Free password strength checker. Scores your password in real time, estimates crack time and flags weaknesses. 100% in-browser — your password never leaves.
Weak passwords are the #1 cause of security breaches. This tool analyzes your password strength in real-time without sending it anywhere—all checking happens in your browser.
Use at least 16 characters, avoid personal information, and never reuse passwords across sites.
The National Institute of Standards and Technology (NIST) updated their password guidelines in Special Publication 800-63B. These recommendations have shifted the industry away from outdated practices.
✅ Length over complexity - Minimum 8 characters, but 15+ characters strongly preferred. Long passphrases like "correct-horse-battery-staple" are more secure than short complex passwords.
✅ Check against compromised passwords - Verify new passwords against databases of known breached passwords (like Have I Been Pwned).
✅ Allow all characters - Support spaces, emojis, and Unicode. Don't restrict character sets unnecessarily.
✅ Use password managers - Enable paste functionality so users can use password managers effectively.
❌ Forced rotation - Changing passwords every 90 days leads to weaker passwords. Only require changes after a breach.
❌ Composition rules - Requirements like "must contain uppercase, number, and symbol" don't improve security significantly.
❌ Password hints - Security questions and hints often weaken security.
❌ SMS-based 2FA - SIM swapping attacks make SMS codes vulnerable. Prefer authenticator apps or hardware keys.
| Factor | Impact |
|---|---|
| Length | Highest impact - exponentially increases attack time |
| Randomness | High impact - prevents dictionary attacks |
| Uniqueness | Critical - prevents credential stuffing |
| Breach status | Critical - known passwords are instantly cracked |
A 20-character passphrase with common words beats an 8-character complex password. Focus on length, uniqueness, and breach checking.
Strong passwords have: 16+ characters (longer = stronger), mix of uppercase, lowercase, numbers, symbols, no dictionary words or personal info, no patterns (123, abc), unique per account. Example: "Tr0pic@l-Sunset#47$Moon". Use passphrases: "Coffee!Mountain$River29". Entropy >60 bits ideal. Avoid: password123, qwerty, 12345678. Use password manager to generate and store unique passwords for every account.
Entropy measures password unpredictability in bits. Higher = stronger. Calculation: bits = log2(possible_combinations). Example: 8 lowercase letters = 37 bits (weak), 16 mixed characters = 95 bits (strong). 60+ bits = resistant to offline attacks, 80+ bits = excellent. Character variety matters: adding numbers/symbols increases entropy exponentially. Use entropy to compare password strength objectively.
Depends on: password length, character variety, attacker resources. Online attacks (slow): 1000 tries/sec - weak passwords cracked in seconds. Offline attacks (fast): 100 billion tries/sec (GPUs) - 8 char password cracked in hours. Quantum computers (future threat). Defense: 16+ character passwords take centuries to crack offline. Use multi-factor authentication (MFA) - even cracked password cannot access account alone.
Yes, but length matters more. Special characters increase entropy slightly. 16 character lowercase > 10 character with symbols. Best: combine both. Use special characters naturally: "Blue$Sky&Morning27" vs "p@ssw0rd" (weak despite symbols). Avoid predictable substitutions (@ for a, 0 for o). Focus on length first, variety second. Passphrases with spaces/punctuation are ideal.
Check using Have I Been Pwned (HIBP) Pwned Passwords database (850M+ breached passwords). HIBP uses k-anonymity - sends only first 5 hash characters, checks locally. Our tool integrates HIBP API. If found: change immediately, enable MFA, check for unauthorized access. Breached passwords are targeted in credential stuffing attacks. Never reuse passwords across accounts.
Yes. Password managers are safer than reusing weak passwords. They generate strong unique passwords, store encrypted (AES-256), sync across devices, auto-fill securely. Recommended: Bitwarden (open-source), 1Password, LastPass, Dashlane. Use strong master password + MFA. Risk: single point of failure if master password compromised. Benefit: eliminates password reuse, phishing-resistant, convenience. Essential security tool.
Common mistakes: using personal info (names, birthdays), dictionary words (password, admin), patterns (123456, qwerty), password reuse across accounts, short passwords (<12 chars), predictable substitutions (p@ssw0rd), writing passwords down insecurely, sharing passwords, no MFA. Attackers exploit these patterns. Solution: password manager + unique passwords + MFA for all accounts. Change default passwords immediately.
Change only when: confirmed breach, suspected compromise, sharing password (stop sharing), weak password needs upgrade. Do not change routinely (causes weaker passwords). NIST (2024) recommends: no mandatory periodic changes, change only after breach, use long unique passwords + MFA. Exception: rotate privileged access credentials (90 days). Focus on breach monitoring, not arbitrary schedules.