Random Password Generator
Generate cryptographically secure random passwords instantly. Powered by Web Crypto API.
What Makes a Password Truly Random?
Randomness in passwords is not about looking random to the human eye — it's about being unpredictable to an attacker. A password like Tr0ub4dor&3 might look complex, but it follows predictable substitution patterns that cracking software exploits in seconds.
True randomness comes from a Cryptographically Secure Pseudorandom Number Generator (CSPRNG). Our tool uses the browser's crypto.getRandomValues() API, which draws entropy from your operating system's hardware-level randomness sources — the same mechanism used for TLS encryption and cryptographic key generation.
CSPRNG vs. Math.random()
Math.random() uses algorithms like xorshift128+ that are designed for speed, not security. Their output is deterministic: given the internal state, every future value can be predicted. This makes them unsuitable for password generation.
A CSPRNG like crypto.getRandomValues() uses hardware entropy (CPU timing jitter, interrupt timing, thermal noise) to seed its output, making prediction computationally infeasible — even for an attacker who knows the algorithm.
Why Browser-Generated Passwords Are Safer
Many password generators run on servers: you click "generate," the server creates a password, and sends it back to you. This creates two risks:
- Man-in-the-middle — The password travels across the network, where it could be intercepted.
- Server logs — The password may be logged, cached, or stored temporarily on the server.
Our generator runs 100% in your browser. The password is created on your device and never transmitted. You can verify this by opening your browser's DevTools → Network tab and confirming zero requests are made when you generate a password.
How Many Characters Do You Need?
| Length | Character Types | Entropy (bits) | Crack Time (10B guesses/sec) |
|---|---|---|---|
| 8 | All | ~53 | ~28 hours |
| 12 | All | ~79 | ~1.9 million years |
| 16 | All | ~105 | ~12.8 billion billion years |
| 20 | All | ~131 | Heat death of universe |
For most accounts, 16 characters with all character types is the sweet spot between security and usability. For your email and password manager master password, consider 20+.
Frequently Asked Questions
Is it safe to use an online password generator?
Yes — as long as the generator runs entirely in your browser. Our tool uses the Web Crypto API (CSPRNG) to generate passwords locally on your device. No password is ever sent to a server. You can verify this by disconnecting from the internet and confirming the tool still works.
What makes a password truly random?
True randomness requires a cryptographically secure pseudorandom number generator (CSPRNG). We use crypto.getRandomValues(), which draws entropy from your operating system's hardware random number generator. This is fundamentally different from Math.random(), which is predictable and unsuitable for security.
How long should a random password be?
For most accounts, 16 characters is a strong baseline. For high-security accounts (banking, email, password manager master password), use 20+ characters. Every additional character exponentially increases the time required to crack the password.
Should I include symbols in my password?
Yes. Including symbols alongside uppercase, lowercase, and numbers increases the character pool from 62 to 95, which dramatically increases entropy. A 16-character password with all character types has roughly 105 bits of entropy — effectively uncrackable by brute force.
Are browser-generated passwords safer than server-generated ones?
Yes. When a server generates your password, it exists briefly on that server — creating a potential attack surface. Browser-generated passwords never leave your device, eliminating the man-in-the-middle risk entirely. This is why we run everything client-side.
Can I generate multiple passwords at once?
Yes. Use the "Generate Bulk" button to create up to 50 random passwords at once. Each is independently generated with the same CSPRNG, so every password is equally secure.
How is this different from the passwords Chrome or Safari suggest?
Browser-generated passwords are also secure, but they're tied to that browser's password manager. Our tool gives you full control over length, character types, and quantity — and you can use the generated passwords anywhere, with any password manager.