A strong password is long (12+ characters), uses a mix of character types (uppercase, lowercase, digits, symbols), and avoids predictable patterns like dictionary words, keyboard sequences, or personal info. Our checker evaluates all these factors in real-time.

Entropy measures randomness in bits. Higher entropy = harder to guess. A password with 60+ bits of entropy is considered strong. Entropy depends on length and character pool size. For example, a 12-character password using 70 possible symbols has ~74 bits of entropy.

We calculate the total possible combinations (character_pool^length) and divide by attack speeds. The estimate uses three scenarios: online attack (1,000 guesses/sec), fast GPU (1 billion/sec), and a large cluster (1 trillion/sec). Actual crack times depend on the hashing algorithm used by the service storing your password.

NIST SP 800-63B is a U.S. federal standard for digital identity. Key recommendations: minimum 8 characters, allow all printable ASCII characters including spaces, no mandatory composition rules (no forced special chars), and check passwords against known compromised lists. It prioritizes length over complexity.

PCI DSS (Payment Card Industry Data Security Standard) requires: minimum 7 characters, must contain both letters and numbers, and passwords must be changed every 90 days. Our tool checks the structural requirements but cannot enforce rotation policies.

No. All checks run entirely in your browser using JavaScript. Your password never leaves your device, is not stored, logged, or transmitted. You can disconnect from the internet and the tool will still work perfectly. This is a core privacy principle of our tool.

Attackers use dictionary attacks and pattern-based cracking before brute-forcing. Passwords like "Password123!" or "Summer2024" are cracked instantly despite meeting technical complexity rules. Our checker flags keyboard sequences, repeated characters, and common weak passwords.

Try the passphrase method: combine 4-6 random words like "correct-horse-battery-staple". Add a few numbers and symbols for extra strength. Alternatively, use a password manager to generate and store unique strong passwords for each account. Our built-in generator can create secure passwords instantly.