How to use it
- Set the length with the slider.
- Choose the character types. Leaving out look-alike characters helps if you will read the password aloud or type it from paper.
- Press Copy, or New password for another one. Any change of settings makes a new password.
How strength is measured
For a random password, strength depends only on its length and on how many different characters it can use:
entropy = length × log₂(number of possible characters)
With all four types there are 89 possible characters (26 + 26 + 10 + 27 symbols), so each character adds about 6.5 bits. A 16-character password has about 103 bits.
| Entropy | Strength |
|---|---|
| under 40 bits | weak |
| 40–59 bits | fair |
| 60–79 bits | strong |
| 80 bits and more | very strong |
Good habits
- Use a different password for every account; a leak on one site then does not open the others.
- Keep passwords in a password manager instead of a note or a spreadsheet.
- Turn on two-factor authentication where it is offered: even a strong password can be phished.