Free Online Password Generator
Generate strong, secure passwords with custom length and character sets.
Character Types
What Makes a Password Strong?
Password strength is measured in entropy bits — a mathematical expression of unpredictability. Each bit doubles the number of guesses an attacker needs. At 80 bits, a password survives modern brute-force hardware for decades. At 128 bits, it is effectively uncrackable by any foreseeable technology. Two factors control entropy: length and character-set size.
How the Generator Works
Every password is generated using crypto.getRandomValues() — the same
cryptographically secure random number generator your browser uses for HTTPS connections.
To eliminate statistical bias, the tool uses rejection sampling: random bytes
that fall outside a range evenly divisible by the charset size are discarded, ensuring
every possible character is equally likely.
Nothing is sent over the network. The generator works entirely in JavaScript, even offline once the page has loaded.
Choosing Your Settings
- Length 12–16 — suitable for lower-risk accounts stored in a password manager.
- Length 20–32 — recommended for email, cloud storage, and financial accounts.
- Length 32–64 — ideal for master passwords, SSH keys, and API secrets.
- Include symbols unless a site explicitly forbids them — they add ~1.6 bits per character to entropy.
- All four types at length 20 gives ≈ 131 bits of entropy, which is excellent for any purpose.
Storing Your Passwords Safely
A strong password only protects you if it is stored securely. Use a reputable password manager — Bitwarden (free, open-source), 1Password, or Dashlane — to store unique passwords for every account. Never reuse passwords, never store them in plain-text files, and never rely on browser auto-save without a master password protecting the vault.
How to Use Password Generator
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1
Set password length
Drag the slider or type a number to set your password length. 16 characters is a solid minimum; use 20+ for email and banking accounts.
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2
Choose character types
Toggle uppercase letters, lowercase letters, numbers, and symbols on or off. At least two types must stay enabled.
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3
Regenerate until satisfied
Click the refresh icon or Regenerate button to create a new password with the same settings. Each click produces a cryptographically random result.
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4
Copy and save
Click Copy Password to copy it to your clipboard, then paste it directly into your password manager. Never store passwords in plain text.
Frequently Asked Questions
crypto.getRandomValues(), the same cryptographically strong random number generator used by browsers for TLS and security tokens. It employs rejection sampling to eliminate modulo bias, so every character in your charset has an exactly equal probability of being selected. No passwords are transmitted to any server.
entropy = length × log₂(charsetSize). For example, a 20-character password using all character types (95 chars) has 20 × 6.57 ≈ 131 bits of entropy.