Free Password Generator & Strength Tester
Generate cryptographically secure random passwords and test the strength of existing ones. Configure length (8–64 chars), character types, and bulk generation (1, 5, or 10 at once). 100% client-side — your passwords never leave your browser.
Password Strength Tester
🔒Your passwords are generated and tested entirely in your browser using the Web Crypto API (crypto.getRandomValues). Nothing is sent to any server. We never see, store, or transmit your passwords.
Password Security: What You Need to Know in 2025
Credential stuffing, phishing, and brute-force attacks are responsible for the vast majority of account compromises. The fundamental defense is simple: use a unique, randomly-generated password for every account. Yet over 60% of users still reuse passwords across multiple sites. Understanding why password strength matters — and what actually makes a password strong — is the first step to better security hygiene.
How Password Cracking Works
Modern GPU-based cracking rigs can attempt 100+ billion MD5 hashes per second. Dictionary attacks try common words, names, and known breached passwords first. Hybrid attacks combine dictionary words with numbers and symbols (Password123! is immediately cracked). Rule-based attacks systematically apply common substitutions (@ for a, 3 for e, ! at the end). The only defense is true randomness and sufficient length — human-chosen “complex” passwords are predictably patterned.
Time-to-Crack by Password Type
| Example | Type | Time to crack (100B/sec) |
|---|---|---|
| password | Common word | Instantly |
| Password123! | Common pattern | Under 1 second |
| Tr0ub4dor&3 | XKCD-style | Under 1 hour |
| k9#mL2pQ | 8-char random | Minutes to hours |
| xK9#mL2pQr7$ | 12-char random | Decades |
| wX#4kR9mPz$2Hn7@ | 16-char random | Centuries |
Frequently Asked Questions
Is this password generator safe to use?
Yes. This generator runs entirely in your browser using the Web Crypto API (crypto.getRandomValues), which provides cryptographically secure random numbers. Your passwords are never transmitted to any server, never logged, and never stored. You can verify this by opening browser DevTools (F12), going to the Network tab, and confirming no network requests are made when you generate a password. The source code is also open — there's nothing hidden.
How long should my password be?
For most accounts, a minimum of 12 characters is the current security baseline. For sensitive accounts (banking, email, cloud storage), use 16+ characters. For master passwords and encryption keys, 20+ characters. Length is the most important factor: a random 12-character password using only lowercase letters has more entropy than a 8-character password using all character types. Password managers remove the need to remember long passwords, so use 20+ characters everywhere.
What is entropy and why does it matter for passwords?
Entropy measures password randomness in bits. Higher entropy means more guessing is required to crack the password. Entropy = log2(charset size) × length. A 12-character password using all 94 printable ASCII characters has 12 × log2(94) ≈ 78 bits of entropy. At 100 billion guesses per second (modern GPU cracking speed), this takes centuries to crack. Below 50 bits (e.g., 8 characters, mixed case) can be cracked within hours by dedicated hardware.
Should I use a password manager?
Yes, unconditionally. Password managers (Bitwarden, 1Password, KeePassXC) let you use a unique, random, 20+ character password for every site without needing to remember any of them. The most common cause of account compromise is password reuse — using the same password across multiple sites means one breach exposes all your accounts. Free options: Bitwarden (fully-featured, open source) and the built-in password managers in Chrome/Safari/Firefox are all reasonable choices.
What characters should I include or exclude?
For maximum security, include all character types: uppercase, lowercase, numbers, and symbols. For compatibility with systems that restrict special characters (some banking or government sites), uppercase + lowercase + numbers is a safe fallback. The 'exclude similar characters' option removes ambiguous characters (0 and O, 1 and l and I) that can be misread when copying passwords manually — useful when you must type the password without copy-paste.