Password Generator
Generate results with the Password Generator — set your parameters and get cryptographically-random output instantly.
Reviewed by Daniel Agrici, Founder & Lead Developer · Editorial policy
Password Generator Formula
Entropy = log2(pool_size^length)
Password entropy measures the unpredictability of your password. A larger character pool and longer length each multiply the entropy exponentially.
Password Generator — Worked Examples
Example 1: 16-char password with all character types
Problem:Length: 16, uppercase + lowercase + numbers + symbols enabled
Solution:Pool: 95 chars (26 uppercase + 26 lowercase + 10 digits + 33 symbols). Entropy = log2(95^16) ≈ 105 bits
Result:Extremely strong password — infeasible to brute-force with current hardware
Password Generator — Frequently Asked Questions
How secure is a randomly generated password?
A randomly generated password using cryptographic randomness (like the Web Crypto API) is extremely secure. Unlike human-chosen passwords, it has no patterns, dictionary words, or predictable sequences. Each character is independently random, making brute-force attacks computationally infeasible for passwords of sufficient length.
What makes a password strong?
Two factors dominate password strength: length and character variety. Length matters most — each additional character multiplies the number of possible combinations. Character variety expands the pool: using uppercase, lowercase, digits, and symbols increases the pool from 26 to 95 characters. A 16-character password using all four types has over 100 bits of entropy.
What is password entropy and how is it calculated?
Password entropy measures unpredictability in bits. It is calculated as: Entropy = log2(pool_size ^ length). For a 16-character password drawn from a 95-character pool (all character types), entropy = log2(95^16) ≈ 105 bits. Each additional bit doubles the difficulty to guess. NIST guidelines consider 80+ bits strong and 100+ bits very strong.
Should I use a password manager?
Yes. A password manager lets you use a unique, long, random password for every account without memorizing them. This prevents credential reuse attacks — the most common cause of account breaches. Store generated passwords in a reputable manager such as Bitwarden, 1Password, or KeePass rather than reusing simpler passwords.