Why passphrases work
Each word is picked at random from a list of 7,776, which adds about 12.9 bits of entropy per word. Six words give roughly 77 bits, far beyond what is practical to guess, and a phrase of six ordinary words is much easier to remember than a random 12-character string.
How it is generated
Words are chosen with your browser's secure random number generator (crypto.getRandomValues) using rejection sampling, so every word is equally likely. Nothing is sent or stored.
Using them well
- Keep the words random. Do not swap them for ones you like better, because that lowers the entropy.
- Use a password manager for most accounts, and a passphrase for the master password and for devices.
- Do not reuse a passphrase across accounts.
Word list: EFF Large Wordlist for Passphrases by the Electronic Frontier Foundation, licensed under CC BY 3.0 US. Check any password with the leak checker.