12 character password generator
Made on your device. Never sent or stored.
A random 12 character password, generated on your device. Change the character types below; the length stays at 12 unless you move it.
Is 12 characters long enough?
Twelve characters is the length many security teams recommend as a practical minimum. With letters, digits and symbols it reaches about 77 bits, beyond any realistic offline attack on a fast hash.
When to use it: A sensible minimum for everyday accounts when you use a password manager.
How strong is a 12 character password?
A random 12 character password from letters and digits has 71.5 bits of entropy. With symbols added it has 77.3. Here is how that translates into guessing time for each character set.
| Characters | Pool | Bits | Fast hash | Slow hash |
|---|---|---|---|---|
| Digits only | 10 | 39.9 | 50 seconds | 2 years |
| Lowercase letters | 26 | 56.4 | 55 days | 151,198 years |
| Letters, both cases | 52 | 68.4 | 619 years | 619 million years |
| Letters and digits | 62 | 71.5 | 5,112 years | 5 billion years |
| All four types (this site) | 87 | 77.3 | 297,918 years | 298 billion years |
These figures only hold for random passwords like the ones above. A 12 character password you made up, with words, names or dates, is guessed far sooner. Test one with the strength checker.
Questions
How many combinations does a 12 character password have?
With the 87 characters used here, 87 to the power 12, about 1023. With letters and digits only, 62 to the power 12, about 1021.
Is this password stored anywhere?
No. It is generated in your browser with the Web Crypto API and never sent to a server.
Sources
- SP 800-63B-4, section 3.1.1.2: Password Verifiers, National Institute of Standards and Technology. Checked 18 October 2026.