> entropy --calc "myP@ssw0rd123!"
What is Entropy?
Entropy is a measure of how unpredictable a password is. Higher entropy means more possible
combinations, making it harder for attackers to guess or brute-force your password.
Each added character increases the total entropy depending on the character set used (e.g. lowercase, digits, symbols).
For example, an 8-character password using lowercase letters only (26^8) has 37 bits of entropy, while using full charset can reach 52+ bits.
A strong password doesn’t need to be complicated, just smart. Use at least 12 characters. Mix uppercase and lowercase letters, numbers, and special symbols. Avoid real words, names, or anything someone could guess—like your pet’s name or “123456.” Longer is always better. And most importantly: don’t reuse the same password on multiple sites. If remembering them all feels impossible, use a trusted password manager to keep things safe and simple.
Disclaimer
The entropy values shown here are estimates based on character sets and length. They’re meant for educational and illustrative purposes only—not for certifying password security. Real-world safety depends on context, usage, and human behavior.
Note: This page does not log or send any passwords anywhere. Everything stays local in your browser. Still, for your own safety, please avoid entering passwords you actually use.