HTTPS Everywhere is a browser extension created by the Electronic Frontier Foundation (EFF) and the Tor Project. It encrypts your communications with many major websites, making your browsing more secure. HTTPS Everywhere automatically switches thousands of sites from insecure "http" to secure "https" to help users protect their data and privacy. It is available as a browser extension for Chrome, Firefox, Opera, and Android. HTTPS Everywhere is designed to protect users from man-in-the-middle attacks, eavesdropping, and other forms of surveillance by encrypting the traffic between the user and the website. It also blocks certain types of tracking and ensures that users are connected to the correct server. HTTPS Everywhere is free and open-source, and is designed to be easy to use and install.
HTTPS Everywhere and similar browser add-ons are available for Firefox, Chrome and Opera, but not for Safari. SSL Enforcer is the only way to get this important functionality when using Safari. An additional advantage is that it adds protection not only to my browser traffic, but also to other HTTP connections (email, plugins), as SSL Enforcer is an application that intercepts all insecure HTTP connections going to the predefined ports 80, 88, 3128, 8080-8088 for all applications.
Smart HTTPS
KB SSL Enforcer
ForceHTTPS
HTTP Nowhere
SSL Enforcer
ForceTLS
It is not a browser extension, but still works in the same way when running in the background of the system.