Passphrase Generator
Generate memorable, high-entropy passphrases using the EFF Large Wordlist. Cryptographic random selection in your browser.
Wordlist: EFF Large Wordlist (7,776 words, CC-BY 3.0). Random selection uses crypto.getRandomValues with rejection sampling — no modulo bias.
About this tool
A passphrase is a sequence of common words separated by some delimiter, used in place of a traditional "complex" password. Five or six words pulled at random from a 7,776-word list give you 65 to 77 bits of entropy — equivalent to a 12 or 13-character fully-random ASCII password — but dramatically easier to remember, type, and dictate. That's the whole pitch.
The wordlist this tool uses is the EFF Large Wordlist, a 7,776-word curation by the Electronic Frontier Foundation specifically designed for passphrase use. The words are short (average 7 characters), acoustically distinct so you can dictate one over the phone without ambiguity, and exclude offensive or politically-charged terms. It replaced the original Diceware list in 2016.
Entropy math. With 7,776 words, each word contributes
log₂(7776) ≈ 12.92 bits. Six words gives ~77.5 bits;
seven gives ~90.4; eight gives ~103.4. For comparison, a typical
8-character password from a 95-character set has ~52 bits — and that
assumes every character is fully random, which they almost never are
in practice. NIST SP 800-63B's modern guidance (2017+) explicitly
recommends passphrases over forced-complexity short passwords.
Random selection. Word selection uses
crypto.getRandomValues, the cryptographic random source
built into your browser. To eliminate modulo bias — the
subtle non-uniformity you get when you naively do random()
% 7776 on a 32-bit integer — we use rejection sampling: any
raw 32-bit value at or above the largest multiple of 7,776 below
2³² is rejected and re-rolled. The cost is a fraction of a percent
extra computation for a perfectly uniform distribution.
Where the passphrases go. Generated passphrases exist only in your browser tab's memory. They are not sent to any server, written to localStorage, persisted to the URL hash, or logged anywhere. Close the tab and they are gone. The URL hash records your option settings (word count, separator choice, capitalize toggle) so you can bookmark a configuration — but the passphrases themselves are regenerated fresh each time you load the page.
Frequently asked questions
How is this different from a random password generator?
Passphrases trade a smaller character set for memorability. A six-word EFF-wordlist passphrase has ~77 bits of entropy — equivalent to a 13-character random password — but is dramatically easier to remember and type. Industry guidance (NIST SP 800-63B) explicitly endorses passphrases over forced-complexity passwords.
How many words do I need?
For most accounts, 6 words (~77 bits) is overkill against online attackers throttled to a few guesses per second. For high-value targets like a master password, 7 (~90 bits) or 8 (~103 bits) is recommended. Each additional word multiplies the search space by 7,776.
Where does the wordlist come from?
It is the EFF Large Wordlist — 7,776 words selected by the Electronic Frontier Foundation specifically for passphrase use. Words are short (avg 7 characters), distinct (no near-duplicates that could be misheard or mistyped), and exclude offensive terms. Released under CC-BY 3.0.
Is the random selection actually random?
Yes. Selection uses crypto.getRandomValues — the cryptographic random source built into your browser by Chromium / Firefox / Safari engineers. We use rejection sampling against the largest multiple of 7,776 below 2^32 to eliminate modulo bias. Each word is independently uniform over the 7,776-word space.
Should I add the digit and symbol?
Only if a site requires them. They add minimal entropy (~7 bits combined) but increase memorability friction. The passphrase itself is what does the work. Some legacy systems still enforce "must contain a number and a symbol" — toggle these for those.
Are the generated passphrases stored anywhere?
No. They exist only in your browser tab's memory until you close it. The URL hash records your option settings (count, separator, etc.) so you can bookmark a configuration — but never the passphrases themselves.