Password Generator

Customize your password length and character options

Password Length: 16 characters

Character Types

Uppercase Letters (A-Z)

Lowercase Letters (a-z)

Numbers (0-9)

Symbols (!@#$%^&*)

Avoid Ambiguous Characters (Il1O0)

Exclude Specific Characters (optional)

Generated Password

Your secure password and strength analysis

Password Strength: Very Strong

How It Works

Our password generator creates cryptographically secure random passwords using your browser's built-in security features. All generation happens locally on your device for maximum privacy.

Maximum Security

We use Window.crypto.getRandomValues() for true cryptographic randomness, suitable for banking and email passwords. No data is ever sent to external servers.

Privacy First

All password generation happens in your browser. Passwords never leave your device, aren't stored on our servers, and disappear when you close the page.

How the Password Generator Works

Character Pool Creation: The generator starts by building a pool of available characters based on your selected options: uppercase letters (A-Z), lowercase letters (a-z), numbers (0-9), and symbols (!@#$%^&*).
Character Exclusion: Any characters you've specified in the "exclude" field are removed from the character pool. If you've selected "Avoid Ambiguous Characters," similar-looking characters (I, l, 1, O, 0) are also removed.
Random Selection: Using cryptographically secure random number generation, the tool selects characters randomly from the remaining pool. Each character has an equal chance of being selected.
Password Assembly: Characters are combined in the selected order to create a password of your specified length. The generator ensures at least one character from each selected character type is included.
Strength Evaluation: The password is analyzed based on length, character variety, and randomness to calculate a strength score from 0 to 100.
Output Delivery: The final password is displayed with instant copy functionality, and you can generate additional variations as needed.

Password Security Formulas

Entropy Calculation

E = L × log₂(N)

E = Password entropy in bits, L = Password length in characters, N = Size of character pool (number of possible characters)

Character Pool Size

N = ΣCᵢ

C₁ = 26 (if uppercase letters selected), C₂ = 26 (if lowercase letters selected), C₃ = 10 (if numbers selected), C₄ = 10-32 (if symbols selected, varies by symbol set)

Time to Crack Estimation

T = (V^L) / (G × 10⁹)

T = Time in seconds, V = Character set size, L = Password length, G = Guesses per second (typically 1-10 billion for modern GPUs)

Step-by-Step Examples

Standard Secure Password

Requirements: 12 characters, all character types Character pool: 26 uppercase + 26 lowercase + 10 numbers + 10 symbols = 72 characters Entropy: 12 × log₂(72) ≈ 74 bits

Example: "K8#mQ2$pL9!x" Time to crack: 10¹⁵ years

Memorable Yet Secure

Requirements: 16 characters, avoid ambiguous, exclude similar Character pool: 72 - 5 ambiguous = 67 characters Process: System ensures no "I", "l", "1", "O", or "0" appear

Security: 67¹⁶ possibilities ≈ 10²⁹ combinations

Numeric PIN Alternative

Requirements: 8 characters, numbers only, exclude 0 and 1 Character pool: 8 numbers (2-9) Entropy: 8 × log₂(8) = 24 bits

Example: "73928465" Use case: Temporary codes or secondary authentication

Understanding Password Security

Creating strong passwords is essential for protecting your online accounts from unauthorized access. A password generator helps you create secure, random passwords that are difficult to guess or crack through brute-force attacks.

What Makes a Password Secure?

Password security depends on several factors:

Length: Longer passwords are exponentially harder to crack. Each additional character multiplies the possible combinations by the character set size. A 12-character password with mixed characters has over 70 bits of entropy, making it virtually uncrackable with current technology.
Complexity: Using multiple character types (uppercase, lowercase, numbers, symbols) increases the character pool size from 26 (lowercase only) to 72+ characters, dramatically increasing security.
Randomness: Truly random passwords are more secure than predictable patterns or dictionary words. Password generators use cryptographic randomness that's mathematically unpredictable.
Uniqueness: Never reuse passwords across different accounts. Each account should have its own unique password to prevent credential stuffing attacks.
Storage: Use a reputable password manager to store and organize your passwords securely. Never write passwords in unsecured locations.

Understanding Entropy and Crack Time

Password entropy measures unpredictability in bits. Higher entropy means more security:

40-59 bits: Weak - Can be cracked in hours to days
60-79 bits: Moderate - Secure for most personal accounts
80-99 bits: Strong - Suitable for banking and financial accounts
100+ bits: Very strong - Government/military grade security

The time to crack a password doubles with each additional bit of entropy. A 12-character mixed password with 74 bits of entropy would take billions of years to crack with current technology.

Practical Password Strategies

Example: Online Banking Password

Recommended Approach:

Length: 16+ characters
Character types: All four (uppercase, lowercase, numbers, symbols)
Entropy target: 80+ bits
Storage: Use a password manager
Special characters: Include at least 2 different symbol types

Generated Example: "H7$kP9!mQ2@xL5#r"

Security Analysis: This password would take centuries to crack with current computing power, making it suitable for protecting your financial accounts. The 16-character length with all character types provides approximately 95 bits of entropy.

Example: Social Media Account

Recommended Approach:

Length: 12+ characters
Character types: At least 3 different types
Entropy target: 70+ bits
Avoid: Personal information, dictionary words

Generated Example: "tR8#mK2$pQ9!x"

Security Analysis: While less critical than banking, social media accounts still need protection against credential stuffing and account takeover attacks. This 13-character password provides solid security for everyday use.

Password Rotation Best Practices

When and how to change your passwords:

Immediate change: After any data breach notification or suspected compromise
Regular rotation: Every 90 days for high-value accounts (email, banking)
Annual review: Check and update passwords for all accounts yearly
Use password managers: They can generate and store unique passwords for each site
Two-factor authentication: Always enable 2FA when available for added security

Common Password Mistakes to Avoid

Even with strong passwords, these mistakes can compromise security:

Password reuse: Using the same password across multiple sites
Predictable patterns: Sequential numbers (123), keyboard patterns (qwerty)
Personal information: Birthdates, names, pet names that are easy to guess
Short passwords: Anything under 8 characters is vulnerable to brute force
Storing in plain text: Writing passwords in unencrypted files or notes
Sharing passwords: Even with trusted individuals, it increases risk

Advanced Security Considerations

For maximum security, consider these additional measures:

Passphrases: Consider using 4-5 random words for accounts you need to memorize (e.g., "correct-horse-battery-staple")
Password manager integration: Many password managers have built-in generators that sync across devices
Security keys: For critical accounts, use hardware security keys (YubiKey, Titan) for 2FA
Regular audits: Use password checkers to identify weak or compromised passwords
Education: Train family or team members on password security best practices

Remember: No password is 100% uncrackable, but using our password generator with the recommendations above will make your passwords strong enough that the time and cost to crack them far exceeds the value of what they protect. Combine strong, unique passwords with two-factor authentication for the best protection against unauthorized access.

Frequently Asked Questions

How random are the generated passwords?

We use Window.crypto.getRandomValues() for cryptographically secure randomness, suitable for security applications. This method uses your system's entropy sources for true randomness, not predictable pseudo-random algorithms.

Are my generated passwords stored or transmitted?

No. All generation happens locally in your browser. Passwords never leave your device, aren't stored on our servers, and disappear from memory when you close the page. No network requests are made during password generation.

What makes a password "strong" versus "very strong"?

Strength depends on length and character variety. 12+ characters with all four character types typically rates "very strong." Each additional character exponentially increases security—adding one character multiplies the possible combinations by the character set size.

Why avoid ambiguous characters like "l" and "1"?

These characters cause confusion when manually entering passwords. Excluding them reduces user error while minimally affecting security—only 5 characters removed from a 72+ character pool. This is especially helpful for passwords you might need to type on mobile devices.

How often should I generate new passwords?

Generate new passwords immediately for any breached account. Otherwise, follow organizational policies—typically every 90 days for corporate accounts or when you suspect compromise. Don't reuse passwords across different accounts.

Can I use this for password manager master passwords?

Yes, but ensure it's at least 20 characters with all character types enabled. Write it down physically as a backup since password managers can't recover lost master passwords. Consider using a passphrase for easier memorization of master passwords.