Free online password generator
Create strong passwords in seconds

A brute-force attack tries every possible character combination one by one — the longer and more random the password, the longer this takes. A dictionary attack tries common passwords and their variants (e.g. "password123"). Credential stuffing reuses data from earlier breaches — if you reuse the same password in multiple places, one compromised account makes the others easier to breach too. Phishing, on the other hand, doesn’t break the password technically — it tricks you into handing it over on a fake site.

Entropy is a measure of a password’s unpredictability, expressed in bits — the higher it is, the more attempts a brute-force attack needs. It depends on the password’s length and the number of possible characters at each position. Adding a single character increases the number of possible combinations exponentially, which is why length matters more for security than complexity rules alone. Passly.pl shows the entropy of every generated password in bits.

The US institute NIST (Special Publication 800-63B) moved away from forcing frequent password changes and rigid complexity rules, since those practices often led to weaker, predictable passwords (e.g. "Password1!" → "Password2!"). Instead it recommends long passwords or passphrases, checking them against known-breach databases, and changing a password only when compromise is suspected.

2FA (or MFA — multi-factor authentication) requires a second element to confirm your identity besides the password: a code from an authenticator app, a hardware key (e.g. a YubiKey), or a biometric fingerprint. Even if your password leaks, an attacker without the second factor can’t log in. It’s a single change that most effectively limits the damage of a leaked password.

Passkeys are a sign-in standard based on public-key cryptography (FIDO2/WebAuthn) — instead of a password, your device holds a private key, and the server only knows the public key, which can’t be used to sign in without the device. This eliminates phishing and password leaks at the source. More and more services support passkeys, but passwords will remain common for years to come — which is why a strong password generator still matters.