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Password Strength Analyzer

Analyze password strength in real-time. Displays detailed information such as crack time, entropy, character set size, and score. All processing is performed locally in the browser, and passwords are not sent to the server.

How to use

About this tool

Analyzes password strength in real-time. Displays detailed information such as crack time, entropy, character set size, and score. All processing is performed locally in the browser, and passwords are not sent to the server.

How to use

Enter a password in the input field; analysis results update in real-time. Crack duration, password length, entropy, character set size, and score (weak/medium/strong) are displayed instantly.

Options

Input: Password string (max 1000 characters). When you enter a password, the following information is displayed in real-time: crack duration (time needed for brute-force attack), password length, entropy (in bits), character set size (number of character types used), score (0-100) and category (weak/medium/strong).

Use cases

• Checking password strength • Verifying compliance with security policies • Validating generated passwords • Evaluating existing passwords • Security education and training

How it works

Entropy is calculated using Shannon entropy (information-theoretic entropy). Crack time is calculated based on character set size and password length, assuming a standard attack speed (1 trillion attempts/second). Score is a composite of length (40 points), entropy (40 points), and character set size (20 points).

Privacy and data

All calculations are performed in the browser; passwords are never sent to a server. Passwords are handled in memory and reset when the page is reloaded.

FAQ

Q: What phonetic alphabets are supported?
A: The NATO Phonetic Alphabet (Alpha, Bravo, Charlie…) for English and a Japanese phonetic scheme are both available. Select the scheme that matches your use case.
Q: What is the NATO Phonetic Alphabet used for?
A: The NATO Phonetic Alphabet (officially the ICAO spelling alphabet) is the international standard for spelling out letters clearly over radio, telephone, and air traffic communications. Each letter has a unique word that sounds distinct even in poor audio conditions.
Q: Can I convert numbers as well as letters?
A: Yes. Digits 0–9 are also converted using the phonetic scheme's number words (e.g. 1 → "One" / "Unaone" in NATO). Enter any alphanumeric string.
Q: Is this useful for reading out confirmation codes or serial numbers?
A: Exactly. Phonetic codes are ideal for reading order numbers, license plates, serial numbers, or any string character-by-character to eliminate ambiguity between similar-sounding letters like B/P or M/N.
Q: Does this tool send my text to a server?
A: No. All conversion is performed entirely in the browser. Your text is never sent to any server.