Password Strength Checker

Analyze your password's strength, entropy, and estimated crack time. 100% client-side — nothing is sent to any server.

Password

Requirements

12+ characters

Uppercase (A-Z)

Lowercase (a-z)

Numbers (0-9)

Special chars (!@#)

Not common

No repeats (aaa)

Generator

Length16

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Password Strength

Enter a Password

Type above to begin

Crack Time

—

Entropy

0.0 bits

Length

0chars

Unique Chars

Char Types

0of 4

Documentation

How It Works

We calculate entropy (randomness) based on character types and length. Higher entropy means more possible combinations, making the password harder to crack.

Your password never leaves your browser. All analysis is done client-side.

Password Best Practices

Use a unique password for every account.
Use a password manager to store them safely.
Enable two-factor authentication (2FA) whenever possible.
Passphrases (e.g., "correct-horse-battery-staple") are both strong and memorable.

Entropy Formula

H = Entropy (bits), L = Password length, N = Charset size

Frequently Asked Questions