HTTPS Everywhere is a browser plugin for Firefox, Chrome, and Opera that keeps your website connection to certain well-known sites as a secure HTTPS. It is part of the Electronic Frontier Foundation’s (EFF) initiative to Encrypt the Web.
What does the plugin do?
Many sites on the web offer some encryption over HTTPS, but (as an example) do not easily make HTTPS available after its use on a login page. The HTTPS Everywhere extension fixes these problems for a set of major sites by rewriting all calls to the sites as HTTPS. Some of the thousands of supported sites are: Twitter, Facebook, Instagram, YouTube, Yahoo, and Amazon. If you are technical, the extension also allows you to add additional rulesets for more websites.
Why is it important?
The EFF explains that HTTPS “is essential in order to defend Internet users against surveillance of the content of their communications; cookie theft, account hijacking and other web security flaws; and some forms of Internet censorship.” You can read more about their mission here.