Strong Password Generator
The strong password generator creates cryptographically secure passwords using your browser's random number source. Set length, choose character sets, uppercase, lowercase, numbers, symbols, and copy your password in one click. All generation runs client-side in your browser. No password you generate is sent to any server, logged, or stored anywhere.
How to use Strong Password Generator
- Set your desired password length using the slider (8 to 64 characters).
- Toggle the character sets you want: uppercase, lowercase, numbers, and symbols.
- Click Generate Password to create a cryptographically secure password.
- Check the strength indicator and entropy rating.
- Click Copy to copy the password to your clipboard.
What makes a password strong
A strong password has three properties: sufficient length, character variety, and unpredictability. Length is the most important factor. A 16-character password drawn from all character sets has 95^16 possible combinations, approximately 4.4 quadrillion possibilities, compared to 95^8 for an 8-character password, which has already been indexed in rainbow table databases used by attackers. Current security guidance from NIST recommends a minimum of 16 characters for new passwords on sensitive accounts.
Character variety forces attackers who do not have the exact password into either brute-force or dictionary attacks. Including symbols breaks dictionary attacks because no common word includes a symbol sequence. Including numbers in non-obvious positions, not just at the end, removes the predictable suffix pattern that attackers exploit when users add numbers to comply with requirements. A secure password generator that uses full character set diversity and cryptographic randomness produces passwords that defeat all known offline attack strategies at lengths above 12 characters.
How this password generator works
The generator builds a character pool from the sets you select: lowercase a-z, uppercase A-Z, digits 0-9, and symbols. It then calls crypto.getRandomValues() to generate a Uint32Array of random bytes equal to the password length you specify. Each byte is taken modulo the pool size to select one character. This method produces statistically uniform selection across all characters with no bias toward any particular character or position.
The 16 character password generator setting produces passwords with approximately 104 bits of entropy when using the full character set. The password strength indicator calculates entropy from the pool size and length and converts it to a practical rating. Entropy above 80 bits is considered strong for current threat models. The generator history displays your recent passwords within the current session, this history is stored in browser memory only and clears when you close or reload the tab.
Frequently asked questions
Passwords are generated using the browser's crypto.getRandomValues() API, which produces cryptographically uniform random values. At 16 characters with all character sets enabled, each password has approximately 104 bits of entropy, which is beyond the reach of all known offline brute-force attacks with current hardware. The generator produces no predictable patterns.
Three factors determine password strength: length, character variety, and unpredictability. Length has the largest impact, each additional character multiplies the number of possible passwords by the character set size. Character variety prevents dictionary attacks. Unpredictability, using a generator rather than a memorable phrase, prevents pattern-based attacks. A 16-character password from a full character set is considered strong for all practical purposes.
NIST guidelines recommend a minimum of 16 characters for new credentials on sensitive accounts. For most personal accounts, 12 characters with full character set diversity is acceptable. For master passwords protecting a password manager, 20 characters or more is recommended. This generator supports up to 64 characters for maximum-security use cases.
No. All password generation runs in your browser using local JavaScript. No generated password is transmitted to any server. The generator history shown on the page is stored in browser memory and clears when you close or reload the tab. There is no backend, no analytics on the passwords generated, and no way for the site operator to see any value you generate.