How Long Should a Password Be?

Length is the single most important property of a password. Every character you add multiplies the number of possible combinations — the table below shows what that does to cracking time in practice.

Cracking time by length and character set

Lengtha–z (26)a–z, A–Z (52)+ 0–9 (62)+ !@#… (95)
6instantlyinstantlyinstantlyinstantly
8instantly27 seconds109 seconds55 minutes
1071 seconds20 hours5 days346 days
1213 hours6 years51 years8,561 years
14373 days16,746 years196,494 years77M years
16691 years45M years755M years697B years
20316M years331T years11,161T years56,798,667T years

Average time for an offline attack on a leaked password hash at ~1 trillion (10¹²) guesses per second, assuming randomly chosen characters. Human-chosen passwords fall far faster.

Why length beats complexity

A symbol or a digit makes each position a little harder to guess, but an extra character multiplies the difficulty of the whole password. Twelve simple characters therefore beat eight “complex” ones — and a long password is also easier to remember than a short cryptic one.

Our recommendations

Use at least 12 characters with a full character set for everyday accounts, 16 or more for email and anything holding payment data, and 20+ — or a passphrase of several random words — for a password manager master password. Email deserves the extra care: whoever controls your inbox can reset most of your other passwords.

A service’s minimum is not a recommendation

Many services still accept 6 or 8 characters. That is the floor below which they refuse the password — not a statement that it is safe. As the table shows, an 8-character password falls quickly to an offline attack no matter how many symbols it contains.