Password Security Analyzer & Generator

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Password Options

Disclaimer

All analysis (strength, patterns, entropy) occurs entirely in the browser. The password never leaves your device for analysis. It does not log, store, or track any passwords entered into the tool.

This tool does not assess whether the submitted password contains personal information.

For breach verification, use the option below.

This tool checks your password against the Have I Been Pwned? password database using the k-Anonymity model. Only the first 5 characters of your password's SHA-1 hash are sent to the API. Powered by Have I Been Pwned? API.

Strength: -

Est. Crack Time: -

Other Metrics

Offline Attack:

Slow Hash: -

Fast Hash: -

Online Attack:

Throttled: -

No Throttle: -

Entropy Scale (bits)

<30
30-59
60-89
90-119
120+

Minimum Requirements

  • Lowercase (a-z)
  • Uppercase (A-Z)
  • Number (0-9)
  • Symbol (!@#...)
  • At least 16 characters
  • Avoids repeated chars

Core Strength Metrics: Anatomy of a Strong Password

A sophisticated password analyzer dissects passwords based on multiple criteria. These foundational metrics provide an accurate assessment of a password's resilience against common attack methodologies.

Password Cracking Time

Relative time to crack passwords by length and complexity.

Based on an assumption of 1 trillion guesses/second.

Simple (a-z) Complex (A-Z, a-z, 0-9, #?!)

Illustrative: Estimated crack times dramatically increase with length.

Conceptual Character Type Strength

A mix of uppercase, lowercase, numbers, and symbols increases complexity. However, forced, predictable complexity is less secure than genuine randomness or greater length.

Entropy: The Scientific Measure of Randomness

Entropy, measured in bits, quantifies unpredictability. Higher entropy means exponentially more guesses are needed to crack a password.

Aim for 80+ Bits

This level is typically considered strong for important accounts. The formula E = L * log2(R) (Length × log base 2 of Character Pool Size) is fundamental.

Detecting Common Weaknesses

Analyzers must identify and penalize common pitfalls that attackers exploit:

  • ✗ Dictionary words (e.g., "password", "admin")
  • ✗ Sequential characters (e.g., "abc", "123")
  • ✗ Repeated characters (e.g., "aaa", "111")
  • ✗ Keyboard patterns (e.g., "qwerty")
  • ✗ Predictable substitutions (e.g., P@$$wOrd)

Algorithms like zxcvbn provide holistic, pattern-based strength estimation beyond simple checks.

zxcvbn Score Interpretation

The zxcvbn model returns a raw score from 0 to 4, representing a qualitative measure of the password's strength. Hover over each score for its meaning:

0
1
2
3
4

A higher score indicates a more secure password that is harder to guess or crack.

Crack Time Estimations

zxcvbn provides crack time estimations based on different potential attack scenarios. Click on each scenario to reveal details:

Simulates an attacker with password hashes, cracking offline with high computing power. Slowed by strong, computationally expensive hashing algorithms (like bcrypt, scrypt, PBKDF2) with unique salts. Rate: ~10,000 guesses/second. A zxcvbn score of 3 or 4 offers good protection.

Similar to slow hash, but assumes hashes created using fast algorithms (like MD5 or SHA-1) allowing many more guesses per unit of time. Rate: ~10 billion guesses/second.

Models an online attack where the service actively limits login attempts (e.g., account lockouts, CAPTCHAs). This drastically slows down the attacker. Rate: ~100 guesses/hour. A score of 1 or higher provides some protection here.

Represents an online attack where the service fails to limit login attempts effectively, allowing rapid guesses. Rate: ~10 guesses/second. A score of 2 or higher is needed for better protection.

These estimates highlight how password strength relates to various real-world attack vectors and the importance of server-side security measures like strong hashing and rate limiting.

Password vs. Passphrase

Passwords

Shorter strings of characters (letters, numbers, symbols). Can be harder to remember and more susceptible to cracking due to brute-force or dictionary attacks targeting shorter strings.

Passphrases

Longer, consisting of several random words or phrases. Often easier to remember and significantly more secure than traditional passwords due to their length and higher entropy.

Proactive Defense: Checking Against Known Breaches

A theoretically strong password is useless if already compromised. Modern analyzers MUST check passwords against databases of breached credentials, like HIBP Pwned Passwords.

The k-Anonymity Process Flow

This privacy-preserving technique ensures the actual password is never sent to an external server:

1️⃣ User inputs password (client-side).
2️⃣ Password hashed locally (e.g., SHA-1).
3️⃣ Small hash prefix sent to breach database.
4️⃣ Server returns list of full hashes matching prefix.
5️⃣ Client compares full local hash against returned list.
🛡️

Why It's Essential

Many passwords, even complex ones, have appeared in data breaches. This check protects against credential stuffing attacks, a major threat.

NIST[1] & OWASP[2] Recommend It!

  1. [1]: National Institute of Standards and Technology. https://nist.gov/
  2. [2]: Open Worldwide Application Security Project. https://owasp.org/

Effective Guidance: User Interface (UI) & Experience (UX)

The analyzer's effectiveness hinges on how it communicates findings. Intuitive UI/UX is key to driving better password practices.

Key UI/UX Features

  • ✔️ Real-Time Feedback: Instant strength evaluation as the user types.
  • ✔️ Clear Visual Cues: Color-coded bars (🔴🟠🟡🟢🔵) and textual labels (Very Weak, Weak, Fair, Good, Strong).
  • ✔️ Actionable Recommendations: Specific advice on *why* it's weak and *how* to improve.
  • ✔️ Estimated Time to Crack: Tangible risk illustration (e.g., "seconds", "centuries").

Building Trust: Foundational Security & Privacy by Design

Handling sensitive password data demands unwavering commitment to security and privacy. These principles are non-negotiable for user trust.

💻

Client-Side Processing

All analysis (strength, patterns, entropy) occurs *entirely in the user's browser*. The password never leaves their device for analysis.

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No-Logging Policy

The service must explicitly state it does *not* log, store, or track any passwords entered into the tool.

🔒

HTTPS Everywhere

The analyzer's website *must* use HTTPS to encrypt all communications, protecting the tool's code and user interaction.

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Security Transparency

Clear, prominent communication of these security and privacy practices is vital for alleviating user concerns and building trust.

The Educational Mandate: Empowering Users

A password analyzer should be an educational resource, fostering lasting improvements in security behavior by explaining the "why" behind recommendations.

🔑 Uniqueness is Key

Use different, strong passwords for every online account to limit breach impact.

📏 Length Over Complexity

Greater length generally offers more security than forced, patterned complexity.

👤 Avoid Personal Information

Don't use birthdays, names, or other easily guessable details.

🗄️ Use Password Managers

They generate, store, and manage strong, unique passwords securely.

🛡️ Enable Multi-Factor Authentication (MFA)

MFA adds a critical extra layer of security beyond just the password.

💡 Explain the "Why"

Contextual explanations for why a password is weak improve user understanding and adoption of best practices.