Password Generator
Generate cryptographically secure passwords and passphrases with custom character sets and entropy scoring.
Password Generator
CSPRNG Web Crypto security with Shannon entropy calculation.
âī¸ Security Settings
What is the Password Generator?
The Password Generator is a high-security, browser-only tool for generating strong, uncrackable passwords and memorable passphrases. Weak, reused, or predictable passwords remain the #1 vector for data breaches and account takeovers.
Our tool uses the browser's native Web Crypto API (`window.crypto.getRandomValues`) to generate true cryptographically secure pseudorandom numbers (CSPRNG). It calculates exact Shannon Entropy ($H = L \log_2 N$) in bits to give you a mathematically rigorous score of how hard your password is to brute-force.
Key Features
- CSPRNG Security: Zero weak `Math.random()` usage. All randomness is derived from OS hardware entropy.
- Custom Character Sets: Toggle Uppercase (`A-Z`), Lowercase (`a-z`), Digits (`0-9`), Special Symbols (`!@#$%^&*`), and Exclude Similar Characters (`i, l, 1, O, 0`).
- Memorable Passphrase Mode: Generate readable multi-word passphrases (e.g. `correct-horse-battery-staple`) using an EFF-inspired wordlist.
- Real-Time Entropy Meter: Displays entropy in bits ($H$) and estimated time to crack at 100 billion guesses per second.
- Bulk Generator: Generate up to 50 secure passwords at once.
- 100% Private: Passwords are generated strictly inside client-side RAM and never transmitted anywhere.
How Does the Password Generator Work?
1. Choose Type: Select Random Password or Memorable Passphrase mode.
2. Set Length: Adjust password length slider (8 to 128 characters).
3. Select Character Sets: Toggle uppercase, lowercase, numbers, and special symbols.
4. Check Strength Meter: Ensure entropy is above 60+ bits (Strong) or 80+ bits (Very Strong).
5. Copy Securely: Click Copy to Clipboard. Password is cleared from memory when tab closes.
Formula & Calculation Method
Shannon Entropy Formula:
$$H = L \times \log_2(N)$$
Where:
- $L$ = Password length (number of characters)
- $N$ = Pool size of available character set
- Lowercase ($a-z$): $N = 26$
- Lower + Upper ($a-z, A-Z$): $N = 52$
- Alpha + Numbers ($a-z, A-Z, 0-9$): $N = 62$
- Full Set (+ Symbols): $N = 94$
Time to Crack (Brute Force at $10^{11}$ guesses/sec):
$$\text{Seconds} = \frac{2^{H-1}}{10^{11}}$$
Example Calculation
Password: `k9#mP2$xL8!vQ4#w` (Length 16, Full Set $N=94$)
- Entropy: $16 \times \log_2(94) = 16 \times 6.5546 = 104.8 \text{ bits}$
- Strength Tier: Very Strong (Military/Enterprise Grade)
- Time to Crack: ~34 trillion years at 100 billion guesses/sec
Frequently Asked Questions
**Shannon Entropy Formula:** $$H = L \times \log_2(N)$$ Where: - $L$ = Password length (number of characters) - $N$ = Pool size of available character set - Lowercase ($a-z$): $N = 26$ - Lower + Upper ($a-z, A-Z$): $N = 52$ - Alpha + Numbers ($a-z, A-Z, 0-9$): $N = 62$ - Full Set (+ Symbols): $N = 94$ **Time to Crack (Brute Force at $10^{11}$ guesses/sec):** $$\text{Seconds} = \frac{2^{H-1}}{10^{11}}$$
Disclaimer: All developer utilities run 100% locally in your browser. None of your code, tokens, passwords, or input data are sent to or stored on remote servers.