ZeroTest

To set up a ZeroTest instance, simply set up a Web server to host index.html over an unencrypted HTTP connection. (ZeroTest will not work if loaded over HTTPS, because restrictions on mixed content will block its requests.)

A public instance is available at https://zerotest.kj7rrv.com/; it uses the following Nginx configuration:

server {
    listen 80;
    listen [::]:80;
    server_name zerotest.kj7rrv.com;

    add_header Content-Security-Policy "connect-src 0.0.0.0:*;";

    root /var/www/zerotest;
    charset utf-8;
}

server {
    listen 443;
    listen [::]:443;
    server_name zerotest.kj7rrv.com;

    return 301 http://zerotest.kj7rrv.com;

    include /etc/nginx/templates/ssl.tmpl;
}

Note that if a Content Security Policy is set, it must allow fetch requests to all ports on 0.0.0.0; the header in the example Nginx configuration (connect-src 0.0.0.0:*;) works well.