Home About Start Here Book Tools Resources Ask about PROFESSIONAL SERVICES

Password & Keys

Password Entropy Calculator

Estimate how resistant a password might be to brute-force guessing by looking at its entropy and approximate crack times.

All processing happens in your browser. This is a rough model for educational use, not a guarantee of security.

Input

Longer, more random passwords with a bigger character set have higher entropy.

Assumed attack speeds

Offline fast: 10¹⁰ guesses/sec. Online throttled: 10⁴ guesses/sec.

Entropy is estimated from password length and detected character sets (lowercase, uppercase, digits, symbols). Actual security also depends on reuse, storage, and attacker knowledge.

Results

Use this as a rough sense-check of password strength, not an excuse to skip MFA.

Entropy & character set

Length:
Estimated character set size:
Entropy: bits
Rating:

Rough time-to-crack

Offline fast (10¹⁰ guesses/sec):
Online throttled (10⁴ guesses/sec):

Quick examples

© 2025 Ask AppSec.