What is a diceware-style passphrase?

It's a passphrase built from several random, unrelated words rather than a single mangled word — for example "Crane-Bicycle-Aware-42" instead of "P@ssw0rd!". Because each word is picked independently from a word list, the total randomness (entropy) is easy to calculate and can be made very strong just by adding more words.

How is the entropy in bits calculated?

Each word contributes log2(word list size) bits of entropy, multiplied by the number of words, plus log2(100) ≈ 6.6 bits if you include a random 2-digit number. More bits means more possible combinations an attacker would have to try.

How many words should I use?

Five or more words from a reasonably sized list generally gives strong entropy for most purposes. For highly sensitive accounts, use more words or pair the passphrase with two-factor authentication.

Is the word list or passphrase sent anywhere?

No. The word list is built into this page and the passphrase is generated locally in your browser using JavaScript's random number generator — nothing is transmitted or logged.

PASSPHRASE GENERATOR

Generate a memorable, diceware-style passphrase from a built-in word list, with an estimated entropy. Nothing leaves your browser.

Passphrase

Amused-Blouse-Card-Cause-Card-62

~49.9 bits of entropy

Word count: 5

Separator

Capitalization

Include a random number

How to generate a passphrase

1
Drag the word count slider to choose how many words your passphrase should have.
2
Pick a separator, capitalization style, and whether to append a random number.
3
Copy the passphrase, or hit Regenerate for a new one — the estimated entropy updates as you adjust settings.

Questions

What is a diceware-style passphrase?: It's a passphrase built from several random, unrelated words rather than a single mangled word — for example "Crane-Bicycle-Aware-42" instead of "P@ssw0rd!". Because each word is picked independently from a word list, the total randomness (entropy) is easy to calculate and can be made very strong just by adding more words.
How is the entropy in bits calculated?: Each word contributes log2(word list size) bits of entropy, multiplied by the number of words, plus log2(100) ≈ 6.6 bits if you include a random 2-digit number. More bits means more possible combinations an attacker would have to try.
How many words should I use?: Five or more words from a reasonably sized list generally gives strong entropy for most purposes. For highly sensitive accounts, use more words or pair the passphrase with two-factor authentication.
Is the word list or passphrase sent anywhere?: No. The word list is built into this page and the passphrase is generated locally in your browser using JavaScript's random number generator — nothing is transmitted or logged.