How it works
Characters and words are drawn with crypto.getRandomValues, using rejection sampling so every symbol is exactly equally likely (a plain % n would slightly favour some). Each password is guaranteed to contain at least one character from every set you select.
Strength is measured as entropy: the number of guesses an attacker who knows your settings would need, as a power of two.
entropy = length × log2(alphabet size)
| Setting | Entropy |
|---|---|
| 20 characters, all 4 sets (≈ 88 symbols) | ≈ 129 bits |
| 12 characters, all 4 sets | ≈ 77 bits |
| 6 EFF words | ≈ 77.5 bits |
| 4 EFF words | ≈ 51.7 bits |
72+ bits is out of reach of offline cracking for the foreseeable future; prefer 100+ for keys that protect other secrets.
Passphrases
Passphrase mode uses the EFF Large Wordlist (7,776 words, CC BY 3.0 US): words that are easy to type and remember. Each word adds 12.9 bits.
Privacy
Settings are remembered; the generated passwords are not. They exist only in this page’s memory until you close it.