Password Generator
A free, browser-based calculator. Runs entirely in your browser — no sign up, nothing stored.
Generated with your browser's secure random generator. Nothing is sent or stored — refresh and it's gone.
How to use this calculator
- Set the length and tick the character types you want.
- Press the refresh button for a new password, then Copy. Optionally exclude look-alike characters.
How it works
Each character is drawn from your chosen set using the browser's cryptographically-secure random generator (with bias-free sampling).
The strength estimate is the Shannon entropy: log₂(character-set size) × length, in bits — more length and more character types mean a stronger password.
Worked example
16 chars, all types. ≈ 105 bits of entropy — very strong.
Common mistakes
- Going too short — under about 12 characters is easy to brute-force; longer is the single biggest win.
- Reusing one password everywhere — generate a unique one per site and store them in a password manager.
Frequently asked questions
Is this safe — are passwords sent anywhere?
No. Generation happens entirely in your browser using crypto.getRandomValues; nothing is transmitted or stored. Refresh the page and it's gone.
How long should my password be?
Aim for at least 12–16 characters with a mix of types. Longer is stronger; a passphrase of several random words is a good alternative.
Related tools
Tip: Enter any known values to calculate the remaining results.
All calculations run in your browser. Your inputs are never saved or transmitted.