Kastavo

Password Generator

Choose the length and character types and see the generated password instantly — nothing ever leaves your browser.

Strength: Strong

Security tips

  • Use a different password for every important account.
  • Prefer 16 characters or more whenever the service allows it.
  • Combine uppercase, lowercase, numbers, and symbols.
  • Store your passwords in a password manager, not in plain text.

How it works

The password is generated locally in your browser using the Web Crypto API (crypto.getRandomValues), which provides cryptographically secure random numbers — far less predictable than Math.random(). No generated password is ever sent to a server: everything happens on your device. The estimated strength is calculated from the password's entropy (length × log2 of the chosen character set size): the more possible characters and the longer the password, the higher the entropy and the harder it is to guess by brute force.

Frequently asked questions

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