Password Generator
Generate strong, truly random passwords with this free password generator. Pick a length and character sets, get a new password instantly, and see its entropy rating — everything runs fully offline in your browser, nothing is ever sent anywhere.
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Your results
Generated with crypto.getRandomValues on your device (Math.random fallback on older browsers). Runs fully offline — no password is ever sent or stored anywhere.
How to use this calculator
Drag the length slider, tick the character sets you want, and a new password appears instantly — every change regenerates it. Press Generate for a fresh one, then Copy to put it on your clipboard.
Example: 16 characters with all four sets gives a pool of 94 characters, so entropy = 16 × log₂(94) ≈ 104.9 bits — rated Very strong.
How it works
Entropy = length × log₂(character pool size), in bits. Strength bands: under 40 bits Weak, 40–60 Fair, 60–80 Strong, 80+ Very strong. A 94-character pool comes from 26 uppercase + 26 lowercase + 10 digits + 32 symbols; excluding ambiguous characters (I, l, 1, O, 0) drops it to 89.
Randomness comes from your browser's cryptographic generator (crypto.getRandomValues), which draws from the operating system's entropy source — not a predictable pseudo-random sequence. Math.random is only used as a fallback on browsers without it, and that's noted in the results.
Frequently asked questions
Is this password generator safe to use?
Yes. It runs entirely offline in your browser using your device's cryptographic random number generator (crypto.getRandomValues). Your passwords are never sent to any server, and the page works with no network connection at all.
What does password entropy mean?
Entropy in bits measures how many guesses an attacker would need to crack the password: entropy = length x log2(character pool size). A 16-character password from all 94 printable characters has about 104.9 bits of entropy - far beyond what brute force can reach.
How long should a strong password be?
Use at least 16 characters with all character sets for important accounts - that scores 80+ bits (Very strong) in this calculator. For anything you must memorize, a long passphrase of random words is a practical alternative.
What are ambiguous characters?
Characters that look alike in many fonts: capital I, lowercase l, the digit 1, capital O, and the digit 0. The exclude-ambiguous option removes them so passwords are easier to read and retype correctly.