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Password Generator

Your password

Generated with crypto.getRandomValues in your browser. Nothing leaves this page.

Password entropy
bits = length × log₂(alphabet size) · each +1 bit doubles the cracking work

A strong password is just enough randomness — and randomness is measurable. This generator runs entirely in your browser on crypto.getRandomValues, the same cryptographic source your bank's login page uses, and reports the entropy honestly.

Why "generated locally" matters

A password that has ever crossed the network is a password with a history. Here, nothing is transmitted, stored or logged — the page even works offline (try airplane mode). The randomness uses rejection sampling for perfectly uniform character selection; no modulo bias, no Math.random().

Entropy: the only strength number that matters

Sixteen characters over the full 94-symbol set is 16 × 6.55 ≈ 105 bits — a search space no earthly hardware exhausts. The meter tiers are honest: below 50 bits is weak against offline cracking, 80+ is strong, 110+ is excellent. Length beats cleverness: adding 4 characters helps more than any symbol sprinkled into a short password.

Practical toggles

The exclude 0O1lI option removes lookalike characters for passwords a human might read aloud or retype — WiFi keys, one-time shares — at a negligible entropy cost. At least one character class always stays on, and every option change regenerates immediately so a stale password never lingers on screen.

Passwords vs passphrases vs managers

The real modern answer: a password manager storing unique 20+ character random strings, with a memorable passphrase guarding the vault itself. NIST's current guidance drops calendar-forced rotation — uniqueness per site and breach response beat ritual changes. For random numbers rather than strings, the random number generator uses the same crypto source.

All generation local; this site never sees your passwords.

Frequently Asked Questions

Is this password generator safe to use? +

Passwords are generated entirely in your browser with crypto.getRandomValues — nothing is sent, stored or logged anywhere. This page even works offline.

How long should a password be? +

16+ characters for anything that matters. Each added character multiplies the search space; a 16-character mixed password carries ~100 bits of entropy — far beyond practical brute force.

What is password entropy? +

The size of the search space, in bits: entropy = length × log₂(alphabet size). A 12-char password over 94 symbols is 12 × 6.55 ≈ 79 bits. Each extra bit doubles an attacker’s work.

Should I exclude ambiguous characters? +

If you might ever read or type the password manually, yes — 0/O and 1/l/I cause most transcription errors. The entropy cost of removing them is negligible.

Are passphrases better than random passwords? +

Four to five random dictionary words (~50–65 bits) are easier to memorize at similar strength. For passwords stored in a manager, random characters win — you never type them anyway.

How often should I change passwords? +

Modern guidance (NIST): change on evidence of compromise, not on a calendar. Unique-per-site matters vastly more than rotation — one breach must not unlock other accounts.

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