Make sure your passwords are good enough.
Find A, AAAA, CNAME, MX, NS, TXT, SOA DNS records of a host.
Generate an MD5 hash of 32 characters length for any string input.
Easily download any YouTube video thumbnail in all the available sizes.
Parse details from any URLs.
Validate JSON content and make it looks good.
Upload a QR code image and extract the data out of it.