12-character password generator
This generator creates a random 12-character password using uppercase and lowercase letters, numbers, and symbols — 77.1 bits of entropy drawn from 1.6 x 10^23 possible combinations. The minimum that most current guidance will still defend.
- Entropy
- 77.1 bits
- Possible passwords
- 1.6 x 10^23
- GPU, fast hash
- 26 thousand years
- GPU, PBKDF2 600k
- 16 billion years
Is 12 characters enough?
Twelve random characters is the point where offline brute force stops being an afternoon project. It is the floor recommended in most enterprise policies today, and it is the shortest length worth using for an account you care about.
Compared with a 10-character password, this is roughly 7,396 times more work for an attacker — the cost of guessing grows by a factor of 86 for every single character you add.
When to use a 12-character password
Everyday accounts where you also have two-factor authentication enabled, or where the site is known to hash passwords properly with bcrypt, scrypt, or Argon2.
What to watch out for
Twelve characters assumes the site stores your password with a slow hash. If it leaks an unsalted SHA-1 database, twelve is a lot less comfortable than the headline number implies.
How long this password survives each attack
"Time to crack" is meaningless without naming the attack. The same password fails in an afternoon or outlives the sun depending on how the website stored it. These are average times — half the keyspace — for this password:
| Attack scenario | Guesses / second | Average time |
|---|---|---|
| Throttled login form | 100 | 26 trillion years |
| Stolen database, unsalted fast hash | 100 billion | 26 thousand years |
| Stolen database, PBKDF2 with 600,000 iterations | ~167,000 | 16 billion years |
The third row is why key stretching matters so much. MoolKey runs PBKDF2 at 600,000 iterations for the same reason: it costs you a fraction of a second and costs an attacker a factor of 600,000.
You still have to keep it somewhere
A 12-character random string is not memorable, and pretending otherwise is how people end up with a sticky note. Either store it in a password manager, or use a generator that can recreate it on demand from one phrase you already remember — which means there is no stored copy for anyone to steal.
12-character password questions
- Is a 12-character password strong enough?
- A random 12-character password using uppercase, lowercase, numbers, and symbols carries 77.1 bits of entropy. The minimum that most current guidance will still defend. Against an offline attack on a fast hash at 100 billion guesses per second, the average time to crack it is 26 thousand years.
- How many 12-character passwords are possible?
- With a pool of 86 symbols there are 1.6 x 10^23 possible 12-character passwords. That figure only protects you if your password was chosen at random from all of them — a password you invented sits in a far smaller set that attackers search first.
- How long does it take to crack a 12-character password?
- It depends entirely on how the site stored it. On a rate-limited login form at 100 guesses per second: 26 trillion years. Against a stolen database of fast hashes on a GPU cluster: 26 thousand years. Against a properly stretched PBKDF2 hash with 600,000 iterations: 16 billion years.
- Is this 12-character generator safe?
- Yes. It runs entirely in your browser using crypto.getRandomValues, the cryptographic random source provided by your operating system. No password is transmitted, logged, or stored. You can disconnect from the network and the generator still works.
More free tools
Every tool runs in your browser without an account. The generators, strength checker, and entropy calculator keep inputs local. The breach checker sends only a five-character hash prefix to Have I Been Pwned.
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Breach check
A breach check tells you whether a password already appears in leaked data.
Entropy calculator
Password entropy measures how many guesses an attacker needs, expressed in bits.
Make one account easier today.
Start with the password you keep reusing or the bank card that still shares a PIN. MoolKey is free, and you do not need to move everything at once.