Why words work
Human memory is bad at kQ9#vT2!zL and good at stories. Five unrelated words are easy to picture as one absurd scene, and the entropy math does not care that they are pronounceable: what matters is that each word was chosen uniformly from a known list. 1,316 words means 10.4 bits per word whether the word is "umbrella" or "cat". The table below is computed by this site's engine from the actual list size.
| Words | Entropy | Entropy with random digit | Roughly equivalent to |
|---|---|---|---|
| 3 words | 31.1 bits | 34.4 bits | 5 characters from the full 94-char set |
| 4 words | 41.4 bits | 44.8 bits | 6 characters from the full 94-char set |
| 5 words | 51.8 bits | 55.1 bits | 8 characters from the full 94-char set |
| 6 words | 62.2 bits | 65.5 bits | 9 characters from the full 94-char set |
| 7 words | 72.5 bits | 75.9 bits | 11 characters from the full 94-char set |
| 8 words | 82.9 bits | 86.2 bits | 13 characters from the full 94-char set |
Two honest caveats. First, capitalization and separators are formatting: an attacker who knows you capitalize each word loses nothing, so they add no bits, and this page does not pretend otherwise. The optional digit is different — it is chosen uniformly, so it honestly adds log2(10) ≈ 3.3 bits, and it is counted. Second, the words must be random. A phrase you invent ("ilovemydog") is drawn from the tiny space of phrases humans invent, not from 1,3165 combinations; cracking tools carry dictionaries of exactly those. Generate, don't compose.
The word list itself is a self-built list of common English words — animals, foods, household objects, everyday verbs and adjectives — written for this site. It is smaller than the 7,776-word lists used by classic diceware-style systems, which is exactly why the entropy per word here is 10.4 bits rather than 12.9, and why the counts above are printed from the real list size instead of borrowed from a bigger one.
FAQ
How many words do I need?
Five words (≈51.8 bits) is a sound minimum for a password manager's master password. Use six or more for anything protecting high-value accounts without two-factor authentication.
Is a passphrase better than a random password?
Per character, no — a random character carries more entropy. Per thing a human can memorize and type, yes. The comparison page lays out both sides.
Can I use this as my master password?
Yes — that is its best use. Generate it here, write it down on paper kept somewhere safe while you memorize it, and store it in your manager like everything else.
Does the site keep my passphrase?
No. It is generated in this tab and never transmitted. See the privacy page.