—Entropy measures how many guesses, on average, it takes to hit the password — every bit doubles that number. Below 40 bits a password falls within hours, between 40 and 60 it holds for days, between 60 and 80 for years, and above 80 it is beyond the reach of today's hardware. The estimate assumes an offline attack at around 100 billion guesses per second, so it is deliberately pessimistic.
Already have a password? See how strong it is
How to use the tool
Choose a type
Random characters for maximum resistance, or a passphrase that is easy to type on a phone and to remember by heart.
Set the rules
Length, upper- and lowercase letters, digits and symbols. If needed, remove ambiguous characters (0/O, 1/l) or forbid repeats.
Check the strength and copy
The bar below the password shows its entropy in bits and how long it would take to crack. The Copy button puts it on your clipboard.
Frequently asked questions
No. It is generated on your device by the browser's cryptographic generator (crypto.getRandomValues) and is not sent anywhere — the page has no server to send it to.
For ordinary accounts, 16 characters is enough. For admin access, banking and hosting, go for 20 or more. Length matters more than exotic symbols.
Bits show how many guesses, on average, it takes to hit the password: each bit doubles that number. Below 40 bits a password falls quickly; above 80 bits it cannot be cracked with today's hardware.
It depends on how you use it. Random characters give more strength per character but are hard to type. A passphrase of 5–6 words is just as strong, yet much easier to type and remember — a good fit for passwords you enter often.
No. If one site leaks its data, the same password unlocks the others too. Generate a separate one for each login and keep them in a password manager.
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