Passwords
A passphrase you can remember and nobody can guess.
Words picked at random from the EFF’s list of 7,776. Each word adds 12.9 bits of entropy. Six words is plenty for almost anything; use seven or more for a password manager’s master password.
How long to crack it
Average time to guess it, assuming the attacker knows you used this word list and how many words.
Why dice
People pick predictable words even when they try to be random. Rolling five dice gives a number from 11111 to 66666, and each number maps to a word on the EFF large word list. Generate mode does the same with your browser’s cryptographic random number generator. The word list is part of this page, so nothing is sent anywhere.
Use a passphrase where you have to type or remember it: your password manager, your computer, your phone. Everywhere else, let the password manager generate one. Then check your old passwords andadd a second factor.
Word list by the Electronic Frontier Foundation, licensed CC BY 3.0 US.