Each character is drawn from window.crypto.getRandomValues — the browser's cryptographically secure random source, the same one used for TLS session keys. That is far stronger than Math.random and matches the entropy expected by password managers and security audits.

For most accounts a 16-character password with uppercase, lowercase, numbers and symbols comfortably exceeds 80 bits of entropy and resists offline cracking. Vault master passwords and root credentials benefit from 24+ characters; throwaway burner accounts can use fewer.

Strength is estimated as length × log₂(character pool size), expressed in bits. Anything above ~80 bits is considered safe against offline brute force for the foreseeable future. Removing character classes shrinks the pool, so the bit count drops accordingly.

In theory yes, but the probability is astronomically small for any reasonable length. A 16-character mixed-class password has roughly 10^31 possible values — the chance of accidental collision is far smaller than the chance of a hardware failure.

Enable "Exclude similar" (i, l, 1, L, o, 0, O) when the password will be transcribed by hand or read over the phone to avoid mix-ups. Enable "Exclude ambiguous" ({} [] () /\ '"`,;:.) when the password must paste cleanly into terminals or shell scripts.

No. Generation happens entirely on your device and recent passwords live in memory until you reload the tab. Nothing is sent over the network, nothing is logged and nothing is cached.

Yes. Turn on "Exclude similar" to drop the characters that get confused on screen or over the phone (i, l, 1, L, o, 0, O), and turn on "Exclude ambiguous" to drop brackets, slashes and quotes that are awkward to type. Then raise the length a few characters to keep the entropy where you want it.

Switch the mode toggle from 'Random characters' to 'Passphrase (words)' — the generator then builds a password from several random dictionary words (EFF Diceware wordlist) instead of scrambled characters, which is easier to remember and type but still cryptographically strong.

The default of 6 words gives roughly 77 bits of entropy, the EFF-recommended minimum for a strong passphrase. Drag the Words slider higher (up to the maximum) for a master password protecting a password manager or crypto wallet, or lower for a passphrase you'll type frequently on a low-risk account.

Yes. The Separator dropdown lets you pick a hyphen, dot, underscore, space, or no separator at all. A hyphen or dot is usually easiest to type accurately on both desktop and mobile keyboards, while some login forms reject spaces in passwords.

Turn on 'Capitalize each word' if a site requires an uppercase character, and 'Append a number' if it requires a digit — many login forms enforce these composition rules even for long passphrases. Both options add negligible extra memorization effort while satisfying stricter password policies.

Use Passphrase mode with 7-8 words, a hyphen or dot separator for easy retyping, capitalize each word on, and append a number on — this comfortably clears 90+ bits of entropy while staying far easier to memorize and type accurately than an equivalent-strength random-character password.

The Length slider in Random characters mode runs from 8 up to 128 characters, matching the 'up to 128 characters' promise in the tool's title. For most logins 16-20 characters is plenty; push toward 128 only for systems that specifically call for an extremely long secret, like certain API tokens or hardware security modules.

The Words slider in Passphrase mode ranges from 3 words (shorter, lower entropy) to 12 words (extremely high entropy, well over 150 bits). The default of 6 words balances memorability with the EFF-recommended ~77-bit minimum for a strong passphrase.

The Regenerate button disables and the password field clears, with a hint reading 'Pick at least one character class to enable generation.' At least one of Uppercase, Lowercase, Numbers or Symbols must stay checked, since the generator needs a character pool to draw from.