Convert text to binary and the other way for any string input.
Convert text to hexadecimal and the other way for any string input.
Convert text to ascii and the other way for any string input.
Convert text to octal and the other way for any string input.
Get all the HTTP headers that an URL returns for a typical GET request.
Find A, AAAA, CNAME, MX, NS, TXT, SOA DNS records of a host.
Get all possible details about an SSL certificate.
Ping a website, server or port..
Get approximate IP details.
Take an IP and try to look for the domain/host associated with it.