Password & Passphrase Generator

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Generate secure passwords with real-time entropy analysis, GPU & quantum crack time estimates, HIBP breach database check, and policy compliance testing. Five generation modes including EFF Diceware passphrases. 100% client-side — your passwords never leave your browser.

Click "Generate" to create a password
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🎰 RNG Engines 5
Each character is generated by a randomly-selected engine. Using multiple RNG algorithms with different entropy sources makes the password resistant to weaknesses in any single generator.
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How Does the Max Intel Password Generator Work?

Max Intel's Password Generator creates cryptographically secure passwords using four independent random number generators — Web Crypto API, Math.random (Xorshift128+), a Mersenne Twister implementation, and a Linear Congruential Generator. It checks passwords against Have I Been Pwned's database of 900+ million breached passwords and analyzes strength with zxcvbn.

CSPRNG (Cryptographically Secure PRNG)
A pseudorandom number generator that produces output computationally indistinguishable from true randomness — required by NIST SP 800-90A for security applications including password generation.
Shannon Entropy
A mathematical measure of randomness in bits. A password with N equally likely characters from an alphabet of size A has entropy of N × log₂(A) bits. NIST recommends minimum 80-bit entropy for high-security passwords.
zxcvbn
A realistic password strength estimator (developed by Dropbox) that models actual attacker strategies — dictionary words, keyboard patterns, l33t substitutions, and date formats — rather than relying on simplistic character-class rules.
HIBP (Have I Been Pwned)
A breach notification service by Troy Hunt containing 900+ million compromised passwords. The k-anonymity API allows checking password breach status without exposing the full password hash.

Five Generation Modes

The generator supports five distinct modes to match different use cases. Random character mode creates traditional passwords from configurable character pools. Passphrase mode uses the EFF's curated 7,776-word Diceware list — each word adds 12.9 bits of entropy, and a 5-word passphrase provides approximately 64.5 bits — meeting the minimum threshold recommended by NIST SP 800-63B (Digital Identity Guidelines) for memorized secrets. PIN mode generates numeric codes with options to prevent sequential digits and duplicates. Pronounceable mode creates phonetically plausible passwords using consonant-vowel patterns that are easier to type and remember than pure random strings. Pattern mode lets you define exact character class sequences — useful for systems with rigid password composition requirements. Notably, NIST SP 800-63B Section 5.1.1 now advises against mandatory complexity rules (e.g., requiring symbols), finding that they reduce usability without meaningfully improving security.

Multi-Engine RNG for Algorithmic Diversity

Unlike typical password generators that rely on a single source of randomness, Max Intel's generator offers five toggleable RNG engines: the Web Crypto API (operating system entropy pool), Chance.js (a high-level random data generator), seedrandom (ARC4 cipher-based PRNG), the browser's native Math.random() (V8 xorshift128+), and a timestamp entropy mixer that combines performance.now() microsecond jitter with cryptographic randomness. Each character in your password is generated by a randomly-selected engine (chosen via Web Crypto). This algorithmic diversity means that even if one engine has a subtle bias or predictability, the others compensate — the password inherits strength from all engines simultaneously.

RNG EngineAlgorithmCSPRNGSpeedUse Case
Web Crypto APIOS entropy poolYesFastPrimary security-grade generation
Math.randomXorshift128+NoFastestCross-engine entropy mixing
Mersenne TwisterMT19937NoMediumStatistical quality verification
LCGLinear CongruentialNoFastAdditional entropy source

zxcvbn Pattern Analysis

Based on Dropbox's open-source password strength estimator, cited by OWASP Password Storage Cheat Sheet as a recommended approach for realistic strength assessment.

Beyond simple entropy calculation, Max Intel uses Dropbox's zxcvbn library — the same algorithm used by major password managers like 1Password and Bitwarden. Unlike naive strength checkers that only count character types, zxcvbn detects real-world attack patterns: dictionary words (including common substitutions like p@ssw0rd), keyboard spatial patterns (qwerty, zxcvbn), repeated characters, sequential patterns, dates, and names. It then estimates realistic crack times based on how actual password cracking tools work. This gives you actionable feedback about why a password is weak, not just that it is.

Real-Time Entropy Analysis

Every generated password is instantly analyzed for entropy (measured in bits), character composition, and estimated crack times across three scenarios: an online attack throttled to 1,000 guesses per second, an offline GPU attack at 100 billion guesses per second (reflecting modern hashcat performance against unsalted MD5 hashes), and a theoretical quantum attack using Grover's algorithm which effectively halves the security bits. The visual entropy meter and composition breakdown help you understand exactly why a password is strong or weak.

HIBP Breach Database Check

As of 2025, Have I Been Pwned tracks over 14 billion compromised accounts across 800+ data breaches, making it the most comprehensive credential breach database available.

The breach check feature uses the Have I Been Pwned Passwords API with k-anonymity protection. Your password is SHA-1 hashed locally in your browser, and only the first 5 characters of the hash prefix are sent to the HIBP API. The API returns all matching hash suffixes from its database of over 900 million breached passwords, and your browser checks locally whether your password's full hash appears in the results. This means your password — or even its complete hash — never leaves your device.

Policy Compliance Testing

Tests against NIST SP 800-63B, PCI DSS v4.0 Requirement 8, and common enterprise policies. NIST's 2024 guidance emphasizes password length over complexity, recommending a minimum of 8 characters with no upper limit and mandatory breach database screening.

Generated passwords are automatically tested against three common security policy frameworks. NIST SP 800-63B emphasizes password length and breach database checks over complexity requirements. PCI DSS requires a minimum of 7 characters with a mix of numeric and alphabetic characters. Standard corporate policies typically require 12+ characters with uppercase, lowercase, digits, and symbols. The compliance checker tells you whether your password would pass each policy.

Password Generator — Frequently Asked Questions

How does entropy measure password strength?

Entropy measures password randomness in bits. Each bit doubles the number of possible combinations an attacker must try. A password with 40 bits of entropy has about 1 trillion possible combinations. NIST recommends a minimum of 64 bits for moderate security. For high-value targets like encryption keys, 80+ bits is recommended. Max Intel calculates entropy based on the actual generation method — character pool size and password length for random passwords, or word list size and word count for passphrases.

What is a Diceware passphrase and why is it more secure?

A Diceware passphrase is a password made of randomly selected words from a curated word list (like the EFF's 7,776-word list). Each word adds approximately 12.9 bits of entropy. A 6-word passphrase has about 77.5 bits of entropy — equivalent to a 12-character random password but far easier to remember. The XKCD comic "correct horse battery staple" popularized this concept. Max Intel uses the EFF word list and cryptographically secure random number generation.

How does the HIBP breach check work without sending my password?

Max Intel uses the Have I Been Pwned k-anonymity API. Your password is SHA-1 hashed locally in your browser, and only the first 5 characters of the hash are sent to the API. The API returns all known breached hashes that start with those 5 characters, and your browser checks locally if your full hash is in the list. This means your actual password — or even its full hash — never leaves your device.

What is quantum-resistant password strength?

Quantum computers running Grover's algorithm could theoretically crack passwords at the square root of the classical time — effectively halving the bits of security. A password with 80 bits of classical entropy would have 40 bits against a quantum attack. For quantum resistance, aim for 128+ bits of entropy. Max Intel shows estimated crack times for both classical GPU attacks and theoretical quantum scenarios.

What password policies does the compliance checker test?

Max Intel tests against NIST SP 800-63B (minimum 8 characters, no composition rules, blocklist check), PCI DSS (minimum 7 characters, mix of numeric and alphabetic), and common corporate policies (12+ characters, uppercase, lowercase, numbers, symbols required). NIST's modern guidelines notably recommend against forced character composition and periodic password changes, instead emphasizing length and breach database checks.

Is it safe to generate passwords in a web browser?

Max Intel's generator runs entirely in your browser using the Web Crypto API (window.crypto.getRandomValues), which is a cryptographically secure random number generator built into all modern browsers. No passwords are ever transmitted to any server, stored, or logged. For maximum security, you can use the page offline — once loaded, disconnect from the internet and generate passwords. The source code is fully visible in the page source.

What is multi-engine RNG and why does it improve security?

Most password generators use a single random number generator. Max Intel uses five different engines simultaneously — Web Crypto API, Chance.js, seedrandom, Math.random(), and timestamp entropy mixing. Each character is generated by a randomly-selected engine. This algorithmic diversity means that even if one engine has a subtle bias, the others compensate. The engine selection itself is done via the cryptographically secure Web Crypto API. You can toggle engines on/off and see exactly how many characters each engine contributed.

What is zxcvbn and how does it analyze passwords?

zxcvbn is a password strength estimator developed by Dropbox that goes far beyond simple character-counting. It detects real attack patterns: dictionary words (including l33t substitutions like p@ssw0rd), keyboard spatial patterns (qwerty, zxcvbn), repeated characters, sequences (abcd, 1234), and dates. It then calculates realistic crack time estimates based on how actual password cracking tools like hashcat work. The result is actionable feedback — not just "weak" or "strong" but why and what to improve.