Strong Password Generator
Generate highly secure passwords instantly with full control over all character types. Our tool ensures your generated password meets the highest security standards by guaranteeing the inclusion of selected character sets.
Select which character types to include - uppercase, lowercase, digits, symbols - and drag the length slider up to 50 characters. The generator guarantees at least one character from each selected category, then fills the rest randomly using crypto.getRandomValues(). A live entropy meter shows the strength in real time.
Use the Tool​
Click Generate to start
Customize Password
*Generated password length is limited to 50 characters by the API.
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What This Tool Does​
What the tool does​
A client-side password generator that builds a random string from your chosen character sets and guarantees at least one character from each active category. All generation runs directly in your browser via the Web Crypto API (crypto.getRandomValues), so no password data ever touches a server.
What problems it solves​
Humans are poor sources of randomness - we gravitate toward dictionary words, birthdays, and keyboard walks like qwerty123. Reusing weak passwords across sites means a single breach compromises every account. This tool removes human bias entirely, producing passwords with no exploitable pattern. The strength meter gives you immediate feedback so you can see exactly when your settings cross from weak into practically uncrackable.
Who should use it​
- Anyone creating a new account without a password manager
- Developers generating credentials for test accounts or staging environments
- Sysadmins setting initial passwords for new users before forcing a change
- Anyone auditing and replacing old, reused, or dictionary-based passwords
Why it matters​
Password entropy is calculated as $E = L \times \log_2(N)$, where $L$ is the length and $N$ is the size of the character pool. A 12-character lowercase-only password has $N = 26$, giving $E \approx 56$ bits - crackable in hours on modern hardware. Add uppercase + digits + symbols ($N = 94$), and the same length yields $E \approx 79$ bits, pushing brute-force time into centuries at the same attack rate. This tool's default settings target ≥ 72 bits of entropy, meeting the NIST SP 800-63B memorized secret recommendations.
How It Works​
Input​
Use the checkboxes to select which character pools to include (uppercase A–Z, lowercase a–z, digits 0–9, symbols such as !@#$%^&*) and the slider to set the desired length (1–50). At least one character type must be active.
Processing​
The generator uses crypto.getRandomValues() - the browser's CSPRNG, backed by the OS entropy pool - to select characters. It first guarantees one character from each active category by sampling each pool independently, then fills the remaining positions from the full combined pool. The result is shuffled with a Fisher-Yates algorithm also seeded via crypto.getRandomValues(), preventing the guaranteed characters from clustering predictably at the start.
Limitations​
- 50-character cap - sufficient for virtually all services. For longer secrets such as JWT signing keys, use the JWT Secret Key Generator.
- No spaces - intentionally excluded, as many password fields and clipboard tools strip or reject them.
- No passphrase mode - this tool produces character-random strings, not word-based passphrases like
correct-horse-battery-staple.
Output​
The password appears in a masked field with a reveal toggle. The strength meter below it shows an estimated entropy label (Weak / Fair / Strong / Very Strong). Click "Copy" to write the password to the clipboard - the field stays masked until you explicitly reveal it.
Security Disclosure​
CSPRNG used: crypto.getRandomValues() - the Web Crypto API built into every modern browser. This is backed by the operating system's entropy pool (equivalent to /dev/urandom on Linux, CryptGenRandom on Windows). It is not Math.random(), which is a deterministic PRNG unsuitable for cryptographic use.
Client-side only: No password data, no character set selections, and no generated strings are transmitted to any server at any point. The entire generation pipeline runs in your browser's JavaScript engine. You can verify this by opening DevTools → Network and observing zero outbound requests when clicking Generate.
What this tool does not do:
- Does not store passwords in
localStorage,sessionStorage, or cookies - Does not log generation events or character set choices
- Does not use analytics that could capture form field values
Entropy guarantee: The Fisher-Yates shuffle used to randomise the final character order is also seeded via crypto.getRandomValues() - not Math.random(). This prevents the guaranteed category-fill characters from appearing in a predictable position (e.g., always first).
Last reviewed: May 2026 by Serhii Hrekov - Full-stack developer with focus on security tooling and privacy-first web applications.
Frequently Asked Questions​
Is it safe to generate passwords on this website?​
Yes. The password generation process runs entirely in your web browser (client-side) or via a secure stateless API that does not store your data. We never save, log, or transmit the passwords you generate.
How long should my password be?​
For decent security, we recommend a minimum length of 12-16 characters. For critical accounts (like banking or email), 20+ characters is even better.
Why do I need special characters?​
Special characters (like @, #, $, %) increase the "entropy" or randomness of your password, making it exponentially harder for hackers to guess or crack using brute-force attacks.
Can I retrieve a password I generated earlier?​
No. Since we do not store any passwords, once you close the page or generate a new one, the previous password is gone forever. Please save it immediately in a secure password manager.
Why doesn't the generator include real words?​
"Random" passwords are mathematically stronger than passwords based on dictionary words (which are vulnerable to "dictionary attacks"). This tool focuses on maximum randomness for security.
Is this tool free to use?​
Yes, this Strong Password Generator is completely free for personal and commercial use.
What if I select all character types but set the length to 3?​
The tool adheres to your length setting first. If the length is too short to include one of every selected type, it will prioritize randomness but may not be able to fit every character type. We recommend a length of at least 8 to ensure a good mix.
Can I use this for my WiFi password?​
Absolutely. Random independent characters make excellent WiFi passwords that are very difficult for neighbors or malicious actors to crack.
Does the strength meter guarantee my password is unhackable?​
No tool can guarantee a password is 100% unhackable. The strength meter is an estimation based on length and complexity (entropy). A "Strong" rating means it would take modern computers a very long time to crack it.
Do I need to install any app?​
No. This tool works directly in your web browser on desktop, mobile, and tablet. No downloads are required.
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