Minify your HTML by removing all the unnecessary characters.
Minify your JS by removing all the unnecessary characters.
Convert text to hexadecimal and the other way for any string input.
Take an IP and try to look for the domain/host associated with it.
Find A, AAAA, CNAME, MX, NS, TXT, SOA DNS records of a host.
Get all possible details about an SSL certificate.
Get all possible details about a domain name.
Generate passwords with custom length and custom settings.