Calzivo

Local secure randomness

Password Generator

Generate a 12- to 128-character password locally with independently selected character classes and bias-free browser randomness.

Password settings

Enter a whole number from 12 to 128.

Character classes

Select at least one. Selection defines the possible alphabet, not a per-class guarantee.

Generated result

No password generated

Choose settings and generate explicitly. Settings never trigger automatic regeneration.

How selection works

Every position is selected independently from the complete enabled alphabet. Lowercase, uppercase, numbers, and the exact 29-symbol set are appended in that order when selected.

Rejection sampling discards random bytes outside an even mapping range, avoiding the modulo bias caused by mapping every byte directly.

Selected classes define possible characters; the generator does not force one character from each class and does not shuffle afterward.

Privacy and security context

Passwords are generated in this browser with cryptographically secure browser randomness and are not sent to a password-generation server by this tool.

Security also depends on length, uniqueness, storage, account protections, and the service using the password. Use a password manager and a unique password for each account.

Copying places the password in the device clipboard, which Calzivo does not control afterward.

Worked example and mistakes

Example: length 20 with all four classes samples 20 independent positions from the combined alphabet. A valid result might omit one selected class.

  • Reusing one password across accounts.
  • Assuming selected classes must all appear.
  • Leaving a copied password in clipboard history.
  • Saving generated passwords in unprotected notes.

FAQs and security sources

Does the tool rate the result? No. It does not assign a score or recommendation.

Can I use one class? Yes. Any one selected class is enough to define an alphabet.

Sources: Web Crypto, NIST SP 800-63B, and OWASP password guidance.