Password Strength Checker
Free password strength checker. Analyze any password locally: entropy in bits, strength score, missing character classes and estimated time to crack.
How to use Password Strength Checker
- 1
Type or paste a password into the analyzer.
- 2
Watch the live score, entropy and crack-time estimate update.
- 3
Review the checklist to see exactly which properties are missing.
- 4
Strengthen it (or generate a new one) until the score passes 80.
Key features
Entropy measured in bits
Estimated time to crack
0–100 strength score with color gauge
Detects common passwords & sequences
Missing character-class warnings
100% local analysis — nothing is transmitted
Pro tip
Test a few of your passwords here (locally, safely). If any score under 50, replace it with a generated one — the pattern is: length + randomness beats cleverness every time.
Password Strength Checker — FAQ
Yes — the analysis runs entirely in your browser. Your password is never sent anywhere, which is exactly why a local checker is safer than a web-based one.
Aim for 80+. That usually means 16+ characters mixing upper and lower case, numbers and symbols — with no dictionary words or sequences.
The tool estimates total guesses as 2^entropy and divides by a modern offline attack rate of ~10 billion guesses per second.
Entropy measures uncertainty in bits: a 128-bit password has 2^128 possible values, making it effectively uncrackable by brute force.
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