Minify your HTML by removing all the unnecessary characters.
Minify your JS by removing all the unnecessary characters.
Validate JSON content and make it looks good.
Get approximate IP details.
Find A, AAAA, CNAME, MX, NS, TXT, SOA DNS records of a host.
Get all possible details about an SSL certificate.
Get details of any file type, such as the mime type or last edit date.
Ping a website, server or port..