Password Generator
Generate secure, random passwords instantly. 100% free. Runs in your browser.
More Password & Security Tools
Random Password
Generate cryptographically random passwords with full control over length and character types.
Strong Password
Pre-set to maximum security defaults. 20+ characters, all character types, entropy display.
Strength Checker
Test any password's strength with real-time entropy analysis and crack time estimates.
Crack Time Calculator
See how long your password would resist a single GPU, cluster, botnet, or quantum computer.
Passphrase Generator
Generate memorable multi-word passphrases using Diceware and EFF wordlists.
Memorable Password
Easy-to-remember passwords using word-number-symbol patterns.
PIN Generator
Secure random PINs that avoid common patterns like 1234 or 0000.
Leak Checker
Check if your password appears in known data breaches using Have I Been Pwned.
Username Generator
Cool, unique usernames for gaming, professional, or aesthetic profiles.
SSH Key Generator
Create Ed25519, RSA, and ECDSA key pairs entirely in your browser.
UUID Generator
Generate v4, v7, and nil UUIDs. Bulk generation up to 1000.
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Encode and decode Base64 text and files instantly.
How to Create a Strong Password
- Use at least 16 characters. Length is the single biggest factor in password strength. Every additional character exponentially increases the time to crack. See the math.
- Mix all character types. Uppercase, lowercase, numbers, and symbols give you a pool of 95 characters — maximizing entropy per character.
- Never use personal information. Names, birthdays, pet names, and addresses are the first things attackers try. They're found in social media scraping databases.
- Avoid dictionary words and patterns. Even with clever substitutions (@ for a, 3 for e), cracking tools have rules for every common variation. Use our Strength Checker to verify.
- Use a unique password for every account. Password reuse is the #1 cause of account compromise. A password manager makes this effortless. Check existing passwords with our Leak Checker.
How Our Generator Works
Our password generator uses the Web Crypto API (crypto.getRandomValues()) — the same cryptographically secure random number generator that powers TLS encryption, SSH key generation, and blockchain wallets.
Unlike Math.random(), which uses predictable algorithms (xorshift128+), the Web Crypto API draws entropy from hardware sources in your operating system: CPU timing jitter, interrupt timing, and thermal noise. This makes the output computationally indistinguishable from true randomness.
Every password is generated locally in your browser. No data is sent to any server — ever. You can verify by checking your browser's Network tab or simply disconnecting from the internet before generating.
About Our Security Standards
PassGen is built on three principles:
- Client-side only. All 23 tools run in your browser. The only exception is the Leak Checker, which uses the Have I Been Pwned k-anonymity API (only 5 characters of a hash prefix are sent — your full password is never transmitted).
- No tracking. No cookies, no analytics pixels, no fingerprinting. The only
localStorageitem is your light/dark theme preference. - Transparency. Our strength scoring, entropy calculations, and crack time estimates are based on published cryptographic research and real-world GPU benchmarks.
Password Security FAQ
Is it safe to use an online password generator?
Yes — our generator runs 100% in your browser using the Web Crypto API. Your passwords are never sent to any server. You can verify by disconnecting from the internet — the tool still works.
How long should my password be?
At least 16 characters for most accounts. For high-security accounts (email, banking, password manager), use 20+. Each additional character exponentially increases crack time.
What is a passphrase and should I use one?
A passphrase is a password made of multiple random words (e.g., "correct-horse-battery-staple"). Passphrases are easier to remember and can be very strong if they're long enough (4+ words). Try our Passphrase Generator.
How often should I change my password?
NIST no longer recommends periodic password changes. Change your password only if: it's been exposed in a breach, you suspect unauthorized access, or it's weak. Frequent forced changes lead to weaker passwords.
Should I use a password manager?
Absolutely. A password manager lets you use unique, strong passwords for every account without memorizing them. Bitwarden (free), 1Password, and KeePass are excellent options.
What makes our generator different from Chrome's built-in one?
Browser generators are tied to their password manager and offer limited customization. Our tool gives you full control over length, character types, and bulk generation — and you can use the passwords with any password manager.
Can quantum computers crack my password?
Grover's algorithm halves entropy against quantum attacks (128-bit → 64-bit effective). For now, quantum computers capable of this don't exist. A 20+ character password with all character types provides ~131 bits of entropy — safe even against theoretical quantum attacks. Check with our Crack Time Calculator.
What does "entropy" mean for passwords?
Entropy measures password randomness in bits. Each bit doubles the number of combinations an attacker must try. 80+ bits is strong; 128+ is effectively uncrackable. See details with our Entropy Calculator.