Password Strength Checker
Analyze password strength by checking length, character variety, and entropy.
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FAQ
- How is password strength calculated?
- Strength is determined by scoring several factors: length (longer is better), use of uppercase letters, lowercase letters, numbers, and special symbols. Each factor contributes to the score, which maps to weak, fair, good, or strong ratings.
- What is entropy and why does it matter?
- Entropy (measured in bits) represents the unpredictability of a password. It is calculated as log2(charset_size ^ length). Higher entropy means more possible combinations and a harder-to-crack password. 60+ bits is generally considered strong.
- Is my password sent to a server?
- No. The analysis runs entirely in your browser using JavaScript. Your password is never transmitted anywhere.
Evaluate how strong a password is by analyzing its length, use of uppercase and lowercase letters, numbers, and symbols, and estimated entropy in bits. Instantly see a strength rating (weak, fair, good, or strong), specific feedback on what to improve, and how much entropy the password contains. All analysis is local — your password is never sent anywhere.