💪 Password Strength Checker
Instantly analyze any password's strength, entropy, and estimated crack time. Your password never leaves your device.
Enter a password above to see its strength analysis
How this checker scores a password
The score is based on entropy — the number of bits of randomness in the password — calculated from its length and which character types it uses (lowercase, uppercase, numbers, symbols). A longer password with a wider mix of character types has more possible combinations, so it takes an attacker proportionally longer to guess by brute force. The checker also flags obvious weaknesses like repeated characters or common patterns such as "123" or "qwerty", which real-world crackers try first regardless of length.
Everything happens locally in your browser using JavaScript — the password you type is never sent to a server, logged, or stored anywhere, so it's safe to test a password you actually use. If the result comes back weak, the password generator can create a stronger replacement instantly.
Further reading: How password crackers actually work