Password Strength Checker
Check the strength of your password with real-time feedback and actionable improvement tips.
About Password Strength Checking
Password strength checkers evaluate how resistant a password is to being guessed or cracked. This tool analyses your password across multiple dimensions — length, character diversity, common patterns, and estimated cracking time — and gives actionable feedback on how to improve it.
What makes a password strong?
Modern guidance from NIST (SP 800-63B) and security researchers has shifted away from complexity requirements (forcing uppercase, numbers, symbols) towards focusing on:
- Length — The single most important factor. A 20-character password with only lowercase letters is stronger than an 8-character password with symbols.
- Unpredictability — Avoid dictionary words, names, dates, and predictable substitutions like
@foraor3fore. Attackers' wordlists include these patterns. - Uniqueness — Every account should have a different password. Password reuse is the leading cause of account takeovers after data breaches.
Common weak password patterns
- Names + birth year:
james1990 - Keyboard walks:
qwerty,123456,zxcvbn - Word + number:
password123 - Leet-speak substitutions:
p@ssw0rd - Common phrases:
iloveyou,letmein
Attackers' cracking tools include all of these patterns as their first guesses.
How to use this tool
This tool performs analysis entirely in your browser — your password is never sent to any server. It evaluates entropy, checks for common patterns, and shows an estimated crack time. Use it to understand your existing passwords, then use the Password Generator to create stronger ones.