Password Strength Calculator
Measure password entropy and estimated crack time.
Entropy
71 bits
Strong
Offline crack time (10B/sec)
5,115 years
Possible combinations
62^12
Assumes random characters. Real words, patterns, and reuse cut effective entropy drastically.
Length beats complexity
Entropy is length × log₂(alphabet), so length compounds where symbols only add: 16 lowercase letters (75 bits) beat 8 full-charset characters (52 bits). Four random common words — the passphrase pattern — reach ~77 bits and stay typeable.
The assumptions that matter
These times assume truly random characters and an offline attacker at 10 billion guesses per second. Human-chosen passwords fall to dictionary attacks far faster, and reused passwords fall instantly via breach lists — a password manager fixes both failure modes.
Frequently asked questions
- How does the Password Strength Calculator work?
- Measure password entropy and estimated crack time.
- Is the Password Strength Calculator free to use?
- Yes. The Password Strength Calculator is completely free, runs entirely in your browser, and requires no account or sign-up. Your inputs never leave your device.
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