tejasreejilla/password-analyzer

This project is a password strength checker that runs entirely in your web browser. Instead of filling out a form and clicking a button, you get feedback the moment you start typing a password: a score from 0 to 100, a color coded status from very weak to very strong, and a visual progress bar that updates in real time. Under the hood, the tool looks at several things at once. It checks the password's length and tells you whether it is long enough. It looks at complexity, meaning whether you have mixed in lowercase letters, uppercase letters, numbers, and special characters, and it shows which of those are missing. It also calculates entropy, a measure of how random and unpredictable the password is, using a method called Shannon entropy plus a theoretical maximum based on how many possible characters could have been used. On top of that, it checks the password against a list of over 100 common passwords and looks for simple patterns, like keyboard sequences or predictable variations of a common word, and warns you if it finds one. Finally, it estimates how long a brute force attack would take to crack the password, assuming an attacker could try one billion guesses per second. Everything runs locally in the browser. No password is ever sent to a server, no network requests are made, and nothing is saved or logged, so it works fine even completely offline. To use it, you can simply double click the index.html file to open it in your browser, or start a small local Python web server and visit it at localhost, or use the Live Server extension in VS Code. The project is built with HTML, CSS, and JavaScript for the interface, with some optional Python modules included for the same kind of analysis outside the browser. This is a small side project built for a computer science assignment, and it currently has 16 stars on GitHub.