Free toolSecurity

Passphrase Generator

Create memorable, high-entropy passphrases from random words.

39 bits of entropy

About this tool

A passphrase strings together several random words — easy for a human to remember, but long enough to be very hard to guess. It's often a better choice than a short tangle of symbols you'll never recall.

Choose how many words, your separator, and whether to capitalize or add a number. Words are picked with the browser's cryptographically secure random generator, and the estimated entropy is shown so you can see how strong each passphrase is. Nothing is stored.

Frequently asked questions

Yes, when the words are chosen randomly. Four random words from a sizeable list already resist brute-force attacks; adding words or a number increases entropy further.

Words are selected using the Web Crypto API's cryptographically secure random generator, entirely on your device. No passphrase is transmitted or saved.

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