Password Strength Tester

Checking whether a password is good enough before you rely on it: sanity-check a password for an important account, compare a few candidates to see which is strongest, or learn what makes a password weak so you can improve it.

No. The analysis runs entirely in your browser. What you type is never uploaded, logged, stored, or transmitted — you can test even while offline.

It estimates entropy in bits from the length and the size of the character set used (lowercase, uppercase, digits, symbols), then converts that into an approximate time to crack. It also flags common weaknesses such as short length, a single character type, repeated characters and well-known passwords.

As a rule of thumb: under 40 bits is weak, 40–60 is fair, 60–80 is strong, and 80+ is very strong. For important accounts aim for 60 bits or more — roughly a 12+ character password that mixes character types.

It is a guide, not a guarantee. It assumes fast offline guessing (billions of attempts per second) against a password chosen randomly from its character set. A predictable password (a dictionary word, a name, a date) can be cracked far faster than its raw entropy suggests, which is why the warnings matter.

Length helps only when combined with unpredictability. A long password made of a single character type, repeated characters, or a common phrase has less real-world strength than its length implies.

Make it longer, mix in uppercase, numbers and symbols, and avoid dictionary words or personal information. The companion Password Generator can create a strong random password for you.