UFOZoo

Password Generator — Free Create Strong Random Passwords

Create strong, secure passwords with customizable length and character sets. Uses Web Crypto API for cryptographically secure generation. Browser-based.

Features

  • ✓Cryptographically secure generation using Web Crypto API's CSPRNG — the same technology used by banks and government agencies
  • ✓Real-time strength analysis with entropy calculation and estimated crack time based on modern GPU capabilities
  • ✓Customizable character sets — choose uppercase, lowercase, numbers, and symbols to meet specific site requirements
  • ✓Exclude similar characters option to avoid confusion between O/0, I/l/1 when manually typing passwords
  • ✓Memorable passphrase mode using random word combinations — perfect for master passwords you need to memorize
  • ✓Password history saves last 10 generated passwords in browser session storage for quick access
  • ✓Flexible length control from 8 to 128 characters with quick presets for common lengths
  • ✓100% client-side processing — passwords never travel over network or touch any server

How to Use

  1. 1Select your desired password length using the slider (recommended: 16+ characters for maximum security)
  2. 2Choose which character types to include: uppercase, lowercase, numbers, and/or symbols
  3. 3Toggle 'Exclude Similar' to avoid confusing characters like O/0 and I/l/1
  4. 4Switch to 'Passphrase' mode for memorable word-based passwords
  5. 5Click 'Generate' to create a new random password instantly
  6. 6Use the copy button to copy the password to your clipboard
  7. 7View password history to access previously generated passwords
  8. 8Check the strength indicator to ensure your password meets security requirements

Frequently Asked Questions

Is this password generator safe to use?

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Absolutely. All password generation happens entirely in your browser using the Web Crypto API. Your passwords are never transmitted to our servers, never logged, and never stored. We have zero knowledge of what passwords you generate.

How does the cryptographically secure generation work?

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We use the browser's built-in crypto.getRandomValues() API, which accesses your operating system's entropy pool—random data gathered from hardware timing, mouse movements, and other unpredictable sources. This is the same technology banks and governments use.

What password length should I use?

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For general accounts: 12-16 characters. For banking and sensitive accounts: 20+ characters. Each additional character exponentially increases security—a 20-character password is billions of times stronger than a 12-character one.

What is password entropy?

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Entropy measures password randomness in bits. Higher entropy = harder to crack. Our tool calculates entropy based on length and character diversity. 80+ bits is strong, 100+ bits is very strong, 128+ bits is military-grade.

Can generated passwords be cracked?

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Theoretically any password can be cracked given infinite time, but a 16-character random password would take centuries to crack with current technology. Our strength indicator shows estimated crack times based on modern GPU capabilities.

What are 'similar characters' and why exclude them?

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Characters like O (letter) and 0 (zero), or I (uppercase i), l (lowercase L), and 1 (one) look identical in many fonts. Excluding them prevents confusion when manually typing passwords.

What's the difference between password and passphrase?

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Passwords use random characters (K9#mP2$v). Passphrases use random words (correct-horse-battery). Passphrases are easier to memorize while remaining secure due to length. Both are generated cryptographically secure.

Why shouldn't I reuse passwords?

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If one service is breached and your password exposed, attackers can access all your other accounts using the same password. This 'credential stuffing' attack is extremely common. Use unique passwords for every account.

How do I generate a password that meets specific website requirements?

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Many websites require at least one uppercase letter, one number, and one special character. Use the character type checkboxes to enforce these requirements. Set a length of 12-16 characters for most sites. The strength indicator shows real-time feedback on your configuration before you generate.

How does the password history feature work?

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The password history stores your last 10 generated passwords in browser session storage for quick access. You can review or copy previously generated passwords without reconfiguring. The history is temporary — it is cleared when you close your browser tab. This is a convenience feature, not a replacement for a dedicated password manager.

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