Email Address
[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}
Matches valid email addresses
Strong Password
^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)[a-zA-Z\d@$!%*?&]{8,}$
At least 8 chars, uppercase, lowercase, number
Phone Number
^\+?[1-9]\d{1,14}$
International phone number format
URL
^https?://...
Matches HTTP and HTTPS URLs
IP Address
^(?:(?:25[0-5]|2[0-4][0-9]...)$
Matches IPv4 addresses
Username
^[a-zA-Z0-9_-]{3,16}$
3-16 chars, letters, numbers, underscore, dash
Hex Color
^#([A-Fa-f0-9]{6}|[A-Fa-f0-9]{3})$
Matches hex color codes
Credit Card
\b\d{4}[-]?\d{4}[-]?\d{4}[-]?\d{4}\b
16-digit credit card numbers