Password
generator
A strong password is just enough randomness. Generate one locally, it never touches a network, with the honest math on how strong it actually is.
Prefer a physical calculator?
A few solid picks. As an Amazon Associate, Calculate.to earns from qualifying purchases, at no extra cost to you.
OSALO Desktop Calculator
Extra-large 12-digit LCD, giant buttons, solar + battery, the classic office desk workhorse.
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Helix Oxford Scientific
240-function scientific calculator for KS3–KS4 maths, with hard cover. Exam-friendly, plastic-free packaging.
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Casio fx-83GTCW+
The UK classroom-standard scientific calculator (also in pink), allowed in most UK exams.
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ROATEE Construction Calc
Feet-inch-fraction engineering calculator for carpenters, framers and contractors on site.
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Strength is just entropy
A password's strength is measured in bits of entropy: length times the log of the character pool. Each extra character multiplies the search space by the whole pool, which is why length beats cleverness every time.
Under ~60 bits: vulnerable to serious offline attacks
Every +1 character ≈ 6 more bits ≈ 75× harder
Generated locally, honestly
The password is built in your browser from cryptographic randomness and never transmitted, this page has no network calls, no storage, no history. At least one character from each class you enable is guaranteed (then the whole thing is re-shuffled so the guarantee adds no pattern). The crack estimate assumes a strong offline attacker at 10 billion guesses per second; online login attacks are millions of times slower.
The two rules that matter more than any generator
One: never reuse a password, breaches are cracked in bulk, and reuse turns one leak into every account. Two: use a password manager, so every login can be a unique 20-character string you never memorize. A generator like this is for the handful of passwords you must type by hand, device logins, the manager's own master password.
Password FAQ
Aim for roughly 80+ bits of entropy, about 14+ characters from a full mixed pool. This generator shows the exact bits and an honest crack-time estimate as you adjust length and options.
Here, yes, generation runs entirely in your browser with cryptographic randomness, and nothing is transmitted, stored or logged. You can verify by loading the page and disconnecting from the internet: it still works.
Both work when long enough. Random strings pack more entropy per character (best inside a password manager); four-plus random-word passphrases are easier to type and memorize for the few passwords you enter by hand.
Entropy scales linearly with length but only logarithmically with pool size: adding 13 symbols to the pool is worth about half a character of length. Sixteen simple characters beat ten exotic ones.