How to Generate Strong Passwords: A Complete Security Guide
Learn the science of password security, understand entropy, and discover why random passwords generated by tools like ours are far more secure than anything you could create yourself.
1. What Makes a Password Strong?
A strong password is one that resists two primary attack vectors: guessing and brute force. The strength of a password is measured in entropy - basically, how unpredictable it is.
Key Characteristics of Strong Passwords:
- Length: At least 16 characters recommended
- Randomness: No patterns, words, or predictable sequences
- Character variety: Mix of uppercase, lowercase, numbers, and symbols
- Uniqueness: Never reused across multiple sites
Important: A password like Tr0ub4dor&3 looks complex but only has about 28 bits of entropy. A randomly generated 16-character password like 8H9$kL2@nPq#5xRw has over 90 bits of entropy and is exponentially more secure.
2. Understanding Password Entropy
Entropy is measured in bits. Each additional bit doubles the number of possible combinations, making a password twice as hard to crack through brute force.
Entropy Breakdown by Password Type:
| Password Type | Entropy (bits) | Security Level |
|---|---|---|
| 6-character lowercase | ~28 bits | Very Weak |
| 8-character mixed case + numbers | ~52 bits | Weak |
| 12-character random all types | ~76 bits | Moderate |
| 16-character random all types | ~102 bits | Strong |
| 20-character random all types | ~128 bits | Very Strong (Recommended) |
Our Strong Password Generator creates 16-character passwords with ~102 bits of entropy - virtually uncrackable with current technology.
3. Password Length vs. Complexity
Which is more important: length or character variety? The short answer is length wins, but the best approach is both.
The Math Behind It:
- Lowercase only: 26 possibilities per character
- Mixed case: 52 possibilities per character
- With numbers: 62 possibilities per character
- With symbols: ~90+ possibilities per character
A 16-character password with only lowercase letters (26^16) has approximately 75 bits of entropy. Adding uppercase, numbers, and symbols increases this to over 100 bits.
Recommendation: Use 16+ character passwords with all character types. The security gain from adding symbols far outweighs the minor inconvenience.
4. Common Password Mistakes to Avoid
Never Do These:
- Personal information: Birthdays, names, pets, addresses - all easily found on social media
- Dictionary words: Even with substitutions (p@ssw0rd), these are cracked instantly
- Patterns: 123456, qwerty, asdfgh are the first things attackers try
- Reuse: Using the same password everywhere means one breach compromises everything
- Keyboard patterns: adjacent keys form predictable patterns
- "clever" tricks: Replacing letters with similar numbers (a=@, e=3) doesn't fool modern crackers
5. Using Password Generators Effectively
Password generators use cryptographically secure random number generators (CSPRNG) to create truly unpredictable passwords. Our Strong Password Generator uses the Web Crypto API - the same security standard used for HTTPS encryption.
Best Practices:
- Generate a new random password for every account
- Use at least 16 characters
- Include all character types when allowed
- Never manually modify a generated password
- Store in a password manager immediately
Privacy Note: Our password generator runs entirely in your browser. No passwords are sent to any server. Generate with confidence.
6. Why You Need a Password Manager
Strong random passwords are impossible to remember - and that's exactly the point. Password managers solve this problem securely.
Benefits of Password Managers:
- Store unlimited complex passwords
- Auto-fill credentials securely
- Detect reused passwords
- Alert you to data breaches
- Share passwords securely with family/team
- Generate random passwords on the fly
Popular Password Managers:
- Bitwarden: Open source, excellent free tier
- 1Password: Premium features, great UX
- KeePassXC: Self-hosted, completely free
- Apple Keychain: Built into Apple devices
- Google Password Manager: Built into Chrome
7. Two-Factor Authentication (2FA)
Even the strongest password can be compromised through phishing, data breaches, or social engineering. Two-factor authentication adds a critical second layer of protection.
2FA Methods Ranked by Security:
- Hardware keys (YubiKey): Most secure, phishing-resistant
- Authenticator apps (TOTP): Very secure, time-based codes
- SMS codes: Better than nothing, but vulnerable to SIM swapping
- Email codes: Weakest option, but still adds protection
Use our 6-Digit PIN Generator to create secure PINs for devices that support numeric-only 2FA.
8. Frequently Asked Questions
How often should I change my passwords?
Modern security guidance recommends only changing passwords if there's a suspected breach. Strong, unique passwords for each account are more important than frequent changes. Focus on having unique passwords everywhere rather than rotating them.
Can I remember just one really strong password?
Yes! This is the password manager approach. Create one extremely strong master password (20+ characters) that you memorize, then let the password manager generate and store unique random passwords for every other account. Just never reuse your master password anywhere else.
Are password phrases (multiple words) secure?
Passphrases can be secure if they use truly random words chosen from a large dictionary. A 4-word passphrase has about 50-60 bits of entropy if words are randomly selected. However, random character passwords are still more secure for the same length. Use passphrases for your master password if it helps you remember something longer.
Is it safe to generate passwords online?
Only if the generator runs entirely client-side in your browser using cryptographically secure random generation. Our generator meets both criteria - it uses the Web Crypto API (CSPRNG) and processes everything locally. You can verify this by disconnecting from the internet - the generator still works perfectly.
What if a site doesn't allow special characters?
Increase the length to compensate. A 20-character password with just letters and numbers is more secure than a 12-character password with all character types. Use our Password Generator Pro to customize which characters are included.
Start Generating Secure Passwords Today
Use our cryptographically secure password generator to create unique, strong passwords for all your accounts.