Password Generator
Generate strong, random passwords with custom length and character set rules (uppercase, lowercase, digits, symbols).
How to use the Password Generator
- Enter your inputs into the Password Generator above.
- Results update instantly as you type — no submit button needed.
- Adjust any value to see how the result changes in real time.
Password entropy
Bits of entropy = log₂(charset_size^length)
Strength depends on length and character set. A 12-character password from a 94-character set has log₂(94¹²) ≈ 79 bits of entropy — strong enough that brute force takes longer than the age of the universe.
Worked example
A 16-character password from {lower, upper, digit, symbol} (~94 chars): example "K7#mZp2$qN8wB4xY". Entropy ≈ 105 bits. To brute force at 1 trillion guesses/sec: ~10^15 years.
Frequently asked questions
What length should I use?
12+ characters with mixed character classes is the baseline. 16+ is recommended for high-security accounts. For passphrases (multiple words), 4+ random words from a large dictionary is comparable.
Are random strings or passphrases better?
Comparable security at similar entropy. Random strings need a password manager; passphrases are more memorable. Pick what you'll actually use.
Should I reuse passwords?
Never. A breach at one site exposes the password at every site using it. Use a password manager to generate and store unique strong passwords for every account.