Test Your Password Strength Check how strong your password is with detailed scoring, crack time estimates, and improvement suggestions.

Under the hood, the Password Strength Checker relies on the zxcvbn library developed by Dropbox, which employs a combination of pattern matchers to analyze the password's complexity. These pattern matchers include dictionary, spatial (keyboard), repeat, sequence, date, and l33t substitution, allowing it to detect common patterns like dictionary words, keyboard sequences, dates, and leetspeak substitutions. The tool uses React's useState hook to store the input password and showPassword state, while the useMemo hook is used to memoize the result of the zxcvbn function, which returns an object containing the password's score, crack time estimates, and feedback.

The score, ranging from 0 to 4, is mapped to crack time thresholds based on the minimum number of guesses required to crack the password. For instance, a score of 0 indicates a very weak password that can be cracked in less than 10 seconds, while a score of 4 represents a very strong password that would take over 10 years to crack. The tool also generates detailed feedback, including warnings and suggestions for improvement, which are displayed in the UI as a sequence analysis of the password's patterns. This feedback is based on the zxcvbn library's analysis of the password's structure and composition.

In terms of browser APIs, the tool uses JavaScript's built-in functions to handle user input and update the UI accordingly. The zxcvbn library itself does not rely on any external APIs or file formats, making it a self-contained solution for password strength analysis. By using this library in conjunction with React, the Password Strength Checker provides a seamless and intuitive experience for users to evaluate and improve their password security. The tool's use of technical terms like crack time estimates, leetspeak substitutions, and spatial pattern matching demonstrates its focus on providing accurate and informative feedback to users.