Passphrase Generator
Updated Free mock REST & WebSocket APIs
Create a random passphrase of short, common words — easy to remember and type, hard to crack. Pick the number of words, a separator and whether to add capitals and a digit.
Word list: 1,790 short common words · 10.81 bits per word
| Online login, rate-limited · 10 guesses/s | 1 billion years |
| Offline, slow hash (bcrypt) on a GPU rig · 100k guesses/s | 145,579 years |
| Offline, fast hash (MD5/SHA-1) on a GPU cluster · 100 billion guesses/s | 53 days |
Generate many at once
🔒 Generated on your device with crypto.getRandomValues. Nothing is sent, logged or stored.
How to create a passphrase
- Choose how many words — 5 or more for important accounts, 6 or 7 for a password-manager master password.
- Pick a separator and whether to capitalize words or add a digit (handy for sites with composition rules).
- Copy it, or press New until you get one you like — then memorize it by typing it a few times.
How strong is a passphrase?
Each word is chosen at random from 1,790 words, adding log₂(1,790) ≈ 10.8 bits. Adding one random digit to a random word adds log₂(10 × words) more bits. Capitalizing every word adds nothing — an attacker knows the pattern.
| Words | Entropy | Average crack time at 100 billion guesses/s |
|---|---|---|
| 4 | 43.2 bits | ~1 minute |
| 5 | 54.0 bits | ~1 day |
| 6 | 64.8 bits | ~5 years |
| 7 | 75.6 bits | ~9,000 years |
That last column assumes a fast, unsalted hash. Real services that store passwords with bcrypt, scrypt or Argon2 slow attackers by a factor of a million or more, so 5 words is plenty for most logins — and 6–7 is a comfortable choice for a master password.
The rule that matters: let the computer choose
The strength comes entirely from random selection. A phrase you invent (“ilovemydog2024”) or a famous quote is in every attacker's dictionary, no matter how long it is. Don't reroll dozens of times hunting for a “nice” phrase either — strong preferences shrink the space you're really choosing from.
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Frequently asked questions
Where does the word list come from?
It's a list of 1,790 short (3–8 letter), common, easy-to-spell English words curated for MockFox, similar in spirit to the EFF's short word lists. The entropy shown uses the exact list size.
Is “correct horse battery staple” still a good idea?
The method is — four random words was the XKCD example. Today, use five or more words, and never that exact phrase.
Should I use spaces as separators?
Spaces are easy to type, but some sites strip or reject them. A hyphen or period is the most widely accepted.
Is anything sent to a server?
No. Everything is generated by JavaScript in your browser, so nothing you type or generate is uploaded, logged or stored. It keeps working offline once the page has loaded.
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