Password Generator Online
Generate cryptographically secure passwords using the Web Crypto API. No server involved — passwords never leave your browser.
Quick Answer
A password generator creates cryptographically random passwords using your browser's secure APIs — producing strong, unpredictable credentials that resist brute-force attacks.
What is a Password Generator?
A password generator online creates strong, cryptographically secure passwords instantly. This free password tool uses your browser's crypto.getRandomValues() API to produce truly random credentials that resist brute-force and dictionary attacks — no sign-up required.
26 characters
26 characters
10 characters
32+ characters
Entropy & Password Strength
Password strength is measured in bits of entropy — a mathematical measure of unpredictability. The formula is entropy = log2(pool_size ^ length). More bits means exponentially more combinations an attacker must try.
< 40 bitsEasily cracked with modern hardware in seconds to minutes.
40–60 bitsResistant to casual attacks but vulnerable to dedicated cracking.
60–80 bitsSecure for most applications. Takes years to crack with standard hardware.
> 80 bitsComputationally infeasible to crack — recommended for all credentials.
What is Password Generator Online?
A password generator online is a browser-based tool that creates strong, random passwords using cryptographic APIs. It lets you control length (8–128 characters), toggle character sets, and provides real-time entropy and crack-time metrics for every generated password.
Key Features
Common Use Cases
User Authentication
Generate secure default passwords for new user accounts, admin panels, or temporary access credentials.
API Keys & Tokens
Create high-entropy random strings suitable for API secrets, signing keys, or session tokens.
Testing Security Systems
Validate that password policies, entropy requirements, and strength meters work correctly in your application.
DevOps & Infrastructure
Generate secrets for .env files, Kubernetes secrets, Vault entries, or CI/CD pipeline credentials.
Personal Security
Create strong unique passwords for each service to eliminate credential reuse vulnerabilities.
Security Education
Demonstrate visually how password length and character diversity affect entropy and estimated crack time.
Why Use This Tool
- →Secure by design — Cryptographic randomness ensures passwords cannot be predicted or reproduced.
- →Measurable strength — Entropy bits and crack-time estimates give objective, quantifiable security metrics.
- →Zero backend dependency — Passwords are generated entirely in the browser — never transmitted or stored.
- →Flexible policy compliance — Length and character set options support NIST, PCI-DSS, and custom security policies.
- →Instant results — Generate a new password in milliseconds — regenerate as many times as needed.
Frequently Asked Questions
What is a secure password generator?
A secure password generator creates cryptographically random passwords using APIs like crypto.getRandomValues() — producing credentials that are mathematically unpredictable and resistant to brute-force attacks.
What is password entropy?
Password entropy (measured in bits) quantifies randomness. A 12-character password using all 4 character sets has ~78 bits of entropy — considered very strong for most applications.
Is this password generator safe to use?
Yes. It uses crypto.getRandomValues() for cryptographic randomness and runs entirely in your browser. Nothing is ever sent to a server.
What is a passphrase?
A passphrase is a sequence of random words (e.g., correct-horse-battery-staple) that is easier to remember but provides strong entropy through length.
Is this password generator free?
Yes. The Password Generator on NexoraTools is completely free and requires no account or installation.