Password Strength Checker
Check how strong a password is, with an estimated entropy in bits and a 0-4 strength score. Free and private, entirely in your browser. Nothing is sent anywhere.
Type or paste a password to get an instant strength score, an estimate of how long it would take to crack, and specific reasons it's weak (common word, repeated pattern, not enough variety), useful when you're setting a new account password or auditing one you already use.
How to use it
- Type or paste the password into the field
- Read the strength score and the reasons behind it
- Adjust the password until it clears the weak spots flagged
Frequently asked questions
- Does my password get sent anywhere?
- No. The check runs entirely in your browser's JavaScript. Your password is never transmitted, logged, or stored, even if you're on a public Wi-Fi network.
- What makes a password 'strong' here?
- The checker looks past raw length and character variety to catch the things attackers actually exploit: dictionary words, keyboard patterns like 'qwerty' or '12345', repeated characters, and common substitutions (like '@' for 'a').
- Why did a long password still score low?
- Length alone doesn't beat pattern-based cracking. A 16-character password like 'passwordpassword123' is still weak because it's predictable. The score weighs predictability, not just character count.
- 1
Nothing is uploaded
The file never leaves your device. There is no server to send it to, so there is nothing to leak, log, or subpoena.
- 2
No signup, no limits
No account, no email, no daily cap, no watermark, and no paid tier waiting behind the third file.
- 3
Works offline
Load the page once and it keeps working with the network off, because all the work was always happening locally.