Password strength checker

Estimate password strength from length, character classes, and common patterns — locally.

This is an estimate assuming random characters — real attackers try words, leaked lists, and substitutions first. The password never leaves this browser.

How to use

  1. Type or paste a password.
  2. Run the check.
  3. Read the verdict, the entropy estimate, and the checklist.

What it supports

An estimate, not a guarantee — it assumes random characters, while real attacks try words, leaked lists, and substitutions first. Up to 512 characters; nothing is transmitted or stored.

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