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 approximate IP details.
Get all possible details about a domain name.
Ping a website, server or port..
Validate JSON content and make it looks good.
Get details of any file type, such as the mime type or last edit date.
Get all possible details about an SSL certificate.
Check whether or not a website is using the new HTTP/2 protocol or not.