Password Generator

Generate strong, random passwords with customizable length, character types, and strength analysis.

Uppercase letters (A-Z)
Lowercase letters (a-z)
Numbers (0-9)
Symbols (!@#$...)

Result

Fill in the fields above, then press Generate.

A password generator creates cryptographically random passwords with configurable length, character sets, and complexity requirements.

Set the desired password length, choose which character types to include, and specify how many passwords to generate. The calculator will produce random passwords and show their estimated strength.

Examples

16-character full charset

Using uppercase, lowercase, numbers, and symbols (95 chars): Entropy = 16 x log2(95) = 105 bits. Estimated crack time with 10 billion guesses/sec: trillions of years.

8-character lowercase only

Using only lowercase (26 chars): Entropy = 8 x log2(26) = 37.6 bits. This is weak and could be cracked in hours.

Frequently Asked Questions

What is password entropy?
Entropy measures the randomness (unpredictability) of a password in bits. Each bit doubles the number of possible combinations. A password with 80+ bits of entropy is considered strong against brute-force attacks.
How is crack time estimated?
Crack time assumes an attacker can try 10 billion passwords per second (a powerful GPU cluster). The estimate is the average time to find the password by brute force, which is half the total keyspace divided by the guess rate.
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Quick Tips

  • •Use at least 12 characters for good security.
  • •Include all character types for maximum entropy.
  • •Never reuse passwords across different accounts.
  • •Consider using a password manager to store generated passwords.