A long passphrase made of random words is the modern recommendation for master passwords and any account you must remember: easy for you, hard for anyone else to guess. This generator picks words with your browser’s secure random source and shows a conservative entropy estimate so you can judge strength at a glance.
How it works
Words are drawn from a 260-word readable list using crypto.getRandomValues with rejection sampling, which discards biased draws so every word is exactly equally likely. The entropy estimate is built up additively:
- Each word adds
log2(260) ≈ 8.02bits. - Adding a random number contributes
log2(100) ≈ 6.6bits. - Adding a symbol contributes
log2of the symbol-set size.
So entropy scales linearly with your chosen word count — more words, more bits, exponentially more guessing effort for an attacker.
Why passphrases beat complex short passwords
A random 8-character password using uppercase, lowercase, digits, and symbols draws from a space of about 95 characters per position, giving roughly 52 bits of entropy — less than a 7-word passphrase from this tool. The passphrase is also radically easier to remember and type accurately.
The original NIST password guidance that encouraged P@ssw0rd-style complexity has been revised. Current NIST guidance (SP 800-63B) explicitly recommends length over complexity, favors passphrases, and notes that complex-but-short passwords cause users to choose weak patterns that negate the apparent security.
Entropy and attacker effort
| Words | Approx. entropy | Illustrative offline guesses needed |
|---|---|---|
| 4 | ~32 bits | ~4 billion |
| 5 | ~40 bits | ~1 trillion |
| 6 | ~48 bits | ~281 trillion |
| 7 | ~56 bits | ~72 quadrillion |
These are approximate illustrative figures assuming optimal dictionary attacks on the specific word list. For an online service with rate limiting, even 32 bits is practically uncrackable. For a password manager master password or full-disk encryption key, aim for 48 bits or more.
When to use each word count
4 words (~32 bits): Acceptable for low-value accounts where you need to remember the password, especially with multi-factor authentication active.
5 words (~40 bits): Good general-purpose choice for most account passwords. Comfortable to memorize with brief repetition.
6 words (~48 bits): Recommended for password manager master passwords, email accounts, and anything that would cause serious harm if compromised.
7+ words: Full-disk encryption, long-term archival, or any situation where you have no rate-limit protection and the dataset could be brute-forced offline.
The separator and policy compliance
Many sites require digits and symbols even when length would be sufficient. The separator option lets you use a hyphen, period, or underscore between words, and the number/symbol append options satisfy most complexity policies without destroying memorability. For example: brave-cedar-flint-meadow-7! meets virtually every complexity policy while still being easy to type and recall.
Everything runs locally in your browser — nothing is ever uploaded.