Check how strong your password is with entropy analysis, estimated crack times, common password detection, and pattern recognition. Get actionable suggestions to improve your password security.
Your password never leaves your browser. All analysis is performed locally.
LevnTools Password Strength Checker lets you secure and verify your data directly in your browser. Everything runs locally in your browser — your sensitive data never leave your device. Unlike cloud-only alternatives that require uploads and accounts, this tool is completely free with no usage limits or watermarks. It is designed for developers generating secure tokens, IT professionals verifying file integrity, security-conscious users protecting passwords — anyone who needs a fast, reliable security tool without the overhead of installing software. Just open the page and start working.
Password Strength Checker is used by a wide range of people. Explore how different groups use this tool:
Generate strong passwords and passphrases with crypto randomness.
Generate crypto-secure random strings in hex, Base64, and more.
Encrypt and decrypt text with AES-256-GCM and a password.
Format, beautify, minify, and validate JSON with syntax highlighting.
Convert text to camelCase, snake_case, kebab-case, and 7 more.
Entropy measures the randomness of a password in bits. Each bit doubles the number of possible combinations an attacker must try. A password with 80 bits of entropy has 2^80 possible combinations.
Online throttled (10/sec) simulates an attacker guessing against a rate-limited website. Offline fast (10B/sec) simulates cracking a stolen password hash with a fast CPU. GPU (100B/sec) simulates using a high-end GPU rig.
Your password is checked against an embedded list of commonly used passwords. The check happens entirely in your browser — the password is never sent anywhere.
The tool detects sequential characters (abc, 123), repeated characters (aaa, 111), and keyboard walk patterns (qwerty, asdf). These patterns drastically reduce the effective entropy of a password.
Yes. Your password never leaves your browser. All analysis runs locally in JavaScript. Nothing is sent to any server, and no data is stored. You can verify this in your browser's network inspector.