Password Strength Checker

Test how strong a password is in your browser with a live strength meter, entropy in bits, character-set analysis, and tips to make it stronger.

100% private. Your password is checked entirely in your browser and is never typed into a network request, logged, or sent anywhere.
Strength Waiting for input

Entropy and stats

Entropy
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Length
0
Character pool
0
Crack time estimate
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Character sets used

  • Lowercase (a-z) No
  • Uppercase (A-Z) No
  • Digits (0-9) No
  • Symbols (! @ # ...) No

The Password Strength Checker tells you in real time how strong a password is, with a clear strength meter, the estimated entropy in bits, a breakdown of the character types used, and concrete tips to improve it. Everything runs in your browser, so your password is never sent anywhere.

What is a password strength checker?

A password strength checker estimates how hard a password would be to guess or crack. This tool scores your password from Very Weak to Very Strong, calculates its entropy in bits from its length and the variety of characters it uses, flags common weaknesses, and suggests how to make it stronger. It works entirely on your device with no account and no network calls.

How to check your password strength

Type a password into the field and the results update instantly as you type.

  1. Type or paste the password you want to evaluate.
  2. Use the Show/Hide button if you want to read what you typed.
  3. Watch the strength meter, entropy, and character-set analysis update live.
  4. Read the weaknesses and suggestions, then adjust your password and watch the score improve.

How is password strength measured?

Strength here is based mainly on entropy, the number of bits of unpredictability in a password. Entropy grows with both length and the size of the character pool: using lowercase, uppercase, digits, and symbols enlarges that pool. The tool also penalizes known weak patterns such as very common passwords, single character classes, simple sequences, and long repeats, because those make a password far easier to guess than its raw length suggests.

Why use this password strength checker?

  • Completely private: your password is analyzed in your browser and never sent to a server.
  • Live strength meter with five levels from Very Weak to Very Strong.
  • Shows estimated entropy in bits and the size of the character pool.
  • Breaks down which character sets you used: lowercase, uppercase, digits, and symbols.
  • Detects common weaknesses like short length, common passwords, sequences, and repeats.
  • Gives clear, actionable suggestions to strengthen the password.

Frequently asked questions

Is it safe to type my password here?

Yes. The check runs entirely in your browser using JavaScript. Your password is never sent over the network, never stored, and never logged. You can confirm this by opening your browser's network tools and watching that nothing is sent as you type.

What does entropy in bits mean?

Entropy is a measure of how unpredictable a password is. It is calculated from the password length and the size of the character pool it draws from. Each extra bit roughly doubles the number of guesses needed, so more bits means a stronger password. As a rough guide, under 28 bits is very weak and 80 bits or more is very strong.

Why is my long password still rated weak?

Length helps, but predictable content hurts. A long password that is a common phrase, a single repeated character, or a keyboard pattern like qwerty or 1234 is easy to guess despite its length. This tool lowers the score for those patterns, which is why adding variety and avoiding common words matters.

Is the crack time estimate exact?

No. It is a rough illustration based on the size of the character pool and the password length, assuming a fast offline guessing attack. Real-world cracking speed depends on the attacker's hardware and how the password is stored. Treat the estimate as a relative guide, not a precise promise.

What makes a strong password?

Length is the single biggest factor, so aim for at least 12 to 16 characters. Mixing lowercase, uppercase, digits, and symbols helps, and avoiding common words, names, sequences, and repeats is essential. A passphrase made of several unrelated words is both long and easy to remember, which makes it a great choice.