Password Generator

Generate strong, random, cryptographically secure passwords. Configure length and character sets — everything runs in your browser using crypto.getRandomValues.






Estimated entropy

What "strong" actually means

Password strength is measured in bits of entropy. Each random character drawn from an alphabet of N options contributes log₂(N) bits of entropy. So a 12-character password from a 94-character pool (uppercase + lowercase + digits + symbols) has 12 × log₂(94) ≈ 78.7 bits — far beyond practical brute-force reach.

EntropyPractical strength
under 40 bitsWeak — crackable in hours by a single GPU
40–60 bitsOK for low-stakes accounts with rate limiting
60–80 bitsStrong — sufficient for almost all online accounts
80+ bitsVery strong — appropriate for password manager master keys

Tips for managing strong passwords

Frequently asked questions

Why is the "every set" checkbox useful?

Without it, a 12-character random password could in theory contain only lowercase letters (very low probability, but possible). The checkbox guarantees the password contains at least one uppercase, one lowercase, one digit, and one symbol — meeting the most common password complexity rules.

Can I trust this more than a random "password generator" website?

The math is the same as long as the source of randomness is good. This tool uses crypto.getRandomValues, which delegates to the operating system's secure RNG. To be sure no one tampered with the page, you can read the source (View Source in your browser) before generating, or run it offline.

Are passphrases (5 random words) better than random characters?

For a given strength, passphrases are generally longer but easier to type. Five truly random words from a 7,776-word dictionary have 64.6 bits of entropy — roughly equivalent to a 10-character symbol-rich password. We may add a passphrase generator in a future update.