I built this because most online password checkers send your password to their server for “analysis” — which defeats the entire purpose.

This one runs 100% client-side:

  • Zero network requests after page load
  • Entropy calculation based on character space
  • Crack time estimates for different scenarios
  • Common password detection (top 50 list)
  • No tracking, no analytics, no cookies

You can verify by opening DevTools → Network tab. Nothing is sent.

The source is right there in the page — View Source to see the entire thing.