Password Generator

Create strong, secure, and random passwords instantly

Password Strength --
Very Weak Weak Good Strong Very Strong
4 16 32 48 64

Advanced Options

Entropy: -- bits

Character Pool: -- characters

How to Use This Password Generator

  1. Adjust the password length slider (16+ characters recommended for most accounts)
  2. Select character types to include (uppercase, lowercase, numbers, symbols)
  3. Enable advanced options if needed (exclude ambiguous characters, no repeats)
  4. Click 'Generate Password' to create a new random password
  5. Click 'Copy' to copy the password to your clipboard

Example: A 16-character password with all character types enabled generates something like 'K9#mPx$2nQw@7LfB' with 105 bits of entropy - strong enough for banking and email accounts.

Tip: For passwords you'll type manually (like your computer login), consider excluding ambiguous characters (l, 1, I, O, 0) to avoid confusion.

Why Use a Password Generator?

Strong, unique passwords are your primary defense against account breaches. This generator creates truly random passwords that resist both guessing and brute-force attacks.

  • Generate unique passwords for each online account (never reuse passwords)
  • Create strong master passwords for password managers (20+ characters)
  • Generate secure Wi-Fi network passwords (WPA2 supports up to 63 characters)
  • Create API keys and tokens for development projects
  • Generate secure encryption passphrases for file protection
  • Replace weak passwords flagged in security audits

Understanding Your Results

Password strength is measured in entropy bits - higher is better.

Below 36 bits

Meaning: Very Weak - crackable in seconds

Action: Never use for any account - add length and character types

36-48 bits

Meaning: Weak - crackable in hours/days

Action: Only for throwaway accounts with no personal data

48-60 bits

Meaning: Good - would take months to crack

Action: Acceptable for low-importance accounts

60-120 bits

Meaning: Strong - would take centuries

Action: Recommended for email, banking, social media

Above 120 bits

Meaning: Very Strong - effectively uncrackable

Action: Ideal for password manager master passwords and encryption keys

Note: These estimates assume attackers can try billions of passwords per second. Actual security also depends on the service's security measures.

About Password Generator

This generator uses the Web Crypto API's cryptographically secure random number generator, which draws from your system's entropy sources (hardware events, timing variations, etc.) to produce unpredictable output. Unlike Math.random(), which uses a deterministic algorithm that could theoretically be predicted, crypto.getRandomValues() provides randomness suitable for security applications. The entire generation process happens in your browser - no passwords are ever transmitted or stored. For general-purpose random values in games or simulations, our roll virtual dice offers a fun alternative. To understand the probability behind password strength calculations, explore our probability calculator.

Formula

Entropy = log2(pool_size^length)

Pool size is the number of possible characters (94 with all types enabled). A 16-character password from 94 characters has log2(94^16) = 105 bits of entropy, meaning 2^105 possible combinations.

Current Standards: NIST SP 800-63B recommends passwords be at least 8 characters, but security experts suggest 12-16+ characters. Most importantly, each account should have a unique password stored in a password manager.

Frequently Asked Questions

Is it safe to generate passwords in a web browser?

Yes, when using a reputable tool like this one that generates passwords locally using the Web Crypto API. The password never leaves your browser - check the network tab in developer tools to verify. However, for maximum security (like password manager master passwords), consider using your password manager's built-in generator.

Should I use all character types?

Generally yes - more character types increase the pool size and entropy. However, some sites have poor password policies that reject certain symbols. If a site rejects your password, try disabling symbols or use only common ones (!@#$%^&*). Length matters more than complexity anyway.

How do I remember a random password?

Don't try to memorize random passwords - that's what password managers are for. Use a password manager to store all your unique passwords, then only memorize one strong master password. Popular options include Bitwarden, 1Password, and KeePassXC.

What length should I use for different accounts?

Use at least 12 characters for any account. For banking and email (which can reset other passwords), use 16+. For your password manager master password, use 20+ characters or a long passphrase. For WiFi passwords, 20+ characters since they're rarely typed manually.

Are passphrases better than random passwords?

Passphrases (like 'correct-horse-battery-staple') are easier to memorize but need to be longer for equivalent security. A 4-word passphrase from a 7,776-word list has about 51 bits of entropy - you'd need 5-6 random words to match a 16-character random password. For your master password, a memorable passphrase plus some random characters works well.

Developed by CalculatorOwl
View our methodology

Last updated: