Password Generator Online — Create Strong Random Passwords Free

What Makes a Password Strong?

Password strength is measured by entropy — the number of possible combinations an attacker must try to guess the password by brute force. Entropy increases with both length and character set size. A 12-character password using only lowercase letters has 26¹² ≈ 95 billion possible combinations. Adding uppercase, digits, and symbols expands the character set to ~95 characters, raising the same 12-character password to 95¹² ≈ 540 quintillion possibilities.

Length matters more than complexity. A 20-character password using only lowercase letters is harder to crack than a 10-character password with symbols. Most security guidance now recommends length first: aim for at least 16 characters for important accounts, and use a password manager to store them.

Password Strength by Length and Character Set

How to Use the Password Generator

1. Set the length. Use the slider or input to choose the password length. 16 characters is a sensible minimum for most accounts; 20+ for financial, email, and admin accounts.
2. Choose character sets. Toggle uppercase letters (A–Z), lowercase letters (a–z), numbers (0–9), and special symbols (!@#$%^&*…). Include all four for maximum strength unless the service has restrictions.
3. Generate. Click Generate to create a new random password. Click again to regenerate a different one.
4. Copy and save. Copy the password and immediately save it in your password manager. Do not type it into a document or email — use the copy button and paste directly.

Password Security Best Practices

Use a unique password for every account

Password reuse is the most common way accounts get compromised. When a service is breached and its password database is leaked, attackers test those credentials on hundreds of other services (credential stuffing). A single reused password can cascade into a full identity compromise. Using a unique generated password for every account limits damage to a single service.

Use a password manager

You cannot memorise 50 unique 20-character passwords. Password managers (Bitwarden, 1Password, Dashlane, KeePass) generate, store, and autofill passwords securely. Your master password — the one that unlocks the manager — should be a memorable passphrase of 4–6 random words rather than a complex string. Most password managers also include their own generators. Use the password strength checker to verify how strong your current passwords are.

Enable two-factor authentication

Even a strong password can be phished or stolen in a data breach. Two-factor authentication (2FA) adds a second verification step — a one-time code from an authenticator app or hardware key — that an attacker cannot use without physical access to your device. Enable 2FA on every account that supports it, prioritising email, financial accounts, and any account that acts as a recovery method for others.

Common Questions

Is it safe to generate passwords in a browser?

This generator uses the Web Cryptography API (window.crypto.getRandomValues()) to generate cryptographically secure random values. The password is generated locally in your browser and is never transmitted to a server. It is safe to use on a trusted device on a trusted network.

Should I avoid certain characters?

Some websites and applications reject certain special characters in passwords — particularly quotes (' "), backslashes (\), and angle brackets (< >). If a generated password is rejected at signup, regenerate without symbols or toggle only a safe subset of symbol characters (such as !@#$%^&*).

How often should I change my password?

Current security guidance (NIST SP 800-63B) recommends against routine periodic password changes unless there is evidence of compromise. Changing passwords on a schedule leads people to make small predictable variations (password1 → password2), which is less secure than keeping a strong unique password indefinitely. Change a password when: you suspect it has been compromised, the service reports a breach, you have shared it with someone, or you have been using the same password for years across many accounts.