Random Password Generator
Create strong, secure random passwords with advanced customization. Includes strength meter, entropy bits, crack time estimates, and pronounceable password options.
How to Use the Password Generator
Create cryptographically secure passwords tailored to your security needs. The tool automatically generates a password on page load and updates instantly when you change any setting.
- Choose a preset (Basic, Strong, Ultra, or PIN) or customize manually
- Adjust password length using the slider (4-128 characters)
- Select character types: uppercase, lowercase, numbers, symbols
- Enable exclude ambiguous to avoid confusing characters (0/O, 1/l/I)
- Try pronounceable mode for passwords easier to remember and type
- View strength metrics: strength rating, entropy, and crack time
- Click Copy Password to save to clipboard
Password Strength Explained
Very Weak (0-20%): Passwords with very low entropy, easily cracked in seconds. Avoid using these for any account.
Weak (20-40%): Short passwords or those using limited character sets. Can be cracked in minutes to hours. Unsuitable for important accounts.
Fair (40-60%): Moderate length with some character variety. May be cracked in days to weeks. Acceptable for low-security accounts only.
Good (60-80%): Strong passwords with good length and character diversity. Would take months to years to crack. Suitable for most accounts.
Strong (80-90%): Very strong passwords with high entropy. Would take decades to crack with current technology. Recommended for important accounts.
Very Strong (90-100%): Extremely secure passwords with maximum entropy. Would take centuries to millennia to crack. Ideal for critical accounts like banking, email, and password managers.
Understanding Entropy and Crack Time
Entropy measures password randomness in bits. Higher entropy means more possible combinations, making brute-force attacks harder. A password with 60 bits of entropy has 2^60 (over 1 quintillion) possible combinations. For strong security, aim for at least 60-80 bits.
Crack Time estimates how long it would take to guess your password using brute-force attacks with modern hardware. Calculations assume 10 billion guesses per second (achievable with GPU-based cracking). Real-world crack times vary based on attacker resources and attack methods.
Character Types affect password space size. Each type added (uppercase, lowercase, numbers, symbols) exponentially increases possibilities. Using all 4 types with 16 characters creates 95^16 combinations (roughly 10^31), providing 105 bits of entropy.
Password Security Best Practices
- Length Matters Most: A 16-character password with mixed types is far stronger than an 8-character one with all types
- Use Unique Passwords: Never reuse passwords across accounts. One breach compromises all accounts with the same password
- Use a Password Manager: Store generated passwords in a secure password manager like Bitwarden, 1Password, or KeePass
- Enable 2FA: Two-factor authentication adds critical security even if your password is compromised
- Avoid Personal Information: Don't use names, birthdays, addresses, or dictionary words
- Change Compromised Passwords: If a service you use is breached, change that password immediately
- 12+ Characters Minimum: For critical accounts, use at least 12-16 characters with all character types