTPS to narrow down the list of preferences that we want to change.
  3. Locate a preference named and double-click on it to change its value from false to true.Firefox HTTPS Only Mode
  4. This is it, now Firefox won’t access any website over HTTP. Of course, you can disable it later in the same manner if needed.

One problem with enabling strict HTTPS only mode is that websites that offer mixed content won’t load all of their content and might appear broken. For example, some images might be missing on such mixed content webpages. A website that is served only through HTTP will simply fail to load and Firefox will complain of not being to able to connect to that site’s web server.

Needless to mention that if you do not find this preference, then you are perhaps using an older version of Firefox and have to update your copy of Firefox to the latest version available. While the version 76.0 will be automatically delivered to your computer, you may speed up the process by downloading the new version from and installing it yourself.