This passphrase generator builds phrases from the EFF wordlist, entirely in your browser. Six words is the usual choice, and the entropy readout updates as you change the settings.
What is a passphrase?
A passphrase is several random words joined together, chosen from a fixed list. Its strength comes from how many words were picked and how large the list was — not from mixing in symbols or swapping letters for digits.
Passphrase vs password
A random password packs entropy into few characters. A passphrase generator spreads the same entropy across more characters that happen to be pronounceable.
A comparison of entropy between passphrases from the EFF wordlist and fully random passwords. Three words gives about 39 bits, four gives 52, five gives 65, six gives 78, and eight gives 103. Six words is worth roughly the same as a twelve-character random password, at 77.5 bits against 78.8, but a passphrase can be retyped from memory.
Neither is stronger per character. The passphrase wins only where a human has to reproduce it from memory, which is a small but important set of cases.
Where Diceware came from
Arnold Reinhold proposed the method in 1995: roll five dice, read the resulting number off a word list, repeat. The first passphrase generator was a pair of hands and a pencil.
The EFF published its own lists in 2016, keeping the five-dice structure but choosing words that are easier to spell and harder to mistake for one another.
How many words do you need?
The arithmetic
Each word a passphrase generator picks contributes log₂(7776), which is 12.925 bits. The words are independent, so the total is that figure multiplied by the word count.
Three words is 39 bits, which a determined attacker cracks. Six words is 78, which nobody cracks. The passphrase generator shows the running total so the choice is not guesswork.
Six words is the usual answer
Six words is what EFF recommends for most uses, and it is where this passphrase generator opens. It puts you past the point where brute force stops being the weak link.
Going to seven or eight costs you very little effort and buys real margin if the phrase protects a password manager or an encrypted disk.
When three or four words is not enough
Four words is around 52 bits. That withstands online guessing, where a server rate-limits attempts, but not an offline attack against a leaked hash.
Set the passphrase generator low only where the value at risk is low. If you cannot say what happens when the account falls, treat it as important and use six.
How this passphrase generator works
The EFF wordlist
This passphrase generator draws from 7,776 English words, filtered by EFF to remove ones that are hard to spell, easy to confuse, or unpleasant to see on screen.
It is embedded in the page rather than fetched, so this passphrase generator never contacts a server for words — or for anything else.
Why 7,776 words
7,776 is 6⁵, which means one word per roll of five dice. That is the whole point of the number: the list works with physical dice as well as withcrypto.getRandomValues().
A convenient side effect is that each word carries exactly 12.925 bits, making the entropy arithmetic something you can check on paper.
The hyphen problem
Four entries in the list already contain a hyphen: drop-down,felt-tip, t-shirt and yo-yo.
The EFF wordlist contains four hyphenated entries: drop-down, felt-tip, t-shirt and yo-yo. When the passphrase separator is also a hyphen, a phrase such as t-shirt-abacus-zoom cannot be read unambiguously — it could be three words or four. This generator removes those four words when a hyphen separator is chosen, reducing the pool from 7776 to 7772 words, and lowers the reported entropy to match.
When you pick the hyphen separator, those four are excluded so the phrase can always be split back into words. The pool drops to 7,772 and the entropy readout drops with it.
The difference is around a thousandth of a bit. Reporting the number we did not actually use would be a larger problem than the number itself.
Making one you will actually remember
Separators and capitalisation
Hyphens survive nearly every form field and are easy to type, which is why the passphrase generator defaults to them. Spaces read more naturally but some systems still reject them.
Capitalisation adds almost no entropy, because the pattern is predictable. Use it when a site demands an uppercase letter, not as a security measure.
Adding a number or symbol
The passphrase generator can append one of each, and places them on a randomly chosen word rather than always the last. Cracking rules try the end of the string first.
Neither is counted in the entropy figure. Adding exactly one digit somewhere is itself predictable, so claiming credit for it would overstate the result.
What not to do
Do not run the passphrase generator repeatedly until you get words you like. Every rejection narrows the space toward phrases you find memorable, which is the same weakness as inventing one yourself.
Do not substitute letters for digits either. Turning horse intoh0rse is the first transformation any cracking tool applies.
Where passphrases fit
Master passwords and disk encryption
These are the cases a passphrase generator exists for: a small number of secrets you must type from memory, with nothing able to autofill them.
Accounts you type by hand
A television, a games console, a server console. Typing sixteen random characters on a remote control is miserable; typing six words from a passphrase generator is tolerable.
When a random password is the better choice
For everything your password manager fills in, use the password generator instead. There is no benefit to readability when no human ever reads it, and a shorter random string is easier to paste into a constrained field.
If you want something between the two — readable but shorter than a full phrase — the memorable password generator covers that ground.
Frequently asked questions
How many words should a passphrase have?
Six is the usual answer and what EFF recommends. Six words from the EFF list carry about 78 bits, which is beyond brute force. Four words is around 52 bits — fine for a low-value account, not for anything important.
Is a passphrase really as strong as a random password?
Six words is worth roughly the same as twelve fully random characters. The difference is that you can retype a passphrase from memory, which matters for the handful of passwords a manager cannot fill in for you.
Does this passphrase generator send anything to a server?
No. The wordlist is built into the page and words are chosen with the Web Crypto API in your browser. Load the page once and it keeps working with the network disconnected.
Which wordlist does it use?
The EFF long wordlist: 7,776 English words chosen to be easy to spell and hard to confuse with each other. It is published by the Electronic Frontier Foundation under a CC BY 4.0 licence.
Why 7,776 words?
It is six to the fifth power, so each word maps to one roll of five dice. That is what makes the list usable with physical dice, and it gives exactly 12.925 bits per word.
Should I add a number or a symbol?
Only if a site forces you to. It adds very little entropy and makes the phrase harder to type. Adding one more word does far more for strength than any punctuation.
Can I swap out a word I do not like?
Regenerate instead. Replacing words you dislike biases the result toward words you find memorable, which is exactly the predictability a passphrase generator exists to remove.
When should I use a passphrase instead of a password?
Anywhere you have to type it from memory: a password manager’s master password, disk encryption, a device login. For everything a manager fills in for you, a random password is the better fit.
More free generators
Every generator here runs locally in your browser, with no account and no limits. To check a phrase you already use, try the password strength checker.
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Methodology
Last updated
How entropy is calculated
entropy = words × log₂(pool size)
The pool is 7,776 words, or 7,772 when a hyphen separator forces the four hyphenated words out. An appended digit or symbol is deliberately not counted: adding exactly one of each is a predictable pattern, so including it would overstate the result.
Which wordlist, and where it comes from
The EFF long wordlist, 7,776 words, embedded at build time. PRD requirements for this site forbid fetching a wordlist from a third-party API, and embedding it is also what lets the page work offline.
The list is published by the Electronic Frontier Foundation underCC BY 4.0. It is used unmodified and attributed below.
How words are chosen
Each word is selected with crypto.getRandomValues() through rejection sampling, so all 7,776 entries are equally likely. Math.random() is never used. Words can repeat within a phrase, which is correct: excluding repeats would reduce the entropy rather than increase it.