Password Strength Checker

An instant verdict and an entropy estimate — checked on your device only.

FREE TOOL · 100% PRIVATE · NO SIGN-UP

🔒 Private by design: your password never leaves this page. There is no server — nothing you type is sent anywhere, uploaded, saved or tracked.

Verdict (estimate)
—
Entropy estimate
—
Characters
0
Character set size
—
Checklist passed
0 / 7

Start typing — the strength estimate updates live, right here in your browser.

✅ Strength Checklist

🛠️ How to Use This Password Strength Checker

  1. 1.Type or paste a password. The verdict, meter and entropy estimate update on every keystroke — nothing is submitted anywhere.
  2. 2.Read the verdict. It runs from Very weak to Very strong and is based on estimated entropy in bits, with penalties for common words, sequences and repeats.
  3. 3.Work through the checklist. Each green tick is one more thing an attacker has to get through — length matters most.
  4. 4.Follow the tips. The note under the meter points at the weakest part of your current password and how to fix it.
  5. 5.Close the page. Your password was never stored or sent, so there is nothing to delete — it is simply gone.

❓ FAQ

How is password strength calculated?

With a simple, transparent estimate: your password's length multiplied by log2 of its character-set size (26 for lowercase, plus 26 for uppercase, 10 for digits, 32 for symbols), minus penalties for common words, sequences like 1234 and repeated characters. It is a guide, not a guarantee — no checker can prove a password is safe.

Is my password sent to a server?

No — never. This page has no server and makes no network requests. The password you type is checked by JavaScript running in your own browser tab, and it disappears the moment you close the page. Nothing is uploaded, saved or tracked.

What makes a password strong?

Length first: a passphrase of four or five random words is stronger than a short string of symbols, and far easier to remember. Use a different password for every account, and let a password manager remember them so you only need one strong master password.

Is this password strength checker free?

Yes — 100% free, no sign-up, and it works offline once the page has loaded, because everything happens on your own device.

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