Password Strength Checker Guide: Understanding Entropy and Why Your Password Might Be Weaker Than You Think

Most people think a password like P@ssw0rd! is strong because it contains symbols and numbers. In reality, modern hacking software can crack that password in less than a second because it follows a common substitution pattern that hackers have long since memorized.

Understanding Entropy

Entropy is a measure of randomness—the more random a password is, the higher its entropy, and the harder it is for a computer to guess. Our tool checks for unpredictability, not just special characters. A truly random 12-character password has more entropy than a predictable 20-character one.

The Time to Crack Estimate

We show you how long it would take a modern computer running a brute-force attack to guess your password. Weak passwords crack in milliseconds. Medium passwords might last days. Strong passwords would take centuries or millennia.

100% Local Analysis

Your password is analyzed entirely in your browser's JavaScript engine. It is never transmitted to our servers, never logged, and never stored. This makes our checker the safest way to audit your password security online.