Password Strength Checker
Assess password strength and get concrete improvements
What is Password Strength Checker?
This password strength checker estimates entropy from the character space and length, then applies penalties for common weak passwords, repeated characters, keyboard runs, and embedded years, producing a strength rating, an offline cracking time estimate, and specific suggestions. The analysis runs locally and your password is never uploaded.
How to use Password Strength Checker
- 1Enter the password you want to assess — click the eye icon to reveal it.
- 2Review the entropy and strength rating alongside the cracking time estimated at 10 billion guesses per second.
- 3Work through the suggestions one by one, adding length first since it helps the most.
Frequently asked questions
How much entropy is enough for a password?+
The usual thresholds are 60 bits for "adequate" and 80 bits for "strong". Aim for 80 bits or more on everyday accounts and 100 bits or more where money or administrative access is involved. The easiest way to reach 80 bits is to push the length past 16 characters and mix all four character classes.
How does this compare to zxcvbn?+
zxcvbn ships tens of thousands of dictionary entries and far richer pattern matching, so it is more accurate — at the cost of a large bundle. This tool uses a lightweight estimate: character-space entropy minus penalties for common weak patterns. The direction is the same, but it cannot flag things like a password built from your own personal details, so apply judgment too.
Is my password sent to a server?+
No. The scoring logic and the weak-password list both run inside the page. Your input never leaves the browser and is not written to local storage.
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