Free interactive tool
Password Strength Visualizer
See how length and variety multiply cracking time — without typing a real password.
Watch a password get expensive to guess
Add length and character variety; the crack-time estimate does the arguing for you.
The model assumes an offline attacker guessing ten billion passwords per second. Length wins because every added character multiplies the whole search space.
- Compare 8 characters using everything against 16 lowercase letters.
- Find the shortest setting that survives for a century.
This tool never asks for a real password. You choose a length and which character sets it uses; the entropy — length × log₂(pool size) — and a crack-time estimate at ten billion guesses per second follow.
The hangout it teaches fast: length beats cleverness. Sixteen lowercase letters outlast eight characters of aggressive symbol soup.
How long should a password be?
14+ characters for anything important. Every added character multiplies the whole search space.
Why is entropy measured in bits?
Each bit doubles the guesses required; 60+ bits is a reasonable floor against offline attacks.