Password Generator - Generate Strong Random Passwords
Generate strong, random passwords with configurable length and character types. Ideal for test data, filling test accounts and generating secure passwords. Everything runs in your browser.
Note:All generated data is entirely fictional and not suitable for use as real personal information.
Tips for strong passwords
- Use at least 16 characters for optimal security.
- Combine all character types: uppercase, lowercase, numbers and special characters.
- Use a unique password for each account.
- Consider a password manager to securely store all your passwords.
Password Entropy: How Randomness Determines Strength
Password strength is measured in entropy bits — the number of binary choices an attacker must make to guess the password. More entropy means exponentially longer cracking time.
| Character set | Size | 12-char entropy | 16-char entropy |
|---|---|---|---|
| Lowercase only | 26 | 56 bits | 75 bits |
| Lower + uppercase | 52 | 68 bits | 91 bits |
| Lower + upper + digits | 62 | 71 bits | 95 bits |
| All characters (full set) | 95 | 78 bits | 105 bits |
NIST recommends a minimum of 80 bits of entropy for high-security applications. A 16-character password using the full character set (95 printable ASCII characters) provides 105 bits — well above that threshold.
Testing Password Policies in Software Development
A password generator is a core utility when building or testing authentication systems. Here are the most common developer use cases.
- Policy validation testing — generate passwords that meet and violate specific policies (minimum length, required character types) to verify your validation logic handles all edge cases correctly.
- Test account seeding — generate unique random passwords for test user accounts in staging and CI environments instead of reusing weak or predictable passwords across accounts.
- Password hashing benchmarks — test bcrypt, Argon2, and scrypt cost factors against passwords of varying length and complexity to find the right performance/security balance for your hardware.
- API key and secret generation — use high-entropy random strings as API keys, webhook secrets, or session tokens in test environments where cryptographic key generation libraries are not available.
For complete test user profiles, combine passwords with fictional email addresses and names using the dataset generator.
Password Security Standards: NIST and OWASP Guidelines
Modern password security guidelines have shifted significantly over the past decade. The two most widely referenced standards are NIST SP 800-63B and the OWASP Authentication Cheat Sheet.
- NIST SP 800-63B — recommends a minimum length of 8 characters (15 for high-security systems), no mandatory complexity rules, and checking passwords against known-breach lists. Periodic forced resets are no longer recommended.
- OWASP — recommends minimum 8 characters, support for all ASCII characters including spaces, no truncation, and rate limiting or account lockout after failed attempts.
- Length over complexity — both NIST and OWASP now emphasize length as the primary driver of password strength rather than mandatory special characters, which often lead to predictable substitutions.
This generator follows these guidelines: it supports all character types, allows lengths from 8 to 128, and generates passwords using cryptographically secure randomness.