What makes a password strong?

A strong password has length (12+ characters), mix of uppercase/lowercase/numbers/symbols, no dictionary words, and no patterns like keyboard sequences or repeated characters.

What is password entropy?

Entropy measures unpredictability in bits. Each bit doubles the number of attempts needed. 80+ bits is considered strong against offline attacks.

Is 2FA necessary if I have a strong password?

Yes. Two-factor authentication adds a second layer of protection. Even if your password is compromised, the attacker still needs the second factor.

Should I use a password manager?

Yes. Password managers generate and store complex unique passwords for each service, eliminating password reuse and making phishing harder.

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Password Strength Checker

Analyze your password strength with detailed breakdowns, crack time estimates, and actionable improvement suggestions.

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Enter a password to analyze its strength.

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Frequently Asked Questions

What makes a password strong?: A strong password has length (12+ characters), mix of uppercase/lowercase/numbers/symbols, no dictionary words, and no patterns like keyboard sequences or repeated characters.
What is password entropy?: Entropy measures unpredictability in bits. Each bit doubles the number of attempts needed. 80+ bits is considered strong against offline attacks.
Is 2FA necessary if I have a strong password?: Yes. Two-factor authentication adds a second layer of protection. Even if your password is compromised, the attacker still needs the second factor.
Should I use a password manager?: Yes. Password managers generate and store complex unique passwords for each service, eliminating password reuse and making phishing harder.
What are the current NIST password guidelines?: NIST SP 800-63B recommends minimum 8 characters, checking against breached passwords, no composition rules (uppercase/number/symbol requirements), and allowing all ASCII characters plus spaces.
What is a passphrase?: A passphrase is a sequence of random words (e.g., "correct horse battery staple"). It is easier to remember than random characters while offering high entropy.
Can biometrics replace passwords?: Biometrics are convenient but not secrets — they cannot be changed if compromised. Use biometrics as a factor alongside a password, not as a replacement.
How does brute force work?: Brute force tries every possible character combination. Rate limiting and account lockouts mitigate online brute force. Offline attacks (stolen hashes) need high entropy passwords.
What is social engineering?: Social engineering tricks people into revealing passwords through phishing emails, fake login pages, or phone calls. Technical controls cannot fully prevent it.
How often should I change my password?: NIST no longer recommends periodic changes. Change passwords only when you suspect compromise. Frequent changes lead to weaker, predictable passwords.
What is credential stuffing?: Credential stuffing uses leaked username/password pairs from one breach to access accounts on other services. Unique passwords per service prevent this.
What are rainbow tables?: Rainbow tables are precomputed hash-to-password mappings. Salting hashes (adding random data per password) makes rainbow tables ineffective.
Is a password with symbols always strong?: No. "Password1!" is weak despite having uppercase, lowercase, digit, and symbol. Length and unpredictability matter more than character variety alone.
What is the best way to store passwords?: Use a password manager (Bitwarden, 1Password, KeePass). For developers: hash passwords with Argon2id or bcrypt, never store plaintext or unsalted hashes.