🎲 Passphrase Generator (Diceware)
Generate a strong, memorable passphrase, random words from the EFF diceware list, with a live entropy readout. Easier to remember than a random password, and often stronger.
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True diceware: each word is chosen from the 7,776-word EFF list with crypto.getRandomValues (rejection-sampled, so every word is equally likely). Each word adds ~12.9 bits of entropy, a memorable 6-word passphrase is stronger than most random passwords. 🔒 Generated entirely in your browser.
How the passphrase generator (diceware) works
This is true diceware: each word is chosen from the 7,776-word EFF long list using crypto.getRandomValues with rejection sampling, so every word is equally likely. Each word adds about 12.9 bits of entropy, so a six-word passphrase carries roughly 77 bits, stronger than most people’s random passwords, yet far easier to remember. Choose the word count and separator, and optionally capitalise words or append a number.
Memorable and strong is not a contradiction. A passphrase like “correct-horse-battery-staple-anchor-mango” is trivial to remember and brutal to brute-force. The entropy readout shows exactly how strong it is, honestly, from the word count, not a hand-wavy “strength meter”.
Frequently asked questions
What is diceware?
A method of building passphrases by choosing random words from a fixed list. Each word from the 7,776-word EFF list adds log₂(7776) ≈ 12.9 bits of entropy, so the strength is exactly the word count times 12.9 bits.
How many words should I use?
Six words (~77 bits) is a strong, practical default for important accounts. Use seven or more (~90+ bits) for high-value secrets like a password-manager master password.
Is a passphrase really stronger than a password?
Often, yes, and it’s far easier to remember. A six-word passphrase’s ~77 bits exceeds a typical 10-character random password, and you can actually recall it.
Is the randomness secure?
Yes, words are selected with crypto.getRandomValues and rejection sampling, so the choice is cryptographically random and unbiased. No pseudo-random Math.random is used.
Should I add a number or capital letters?
They can satisfy fussy password rules, but the real strength comes from the number of random words. Adding a word raises entropy far more than adding a digit.
Is the passphrase generated privately?
Yes, the word list and the generation both run in your browser; no passphrase is ever sent to a server.
How is the entropy figure calculated?
It is the word count times log₂(7776), the number of choices per word. log₂(7776) ≈ 12.9 bits, so a five-word passphrase is about 64 bits, six words about 77 bits, and seven words about 90 bits. Because each word is chosen independently and uniformly, the bits simply add up.
Does it matter that the words are common and in a public list?
No, the security comes from the number of equally-likely combinations, not from the words being secret. An attacker who knows you used the EFF list still faces 7,776 possibilities per word, which is exactly what the entropy figure counts. Secrecy of the method adds nothing; length does.
Why use words instead of random characters?
Human memory handles a short sequence of real words far better than an equally strong string of random symbols, and a six-word passphrase already out-scores a typical random password on entropy. You get strength and recall at once, which is the whole appeal of diceware.
Is the passphrase generated privately?
Yes, the word list and the generation both run in your browser; no passphrase is ever sent to a server.