Question 1

How does the password strength checker work?

Accepted Answer

NexTool's password strength checker calculates entropy based on character pool size and password length. It also checks for common passwords, repeated characters, sequential patterns, and dictionary words. The estimated crack time assumes 10 billion guesses per second.

Question 2

Is it safe to enter my password in this tool?

Accepted Answer

Yes. NexTool's password strength checker runs 100% in your browser using JavaScript. No data is sent to any server. Your password never leaves your device. You can verify this by using the tool offline.

Question 3

What makes a strong password?

Accepted Answer

A strong password is at least 12 characters long, uses a mix of uppercase letters, lowercase letters, numbers, and symbols, avoids dictionary words and common patterns, and is unique for each account.

Question 4

What is password entropy?

Accepted Answer

Password entropy measures the unpredictability of a password in bits. It's calculated as length multiplied by log2(character pool size). Higher entropy means more possible combinations and a harder-to-crack password. 60+ bits is considered strong.

Question 5

How accurate is the crack time estimate?

Accepted Answer

The crack time estimate assumes a brute-force attack at 10 billion guesses per second (typical of modern GPU clusters). Real-world attacks may be faster with dictionary attacks or slower without specialized hardware. Use it as a relative guide, not an absolute measure.

Free Password Strength Checker

Tips for stronger passwords

Need something more powerful?

NexTool on GitHub