Password Strength Checker
Analyze password strength with detailed feedback and suggestions
Password Strength Checker
Score Breakdown
Statistics
Character Composition
Usage Examples
Weak Password
See how a common weak password like "password123" scores and what improvements are suggested.
Medium Password
Analyze a moderately strong password with mixed characters to see how it can be improved.
Strong Password
Check a strong passphrase-style password to see maximum security characteristics.
Features
Real-Time Analysis
Password strength is analyzed instantly as you type with visual strength meter
Entropy Calculation
Shannon entropy calculation in bits to measure password randomness and unpredictability
Crack Time Estimation
Estimated time to crack based on 10 billion guesses per second (modern GPU)
100% Client-Side
Your password never leaves your browser. All processing happens locally in JavaScript
How to Use?
Enter Password
Type or paste your password into the input field. Analysis begins immediately.
Review Analysis
Check the strength meter, score breakdown, entropy, and crack time estimation.
Follow Suggestions
Apply the improvement suggestions to create a stronger, more secure password.
Frequently Asked Questions
What Does This Tool Actually Measure?
This password strength checker evaluates your password across multiple dimensions: length, character diversity (uppercase, lowercase, numbers, symbols), common pattern detection (keyboard walks like "qwerty", repeated characters, dictionary words), and mathematical entropy. It combines all of these into a practical strength score and estimates how long it would take to crack using modern GPU hardware at 10 billion guesses per second.
Why Most Passwords Are Weaker Than You Think
People are terrible at randomness. We capitalize the first letter, put numbers at the end, and swap "a" for "@" thinking we're clever. Attackers know all these patterns and their tools try them first. A password like "P@ssw0rd123!" looks complex but falls in seconds because it's a known pattern. True strength comes from length and genuine randomness - which is why a passphrase like "correct-horse-battery-staple" can be stronger than "Tr0ub4dor&3".
Understanding Entropy
Entropy measures password randomness in bits. Each bit doubles the number of possible combinations. A password with 40 bits of entropy has about 1 trillion possibilities - sounds like a lot until you realize modern GPUs can test that many in about 100 seconds. At 60 bits, you're looking at years. At 80+ bits, centuries. This tool calculates entropy based on the actual character pool you're using, so you can see exactly where you stand.
Practical Tips That Actually Work
Use a password manager and let it generate random passwords - that's the real answer. If you must memorize a password, use a passphrase of 4-5 random words. Enable two-factor authentication everywhere you can. Never reuse passwords across sites. And check your passwords against breach databases (haveibeenpwned.com) periodically.
Complete Privacy
Your password never leaves your browser. There's no server call, no analytics event, no logging of any kind. The analysis runs entirely in JavaScript on your device. You can disconnect from the internet and the tool works identically.