Validates credit card numbers using the Luhn algorithm (ISO/IEC 7812). Identifies the card network (Visa, Mastercard, American Express, Discover, UnionPay, Maestro) from the BIN/IIN prefix. Accepts numbers with or without spaces/dashes. Useful for payment form validation testing and understanding card number structure.
Enter a card number to validate it with the Luhn algorithm and identify the card network.
Generate HMAC signatures using SHA-256, SHA-512, and other algorithms.
Check password strength against security criteria and estimate crack time.
Validate and parse International Bank Account Numbers (IBANs).
Validate ISBN-10 and ISBN-13 numbers and convert between them.
Encode text to hexadecimal or decode hex back to text.
Encrypt and decrypt text using the Caesar (ROT-N) substitution cipher.