Password Strength Checker
Check how strong a password is. Instant feedback on length, entropy, and common-password risk.
Very weakEntropy ≈ 0 bits
- •At least 12 characters
- •Mix upper & lower case
- •Contains numbers
- •Contains symbols
- •Not a common password
How to use Password Strength Checker
- 1Type or paste a password.
- 2See the strength meter and entropy score.
- 3Follow the tips to make it stronger.
Frequently asked questions
How is strength calculated?
We estimate entropy from length, character set, and known weak patterns — no external services.
Is the password sent anywhere?
No. The check runs entirely in your browser and is not stored or transmitted.
Does it work offline?
The calculation runs entirely in your browser, so after the first load it works even with a spotty connection.
Is my data private?
Nothing you enter leaves your device. There is no server round-trip and nothing is logged.
Can I use it on mobile?
Yes — the tool is fully responsive on phones, tablets, and desktops.