Wordlist-based entropy
Passphrase Entropy Calculator
Calculate the entropy ceiling of randomly selected words and analyze a written passphrase without pretending every phrase is uniformly random.
Passphrase assumptions
Passwords are generated and evaluated locally in your browser using crypto.getRandomValues(). PwdGen does not upload or store generated values, and never includes password input in analytics. Strength and crack-time results are estimates, not guarantees.
Entropy result
Set a word count and wordlist size- Theoretical random-word entropy
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- Pattern-based estimate
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Random selection versus written phrases
A random passphrase has an entropy ceiling of W × log2(D), where W is the number of independently selected words and D is the wordlist size.
A phrase written by a person is not uniformly random. If you enter one, the local pattern checker estimates guesses from words, sequences, and common structure instead of applying the theoretical formula.
Passphrase Entropy Calculator FAQ
How large should the wordlist be?
Diceware-style lists commonly contain thousands of distinct words. The exact size must match the list used for random selection.
Are four random words enough?
It depends on the wordlist size, attack scenario, and account controls. Add more independently selected words when higher resistance is needed.
Does punctuation automatically make a passphrase strong?
No. Predictable punctuation adds little if the words and structure are familiar.