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 decimal and the other way for any string input.
Convert text to octal and the other way for any string input.
Make sure your passwords are good enough.
Compress and optimize images for a smaller image size but still high quality.
Check if the URL is banned and marked as safe/unsafe by Google.
Find A, AAAA, CNAME, MX, NS, TXT, SOA DNS records of a host.
Get details of any file type, such as the mime type or last edit date.
Get the web-host of a given website.