Password Strength Checker
Test your password strength instantly. See crack time, get security tips, and check if it's been leaked. 100% private – works offline in your browser.
Password Checker
Privacy: All analysis happens locally in your browser. Nothing sent to servers.
How to Use Password Checker
- 1 Type or paste your password in the secure input field
- 2 See instant strength score (1-5) and crack time estimate
- 3 Review warnings about common patterns or leaked passwords
- 4 Follow personalized suggestions to improve security
- 5 Aim for "Strong" or "Very Strong" with 60+ bits entropy
What You Get
An advanced password analyzer that calculates entropy, detects keyboard patterns (qwerty), sequential characters (123abc), common passwords from leaked databases, and repeated characters. All processing happens 100% locally.
Input: password123
Output: Very Weak – common password, cracked instantly
Input: Tr0ub4dor&3
Output: Fair – 45 bits, cracked in months
Input: correct-horse-battery-staple
Output: Very Strong – 77 bits, centuries to crack
How do I check if my password is strong?
Type your password in the input field. See instant strength score (1-5), crack time estimate, and specific warnings about patterns or weaknesses.
Is my password sent to a server when I check it?
Never. All analysis happens 100% locally in your browser using JavaScript. Your password never leaves your device. Works offline.
How is password crack time calculated?
We assume 10 billion guesses per second (high-end GPU cluster). Real attacks vary - online attacks are slower, offline attacks on stolen hashes can be faster.
What makes a password strong?
Three factors: length (12+ characters), character variety (uppercase, lowercase, numbers, symbols), and randomness (no dictionary words or patterns). Length matters most.
Is a passphrase better than a complex password?
Yes. Passphrases like "correct-horse-battery-staple" are memorable and highly secure. A 4-word passphrase has about 44 bits of entropy.
Why is my complex password rated weak?
Common patterns like "P@ssw0rd!" or keyboard sequences like "qwerty" are in attacker dictionaries. Predictable substitutions (a→@, o→0) do not add real security.
How do I create a strong password I can remember?
Use a passphrase: 4-5 random words plus a number. Example: "purple-monkey-dishwasher-42". Or use a password manager for truly random passwords.
What password length is recommended?
12 characters minimum, 16+ recommended. For master passwords and critical accounts, use 20+ characters or a 5-word passphrase.
Related:
Your password is analyzed 100% locally in your browser. Nothing is ever sent to any server or stored anywhere. Works offline.