The site is actually spinning up a VM to run the nmap so those progress bars are real. Thanks for checking. I reached out to the creator and he will update it

The site is actually spinning up a VM to run the nmap so those progress bars are real. Thanks for checking. I reached out to the creator and he will update it to work with IPv6. Agree nmap from another machine is best but that's not always an option. I'm thinking like if I am on hotel wifi or something. I might not have easy access to another box. Shodan is a great suggestion.