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.
Upload a QR code image and extract the data out of it.
Make sure your passwords are good enough.
Get approximate IP details.
Check whether a website is using the new HTTP/2 protocol or not.
Find A, AAAA, CNAME, MX, NS, TXT, SOA DNS records of a host.
Parse details from any URLs.