Password Strength Checker

What is the Password Strength Checker?

Check how strong a password is and how long it would take to brute-force. Checking a password’s strength estimates how long it would take to crack, and this checker runs entirely in your browser so nothing is sent anywhere.

How to use the Password Strength Checker

1. Enter your password.
2. Results update automatically as you type; you can also press Calculate.
3. Read the output: strength, entropy, brute-force time (10b guesses/s), tips.
4. Use the 📊 chart to see the result visually, then copy or share it.

Formula and method

Worked example

With password = Tr0ub4dor&3, the Password Strength Checker returns strength: Strong; entropy: 72 bits; brute-force time (10b guesses/s): 9,012.1 years.

Where the Password Strength Checker helps in real life

You want to know whether the password on an old email account is strong enough. The checker estimates crack time and points out weaknesses such as common words.

A trainer running a security workshop shows staff how much stronger a four-word passphrase is than a short password with symbols.

Common mistakes to avoid

• Typing live passwords into checkers on sites you do not trust.
• Using names, pets or birthdays that attackers can find online.
• Assuming one symbol makes a short password strong.
• Ignoring length, the biggest factor in strength.

💡 Practical tip: Length usually matters more than adding a single symbol or number.

Tips for better results

• Prefer long passphrases of several random words.
• Use a different password for every account.
• Change any password the checker rates as weak.

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