Password Strength Checker
Check a password right before signing up or changing it. The tool inspects length, character variety, and common patterns, then shows an estimated crack time and concrete improvements. Nothing is sent over the network.
How to Use
Type or paste the password into the input field. Toggle the eye icon to show or hide it.
A 0–100 score, label (Weak / Fair / Good / Very Strong), and estimated crack time (instant → many billions of years) appear instantly.
A checklist (length, upper/lower/digits/symbols) and warnings (common passwords, sequences) show what's weak so you can fix it.
FAQ
Does my password get sent to a server?
No. Checking happens entirely in browser JavaScript — open the Network tab to verify. Nothing leaves the page.
Is "Very Strong" a guarantee of safety?
This tool checks length, character variety, and simple patterns only. For thoroughness (e.g. matching against breached-password hashes), use a dedicated service. For everyday signups it's enough.
How is crack time calculated?
Entropy (bits) = log2(charset size) × length, brute-forced at 1e10 guesses/sec (modern consumer GPU). Real-world hashing (bcrypt / scrypt / Argon2) makes it dramatically slower.
Are non-Latin characters safer?
Korean, Chinese, and Japanese characters expand the charset enormously, so a same-length password using them has more entropy. But many sites reject non-Latin passwords, so compatibility is risky.
Where is the data stored?
Nowhere. Closing the tab clears the input; nothing is written to localStorage or cookies.
