Password Generator online

This tool uses the crypto.getRandomValues() Web Cryptography API, the same source of randomness used by cryptographic systems. Unlike Math.random() which uses a predictable pseudo-random algorithm, crypto.getRandomValues() provides true cryptographic randomness — making it suitable for generating secure passwords and tokens.

What Makes a Password Strong?

• Length — each additional character multiplies the search space exponentially
• Character diversity — using uppercase, lowercase, numbers, and symbols increases entropy
• True randomness — generated by a cryptographic random number generator, not a human
• Uniqueness — never reuse passwords across different accounts

How Does This Password Generator Work Online?

This tool generates cryptographically random passwords using the browser's crypto.getRandomValues() API — the same source of entropy used by security libraries and operating system random number generators. Unlike tools that use Math.random() (which is predictable and not suitable for security), every character in the generated password is chosen from a uniform, unbiased random distribution. Your passwords are generated entirely in your browser and are never transmitted to any server.

What Makes a Strong Password?

Password strength is measured in bits of entropy — a mathematical representation of how unpredictable the password is. The two biggest factors are:

• Length — the single most important factor. Every additional character multiplies the number of possible passwords exponentially. A 20-character password is astronomically harder to crack than a 10-character one, even if both use only lowercase letters.
• Character set size — lowercase only gives 26 options per character; adding uppercase brings it to 52; adding digits gives 62; adding symbols gives 94+. Larger character sets increase the entropy per character.
• Unpredictability — no dictionary words, names, dates, or keyboard walks (qwerty, 123456). Random character sequences are much harder to attack than mangled words.
• Uniqueness — every account should have a different password. Reusing passwords means a breach at one site exposes all your accounts.

Password Entropy by Length and Character Set

• 8 chars, lowercase only: ~37 bits — crackable in seconds with modern hardware
• 12 chars, mixed case + digits: ~71 bits — reasonable for low-risk accounts
• 16 chars, all characters: ~105 bits — strong; suitable for high-value accounts
• 24 chars, all characters: ~157 bits — extremely strong; use for master passwords

Should You Use a Password Manager?

Yes. Even the strongest generated password is useless if you write it on a sticky note or reuse it. A password manager (Bitwarden, 1Password, KeePassXC) stores your generated passwords securely, auto-fills them, and can itself generate strong passwords. Use this tool to generate a strong master password for your password manager, then let the manager handle everything else.