What is a passphrase?
A passphrase is a password made of several random words, like velvet-anchor-pumpkin-hazard-lyric. Its strength does not come from the words
being obscure. It comes from the words being picked at random from a large
list, so an attacker who knows the list still has to try every combination.
That is also why you should not choose the words yourself. People pick related or famous phrases, and cracking tools try those first. Let the generator choose.
How many words do you need?
Each word adds about 12.9 bits (log2 of 7,772). Times below are for an offline attack against a stolen database at 10 billion guesses per second, trying every combination:
| Words | Entropy | Time to try them all |
|---|---|---|
| 4 | 52 bits | about 4 days |
| 5 | 65 bits | about 90 years |
| 6 | 78 bits | about 700,000 years |
| 7 | 90 bits | about 5 billion years |
Use five words for everyday accounts and six or more for anything that guards other accounts. Real attacks are often slower than this, because sites that store passwords properly make each guess expensive, but plan for the worst case.
Passphrase or random password?
- Passphrase: for what you have to type or remember. Your computer login, your email, Wi-Fi you read out to guests, and the one password that opens your password manager.
- Random password: for everything you never type yourself. Make it with the password generator and let a password manager fill it.
Either way, use each one for a single account only. Not sure about a password you already use? Check it with the password strength checker.
Keep every password in one place
Save passphrases and generated passwords in DroidPass, an AES-256 encrypted vault with fingerprint and Face ID unlock, a built-in 2FA authenticator, and offline access. Free to start.
Passphrase generator FAQ
Is a passphrase safer than a password?
Not automatically. Strength comes from randomness and length. A passphrase of 6 words picked at random from 7,772 has about 78 bits of entropy, which is stronger than most passwords people invent and far easier to type. A 16-character random password is stronger still, about 100 bits, but hard to remember. Use passphrases for what you must type or memorize, and random passwords saved in a password manager for everything else.
How many words should my passphrase have?
Five words (about 65 bits) for everyday accounts, six or more (78+ bits) for anything that protects other accounts: your email, your computer login, or a password manager. Each extra word multiplies the number of guesses by 7,772.
Is this passphrase generator safe to use?
Yes. Words are picked in your browser with the Web Crypto API (crypto.getRandomValues) and rejection sampling, so every word is equally likely. Nothing is sent to a server, stored or logged, and the page keeps working if you go offline after it loads.
Where do the words come from?
The EFF Large Wordlist, published by the Electronic Frontier Foundation for dice-generated passphrases. Its words are common, easy to spell and distinct from each other. We use the 7,772 entries without a hyphen, so a hyphen separator is never ambiguous.
Do capitals, numbers or symbols make it stronger?
Only a little. Capitalizing every word adds nothing, because it is applied the same way each time. "Add a number" puts one random digit on one random word, adding about 5 to 6 bits. Adding a word adds about 13 bits, so length is the better lever. Turn the extras on when a site insists on them.
Keep reading
How to create a strong password →
Random password generator →
How secure is my password? Test it →
Word list: EFF Large Wordlist, Electronic Frontier Foundation, CC BY 3.0 US.