🔐

Password Generator

Generate secure passwords and analyze password strength

412128

Password Generator: Secure Random Password Creator

Table of Contents - Password Generator

How to Use This Generator - Password Generator

Select your Password Type:

  • Traditional (random characters)
  • Passphrase (random words)

For traditional passwords: Choose your desired Length (12-128 characters; 16+ recommended). Select character sets: uppercase letters, lowercase letters, numbers, and/or symbols.

For passphrases: Choose the number of words (4-10; 5+ recommended). Select a separator: hyphen, space, or none.

Click "Generate" to create a password. The output displays:

  • Your generated password
  • Entropy (strength) in bits
  • Copy button for clipboard

Generate multiple options until you find one suitable for your needs.

The Core Principle: Entropy and Randomness

Password strength comes from entropy—the measure of randomness or unpredictability. Higher entropy means more possible combinations an attacker must try.

Entropy is calculated as: Entropy (bits) = log₂(possible characters) × password length

A 94-character set (uppercase + lowercase + digits + symbols) with 16 characters: Entropy = log₂(94) × 16 = 6.55 × 16 = 105 bits

This means 2^105 possible combinations—far more than any computer could try.

Why randomness matters: Human-chosen passwords follow patterns (names, dates, dictionary words). These patterns dramatically reduce effective entropy. "Password123!" has low entropy despite meeting complexity requirements because it's predictable.

Cryptographically random generation eliminates patterns, maximizing entropy for any given length and character set.

How Password Strength Is Calculated

Traditional password entropy: Each character adds log₂(character set size) bits.

Character sets:

  • Lowercase only (26): 4.7 bits/character
  • Lowercase + uppercase (52): 5.7 bits/character
  • Alphanumeric (62): 5.95 bits/character
  • Full ASCII printable (94): 6.55 bits/character

Examples:

  • 8-character, lowercase only: 8 × 4.7 = 37.6 bits (weak)
  • 12-character, alphanumeric: 12 × 5.95 = 71.4 bits (acceptable)
  • 16-character, full set: 16 × 6.55 = 105 bits (strong)

Passphrase entropy: Each word adds log₂(dictionary size) bits.

With a 7,776-word list (diceware standard):

  • 4 words: 4 × 12.9 = 51.7 bits
  • 5 words: 5 × 12.9 = 64.6 bits
  • 6 words: 6 × 12.9 = 77.5 bits

Strength recommendations:

  • 64+ bits: Adequate for most online accounts
  • 80+ bits: Strong; suitable for important accounts
  • 128+ bits: Very strong; suitable for master passwords and encryption keys

Real-World Applications

Password manager master password. Use a 5-6 word passphrase—memorable but strong. This is the one password you must remember.

Individual website accounts. Generate unique 16+ character random passwords for each site. Store in your password manager.

WiFi network password. Generate a long, random password (20+ characters). You rarely need to type it manually.

API keys and service accounts. Maximum length random strings. No memorability needed; security is paramount.

Temporary or shared passwords. Generate, share securely, and plan to change after the temporary use ends.

Encryption keys. Maximum entropy needed. Use the longest, most random string the system accepts.

Scenarios People Actually Run Into

The website restriction. You generate a 24-character password with symbols, but the site limits to 16 characters and no symbols. Adjust settings and regenerate within the constraints—still maximize length.

The memorability challenge. Your password manager's master password needs to be remembered. A 5-word passphrase like "correct-horse-battery-staple" is both strong and memorable.

The mobile entry pain. Complex passwords are hard to type on phones. If you frequently enter manually, consider longer alphanumeric passwords over shorter symbol-heavy ones.

The "password123" recovery. You're updating an old, weak password. Generate a new one, update the account, and store in your password manager. Never reuse the old pattern.

The breach notification. A service you use reports a data breach. Generate a new password immediately for that service—and any others where you reused it.

Trade-Offs and Decisions People Underestimate

Length versus complexity. A 20-character lowercase password is stronger than a 10-character password with symbols. Length matters more than character set diversity.

Memorability versus security. For accounts accessed via password manager, maximum randomness is ideal. For master passwords, memorability matters—use passphrases.

Uniqueness versus convenience. Unique passwords for every account means managing hundreds of passwords. A password manager makes this practical.

Maximum versus required. Some sites have low maximum lengths. Use the maximum allowed, even if it seems arbitrary.

Regeneration versus reuse. If you suspect any exposure, regenerate. The cost of regeneration is minutes; the cost of breach can be catastrophic.

Common Mistakes and How to Recover

Reusing passwords. One breach exposes all accounts using that password. Generate unique passwords for every account; use a password manager.

Using predictable patterns. "Summer2024!" is not random. Use true random generation, not human patterns.

Ignoring password managers. Trying to remember dozens of unique, complex passwords leads to either reuse or weak passwords. Use a manager.

Trusting insecure generators. Only use generators that operate client-side (in your browser). Avoid any that email or store passwords.

Not enabling 2FA. Even perfect passwords can be phished. Enable two-factor authentication on all critical accounts.

Related Topics

Two-factor authentication (2FA). Something you know (password) plus something you have (phone, security key). Dramatically increases security.

Password managers. Software that generates, stores, and autofills passwords. Essential for managing unique passwords across many accounts.

Credential stuffing. Automated attacks using leaked username/password pairs from one breach against other sites. Unique passwords prevent this.

Entropy. The mathematical measure of randomness, expressed in bits. Higher entropy = more secure.

Diceware. A method for generating passphrases using dice rolls and word lists. Ensures true randomness even without electronic generation.

How This Generator Works

Cryptographic random generation: Uses the browser's crypto.getRandomValues() API for cryptographically secure randomness—not predictable pseudo-random sequences.

Traditional password generation:

characterPool = selected character sets combined
password = ''
for i in range(length):
  randomIndex = crypto.getRandomValues() % characterPool.length
  password += characterPool[randomIndex]

Passphrase generation:

wordList = curated list of common words
passphrase = []
for i in range(wordCount):
  randomIndex = crypto.getRandomValues() % wordList.length
  passphrase.append(wordList[randomIndex])
result = passphrase.join(separator)

Entropy calculation:

Traditional: log2(characterPoolSize) × length
Passphrase: log2(wordListSize) × wordCount

All generation happens locally in your browser—no data is transmitted.

FAQs

Is this generator safe to use?

Yes. All passwords are created locally in your browser using cryptographically secure randomness. No data is sent to any server.

What is entropy, and why does it matter?

Entropy measures password strength in bits. Each bit doubles the number of guesses needed. 80+ bits is considered strong against current attacks.

Should I use a passphrase or random password?

Passphrase for your master password (memorable, strong). Random passwords for everything else (maximum entropy, stored in manager).

What if a website has password rules?

Adjust generator settings to meet requirements while maximizing allowed length and character variety.

Do I really need a password manager?

Yes. Managing unique, complex passwords for dozens of accounts is impossible without one. Password managers make strong security practical.

How often should I change passwords?

Only when compromised, exposed, or required by policy. Routine rotation without cause can lead to weaker passwords.

Can I trust online password generators?

Only if they're client-side (all generation in your browser). Verify by checking that the page works offline.

What makes a password "strong enough"?

64+ bits of entropy for typical accounts, 80+ for important accounts, 128+ for master passwords and encryption keys.

How do password attacks work?

Brute force tries every combination. Dictionary attacks try common words and patterns. Credential stuffing uses leaked passwords from other sites. Random generation defeats all these approaches.

What's the difference between hashing and encryption?

Hashing is one-way—passwords are hashed for storage and can't be recovered. Encryption is two-way—data can be encrypted and decrypted with a key. Passwords should be hashed, not encrypted, by services.

How do I securely share a password?

Never via email or text. Use a password manager's secure sharing feature, an encrypted messaging app, or a one-time secret service that expires after viewing.

What is multi-factor authentication?

Something you know (password) plus something you have (phone, security key) or something you are (biometric). Even perfect passwords can be phished; MFA adds another layer.

Are biometrics better than passwords?

Biometrics are convenient but can't be changed if compromised. Use biometrics as a second factor with a strong password, not as a replacement.

What should I do after a data breach?

Change the password for the affected site immediately. Check if you reused that password elsewhere and change those too. Consider credit monitoring if financial data was exposed.

How do password managers get hacked?

Rarely, and usually through user error (weak master password, phishing). Major password managers use zero-knowledge encryption—even if their servers are breached, encrypted vaults remain secure.

What's the future of passwords?

Passwordless authentication using security keys, biometrics, and passkeys is growing. Until fully adopted, strong unique passwords remain essential. Consider hardware security keys for important accounts.

How do I audit my existing passwords?

Most password managers include security audits. They identify weak, reused, or compromised passwords. Systematically update the worst offenders.

Should I use a browser's built-in password manager?

It's better than reusing passwords, but dedicated password managers offer more features: cross-platform sync, secure sharing, emergency access, and better security auditing.

How long would it take to crack my password?

A 12-character random password with mixed characters would take millions of years with current technology. An 8-character dictionary word can be cracked in seconds. Length and randomness are everything.

What about quantum computing and passwords?

Quantum computers could theoretically crack current encryption, but this threat is years away. When it materializes, cryptography will adapt. Current strong passwords remain secure for the foreseeable future.

How do I create a memorable master password?

Use a passphrase of 5-6 random words. Create a mental story linking them. "purple-elephant-dancing-Tuesday-kitchen" is both memorable and strong.

Should I write down my passwords?

For your master password, a written backup stored securely (safe, safety deposit box) is acceptable. For other passwords, rely on your password manager—that's its purpose.

What's the deal with security questions?

Treat security questions as secondary passwords. Generate random answers and store them in your password manager. Real answers (mother's maiden name) are often easy to research.

Additional Notes

Password security is the foundation of digital safety. Invest time in proper password hygiene—unique, random passwords for every account, managed by a trusted password manager. Strong passwords combined with two-factor authentication provide robust protection against the most common attack vectors in today's digital landscape. Your digital security is worth the small investment of time to implement proper password practices across all your accounts. Make it a habit to generate new unique passwords for every new account you create, no exceptions. The few minutes spent today on password security prevents hours of recovery work after a breach.