Passphrase Generator
Generate memorable random passphrases
Passphrase Generator is a free online tool from BrowserUtils that generate memorable random passphrases. It runs entirely in your browser — your data never leaves your device. No account required.
prior-occur-drift-upper
Entropy: ~37 bits (661-word list, 4 words)
How to use Passphrase Generator
- 1Paste or type your input into the editor above.
- 2The tool processes your data instantly — right in your browser, with nothing sent to a server.
- 3Copy the result with one click or continue editing your input.
About Passphrase Generator
Free online passphrase generator. Create strong, memorable passphrases from random words using the diceware method, with configurable word count and separator. This tool runs entirely in your browser — your data is never sent to a server. Just paste your input, get instant results, and copy with one click. No sign-up or installation required.
Passphrase Generator specs
- Runtime
- 100% client-side (browser)
- Built on
- Web Crypto API (SubtleCrypto) for hashing and crypto.getRandomValues for secure randomness
- Cost
- Free — no account, no rate limits, no usage caps
- Browser support
- Chrome 90+, Firefox 88+, Safari 14+, Edge 90+
- Last updated
- July 2, 2026
- Part of
- 299 developer tools on BrowserUtils (100% client-side)
Questions
How secure is a passphrase?
Each word from a 7,776-word list (the standard EFF/diceware wordlist) contributes about 12.9 bits of entropy. A 4-word passphrase has ~51 bits, 5 words ~64 bits, and 6 words ~77 bits. A 6-word passphrase would take roughly 5 million years to brute-force at 1 trillion guesses per second — strong enough for any normal use case.
How many words should my passphrase have?
Use 4 words for routine accounts, 5 for sensitive ones (email, banking), and 6 or more for master passphrases (password manager, full-disk encryption, SSH keys). Each additional word roughly multiplies the brute-force time by 8,000.
What is the diceware method?
Diceware, invented by Arnold Reinhold in 1995, generates passphrases by rolling five physical dice per word and looking up the resulting five-digit number in a 7,776-entry wordlist. Software passphrase generators use cryptographically secure random numbers instead of physical dice but produce the same per-word entropy.
What word list is used?
This tool generates each word using cryptographically secure random numbers (Web Crypto API, crypto.getRandomValues) selected from a wordlist of common English words.
Is a passphrase more secure than a password?
A randomly generated passphrase of 5 or more words is typically stronger than the kind of 8–12 character password humans actually choose, because human-picked passwords cluster around predictable patterns. A truly random 12-character password with mixed character types has comparable entropy to a 5-word passphrase.
What is a good passphrase example?
A randomly generated 6-word passphrase looks like "plunder reroute roving juvenile reset prankish" — strong, easy to type, and memorable after a few repetitions. Don't reuse this exact one; generate your own.
Should I add numbers or symbols to my passphrase?
Not really. Adding a "!1" suffix to a 4-word passphrase adds almost no entropy — attackers test those mutations cheaply. If you need more strength, add another word: that contributes ~13 bits, far more than any character substitution.
Is this passphrase generator safe to use online?
Yes. Passphrases are generated entirely in your browser using the Web Crypto API. The generated passphrase never leaves your device, is never sent to a server, and is never logged. The page makes no network requests after loading.
Can I customize the separator between words?
Yes — choose spaces, hyphens, periods, or any character. Hyphens are a popular default because they survive autocorrect on mobile keyboards. The separator itself adds a tiny amount of entropy if you randomize it, but the dominant contributor to strength is the word count.
When should I use a passphrase vs a random password?
Use a passphrase for anything you have to type from memory: your password manager's master passphrase, laptop login, full-disk encryption keys, SSH key passphrases. For every other account, let your password manager generate a long random character string per site — you don't need to remember those.
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