It shouldn't be a problem to login to a website opened via an open http:// connection. You can close possible insecure warnings via the ESC key. - - - - Firefox 51+ will mark HTTP connections with a padlock with a strike through and shows "Connection is Not Secure" if you click the Control Center 'i' button at the left end of the location/address bar. Note that this message is meant as a warning that you could be vulnerable and that it shouldn't prevent (block) you from accessing the website. You can press the ESC key to close a doorhanger with a warning message in the name and password field. You can disable the warning that opens when you type in a name/password field by setting this pref to false. *security.insecure_field_warning.contextual.enabled = false You can remove the warning in the location bar by setting this pref to false on the <b>about:config</b> page. *security.insecure_password.ui.enabled = false See also: *https://support.mozilla.org/en-US/kb/insecure-password-warning-firefox *https://support.mozilla.org/en-US/kb/how-do-i-tell-if-my-connection-is-secure *https://support.mozilla.org/en-US/kb/what-does-your-connection-is-not-secure-mean