Password Generator
Generate strong, random passwords with customizable length and character sets.
A password's real strength comes almost entirely from how much randomness (entropy) it contains, not from following intuitive-seeming rules like substituting '@' for 'a'. A 16-character password drawn from a large random character set can take longer to brute-force than a lifetime of computing, while a predictable pattern-based password can fall in seconds no matter how long it looks.
This generator produces passwords using the Web Crypto API's crypto.getRandomValues(), a cryptographically secure random number generator, rather than JavaScript's Math.random() which is not designed for security purposes and can be predictable. You control the length and which character sets are included (uppercase, lowercase, numbers, symbols), plus an option to exclude visually ambiguous characters like I, l, 1, O, and 0 — useful when a password needs to be read aloud or typed from a printed copy.
An entropy estimate is shown alongside the generated password, calculated as length × log2(character set size), which tells you roughly how many attempts a brute-force attack would need. As a rough guide, 40 bits is weak, 60-80 bits is reasonable for most accounts, and 100+ bits is effectively uncrackable with current technology.
How to use Password Generator
- 1
Adjust the length
Use the slider to set your desired password length, from 4 to 64 characters.
- 2
Choose character sets
Toggle uppercase, lowercase, numbers, and symbols on or off depending on the target system's requirements.
- 3
Regenerate as needed
Click Regenerate for a fresh password using the same settings.
- 4
Copy and store it safely
Copy the password directly into a password manager rather than a plain text file or note.
Features
- Cryptographically secure randomness via the Web Crypto API
- Adjustable length from 4 to 64 characters
- Toggle uppercase, lowercase, numbers, and symbols independently
- Optional exclusion of visually ambiguous characters
- Live entropy estimate with a strength rating
Frequently asked questions
Common mistakes to avoid
- Reusing the same strong password across multiple accounts.
- Choosing a shorter password with symbols over a longer password without them — length matters more than character variety once you're past a minimal set.
- Storing generated passwords in an unencrypted note or spreadsheet instead of a password manager.
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