Password Generator

What this calculator does

The Password Generator creates a random password from the character types you select. You can choose the length and include lowercase letters, uppercase letters, numbers, and symbols. Generation happens locally in your browser.

How to use this calculator

1. Choose a password length between 4 and 128 characters.
2. Select at least one character type.
3. Click Calculate.
4. Use the Copy button to copy the generated password.

Formula

Entropy (bits) = password length × log2(size of the character pool)

The generator reserves at least one character from every selected character type, fills the remaining positions from the combined pool, and shuffles the result.

What the results mean

The default password is 16 characters and uses lowercase letters, uppercase letters, numbers, and symbols. Longer passwords and larger character pools produce higher entropy, which generally makes guessing harder.

Assumptions and limitations

• The password is generated in your browser with the Web Crypto API when available.
• This page does not store or transmit the generated password.
• Entropy is an estimate, not a guarantee that a password is safe for every threat model.
• Always use a password manager and a unique password for each account.

Frequently asked questions

Is the password sent to a server?

No. The password is generated in your browser. If your browser does not support the Web Crypto API, the page falls back to Math.random.

What length should I use?

Sixteen characters is a reasonable default for most accounts. Longer passwords are better for high-value accounts or where a service limits the character set.

Should I reuse a generated password?

No. Use a different password for every account and store it in a password manager.

Source

Reference: Password Generator.