How is strength measured?

By entropy: the size of the character pool raised to the password length, translated into a crack-time estimate for common attack speeds.

What makes a password strong?

Length matters most. A long passphrase of random words beats a short complex password, and unique passwords per site matter more than anything.

Password Strength Checker

Test password strength with entropy scoring

Password to check

StrengthEnter a password

characters

charset size

0.0

entropy bits

Estimated time to crack (rough estimate)

…

Assumes an offline attack trying 10 billion guesses per second. Real attacks vary widely, so treat this as a rough estimate, not a guarantee.

Your password is checked only in your browser. It is never sent to any server, stored, or logged anywhere.

About this tool

Most password advice is vague. This checker gives you a concrete entropy score and an estimated crack time, so you can see exactly how much stronger adding four characters makes your password.

Because the analysis runs 100% locally, you can safely test real passwords you actually use, something you should never do on a server-side checker. Pair it with the password generator to create strong replacements.