π Password Generator
Generate cryptographically secure random passwords instantly.
How to Use This Tool
Set the length using the slider and check the character sets you want included. Click the refresh button next to the password field to generate a new one at any time. Use Bulk Generate for multiple passwords at once.
Drag the length slider to set your desired password length (8 to 128 characters).
Check or uncheck character sets: uppercase, lowercase, numbers, symbols, and exclude ambiguous characters.
The password generates automatically. Click the refresh button to get a new one instantly.
Copy the password, or use Bulk Generate with a count to get multiple passwords at once.
Password Entropy: Why Length Matters More Than Complexity
Password strength is measured in bits of entropy: Entropy = logβ(pool_size ^ length). The pool is the number of possible characters, and the length is how many characters are in the password. Doubling the pool size (say from 26 lowercase letters to 52 upper and lowercase) adds only 1 bit per character of entropy. Adding one more character to the length adds logβ(pool_size) bits. For a 94-character pool (all printable ASCII), each additional character adds about 6.5 bits of entropy. A 16-character password with the full character set has roughly 105 bits of entropy, which makes brute force computationally impossible with current hardware. A 12-character password with only lowercase letters has about 56 bits, which is crackable with dedicated hardware given enough time. Passwords are also weakened if the attacker knows the pattern: adding a capital letter at the start and a number and symbol at the end (Password1!) is a well-known pattern that dictionary attacks account for. Random character generation avoids patterns entirely. This tool uses crypto.getRandomValues(), which is the same cryptographically secure random source browsers use for TLS key material, not the weaker Math.random().
Common Use Cases
Frequently Asked Questions
Is this password generator secure?
Yes β it uses window.crypto.getRandomValues() which is a cryptographically secure pseudorandom number generator (CSPRNG) available in all modern browsers. Passwords are never sent to any server.
How long should a password be?
Minimum 12 characters for most accounts; 16+ for sensitive accounts. Each additional character exponentially increases brute-force resistance.
What makes a strong password?
Length (12+ chars), complexity (mix of uppercase, lowercase, numbers, symbols), randomness, and uniqueness (different for each account).
Should I store generated passwords?
Use a password manager (Bitwarden, 1Password, KeePass) to store passwords securely. Never save passwords in plain text or browser notes.
What is entropy in passwords?
Password entropy measures unpredictability in bits. Entropy = logβ(character pool ^ length). 80+ bits is considered strong; 100+ bits excellent.