If you want to setup a site with HTTPS, you need a valid SSL certificate from Certificate Authority (CA). Let's Encrypt is a CA that can provide you a free valid SSL certificate by requesting it using certain software. The software which is recommended by Let's Encrypt is Certbot . From the main page of Certbot site, you can choose what web server and operating system you use then it will show you the installation steps. For example, I use Nginx on Ubuntu 16.04. $ sudo apt-get install software-properties-common $ sudo add-apt-repository ppa:certbot/certbot $ sudo apt-get update $ sudo apt-get install python-certbot-nginx $ certbot --nginx Last command will get a certificate for you and have Certbot edit your Nginx configuration automatically to serve it. Sometimes, you may get error notes. It is about failure of integration process to existing web server configuration. It's not crucial cause you can integrate manually with simple steps. If you only want to get cer