🔑 Password Generator & Strength Analysis
Generate secure passwords and automatically analyze strength, supports custom character sets
Generation Options
Length:
Strength Analysis
Estimated Crack Time
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Strength Score 0 / 100
Waiting for password analysis
Password Length
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Entropy (bits)
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Charset Size
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Character Types
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⚠️ Security Tip:
This analysis is based on brute-force estimation. Actual attacks may use more efficient methods like dictionary attacks. Strong passwords should contain uppercase and lowercase letters, numbers, and symbols, with a minimum length of 12 characters.
💡 Instructions:
• Generate:Select options and click🎲Generate, auto-analyze strength
• Manual Input:Enter password directly in input box, real-time strength analysis
• Analyze:Click🔍Analyze Strength button or press Ctrl+Enter
• Higher entropy = more secure password (ideal: ≥128 bits)
• Ideal password: 16+ characters, includes uppercase/lowercase letters, numbers, and symbols

Secure Password Generator & Strength Analyzer

Generate cryptographically secure random passwords and analyze their strength with this tool. The password generator uses the Web Crypto API to ensure true randomness, while the strength analyzer calculates entropy, estimates crack time, and provides detailed security metrics.

How to Generate Secure Passwords

  1. Select Character Types: Choose from lowercase letters, uppercase letters, numbers, and symbols.
  2. Set Password Length: Use the slider or input field to set the desired length (4-64 characters).
  3. Generate Password: Click the "🎲 Generate Password" button to create a secure random password.
  4. Analyze Strength: The tool automatically analyzes the generated password's strength.
  5. Copy to Clipboard: Use the copy button to securely copy the password.

Understanding Password Strength Metrics

  • 📊 Entropy (Bits): Measures password randomness. Higher entropy = more secure. Ideal: ≥128 bits.
  • 📊 Crack Time: Estimated time for a brute-force attack at 1 billion guesses/second.
  • 📊 Character Set Size: Number of possible characters used in the password.
  • 📊 Character Types: Which character categories are included (lowercase, uppercase, numbers, symbols).

Password Strength Guidelines

  • ✓ Minimum Length: Use at least 12 characters for basic security, 16+ for important accounts.
  • ✓ Character Variety: Include uppercase, lowercase, numbers, and symbols for maximum entropy.
  • ✓ Avoid Patterns: Don't use dictionary words, common patterns, or personal information.
  • ✓ Unique Passwords: Use different passwords for different accounts to limit breach impact.
  • ✓ Password Manager: Consider using a password manager to store and generate passwords securely.

Entropy Calculation Formula

Password entropy is calculated using the formula: E = L × log₂(N)

  • E: Entropy in bits
  • L: Password length (number of characters)
  • N: Size of the character set (number of possible characters)
  • log₂: Base-2 logarithm

Example: An 8-character password using only lowercase letters (N=26) has E = 8 × log₂(26) ≈ 37.6 bits of entropy. Adding uppercase, numbers, and symbols increases N to 94, giving E = 8 × log₂(94) ≈ 52.3 bits.

Crack Time Estimation

The tool estimates crack time assuming an attacker can make 1 billion (10⁹) guesses per second. This is a conservative estimate - modern GPUs can perform billions of hash calculations per second. For context:

  • 40 bits: Seconds to minutes (weak)
  • 64 bits: Days to weeks (moderate)
  • 80 bits: Years to decades (strong)
  • 128 bits: Billions of years (very strong)
🔒 Security Note:

This tool uses the Web Crypto API's crypto.getRandomValues() for cryptographically secure random number generation. All password generation and analysis happens entirely in your browser - no data is sent to any server. For maximum security, consider using a dedicated password manager like Bitwarden, 1Password, or KeePass for long-term password storage.