Password Strength Tester

About Password Strength

This tool estimates password strength by computing approximate entropy in bits. Entropy increases with the logarithm of the search space: H ≈ n × log2(S), where n is the length and S is the character set size used. Longer, truly random passwords from a generator provide significantly more resistance to brute-force attacks than short or patterned strings. Online attack rates are constrained by throttling and MFA, but offline attacks against leaked password hashes can be millions to billions of guesses per second depending on the hash function and hardware. Favor length (12–16+) and randomness over simple substitutions (e.g., "P@ssw0rd!") which are modeled in modern cracking tools. Avoid dictionary words and predictable patterns; consider using a password manager to create and store unique credentials per site.

Improve workflow with our Password Generator. For general calculations, explore the Unit Converter; for personal metrics, see the BMI Calculator. All tools run client-side to protect your input data.