Passphrase Generator

Seed

The same seed rebuilds the same phrase, so use a private one.

How many words

Separator

Capitalise words

Add a number

Result

Passphrasecinema-belt-brick-alert-cotton-15
Entropy, bits45.2
Brute force timeabout 33 minutes of brute force
Length, characters33
Words in the list209
What mattersThe list holds 209 words, so each one adds 7.7 bits, and the time assumes ten billion guesses a second — a GPU rig against a fast hash. A full 7,776-word diceware list gives 12.9 bits a word.

Length beats punctuation

Builds a password out of random words and states its entropy in bits and how long brute force would take.

A password made of four random words is easier to remember and harder to guess than one made of a short word with a digit and an exclamation mark glued on. Attackers know every substitution people make; they cannot know which words came up.

What matters is the number of choices, not the number of characters. Each word drawn from a list of N adds log2(N) bits, and that figure is shown so you can judge the phrase rather than trust it.

What this calculator shows

The passphrase with your separator and options
The entropy in bits and the size of the word list
How long brute force would take at ten billion guesses a second

What to keep in mind

Entropy counts only the choices actually made. Adding characters that were not chosen randomly adds length, not strength.
The crack time assumes a fast hash on GPUs. A password stored with bcrypt or argon2 takes a million times longer to attack.

FAQs

How many words are enough?

Six from this list gives 54 bits, which is reasonable. From a full diceware list of 7,776 words, five words already give 64 bits.

What is entropy in bits?

The base-two logarithm of the number of equally likely possibilities. Each extra bit doubles the work an attacker has to do.

Does capitalising the first letter help?

Barely. If the rule is predictable — and capitalising every word is predictable — it adds almost nothing. A random extra word adds far more.

Is it safe to generate a password in a browser?

The phrase never leaves your device here, but the seed reproduces it exactly. For anything important, change the seed to something private and store the result in a password manager.

Worked example

Five words and a number

Input: seed "unitools", 5 words, hyphen separator, a number on the end

Output: cinema-belt-brick-alert-cotton-15

Note: That is 45 bits. It is fine for an account with rate limiting behind it and weak against an offline attack on a leaked fast-hash database — which is exactly why the number is shown rather than a green tick.

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Result

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