Passphrase Generator
Several unrelated words picked at random are as strong as a random string and far easier to type from memory; this page builds them from the EFF word list.
Words are drawn from the 7,776-word EFF list, so each one adds 12.9 bits. Easier to type and remember than a random string of the same strength.
A PIN is only as safe as the device that rate-limits it. Do not reuse it as a password.
Generate a Random Word Passphrase
A passphrase is a password made of whole words instead of characters: tricycle-jigsaw-rehab-ointment-zoning rather than a string of punctuation. It is not weaker for being readable. Strength comes from how the words were chosen, and here each one is drawn at random from a list of 7,776 by the generator itself, not by you.
That distinction matters more than anything else on this page. A line of poetry, a song title or a sentence you thought of is not random however long it runs, because guessing programs feed on published text. Picking blindly from a fixed list is what makes the arithmetic below true.
The word list
The words come from the large passphrase list published by the Electronic Frontier Foundation, used here unchanged under the <abbr title="Creative Commons Attribution 3.0 United States">CC BY 3.0 US licence. It holds 7,776 entries of 3 to 9 letters, short enough to type and ordinary enough to spell from hearing them once. The count is deliberate: 7,776 is 6 to the fifth power, so the original method rolls five dice to find each word, which is where the name Diceware comes from.
Because every word is equally likely, each one contributes the base-2 logarithm of 7,776, or about 12.9 bits. The list is around 76 KB and is fetched only when you switch to Passphrase mode, so the rest of the tool stays light.
Why five or six words
| Words | Entropy | Equivalent random characters |
|---|---|---|
| 3 | about 39 bits | 6 |
| 4 | about 52 bits | 8 |
| 5 | about 65 bits | 10 |
| 6 | about 78 bits | 12 |
| 8 | about 103 bits | 16 |
| 12 | about 155 bits | 24 |
The right-hand column is the number of random characters from the generator's full 88-character pool that would give the same strength, and it works out at almost exactly two characters per word. Three or four words are too few for anything that matters: at 39 to 52 bits they are within reach of a serious offline attack on a leaked database. Five words puts you past that line, six words at roughly 78 bits is the usual advice for a secret that guards other secrets, and the slider goes to twelve if you want room to spare.
Easier to type where typing is hard
A random string of equal strength is shorter but hostile to type anywhere without a real keyboard. Ten characters of mixed punctuation on a phone means switching layouts twice per symbol, hunting for the right bracket and squinting at whether that is an l or a 1; the same job on a games console or a smart TV, letter by letter with a remote, is worse. A six-word passphrase is all lowercase letters and one repeated separator: long, but every keystroke is on the first keyboard layer, and you can read back where you are.
Pick the separator to suit the field. Hyphens and underscores are accepted almost everywhere; spaces read most naturally but some login forms trim or reject them, so try one before you commit. Capitalise each word and Add two digits exist for systems with rules about character classes rather than for strength.
Where a passphrase belongs
Use one for the handful of secrets you type from memory: the master password of your password manager, a disk encryption key, the login of the laptop itself. Every other account is better served by a long random string from the strong password generator, which a password manager fills in for you and nobody has to memorise. The guide to strong passwords covers the rest of the picture — managers, two-factor authentication and when a password is actually worth changing.
Two related shapes have their own pages: a random PIN for keypads and lock screens, and a Wi-Fi key for something that has to be typed once on every device in the house.