Password Generator
Generate cryptographically secure passwords and check strength instantly. Runs entirely in your browser — your password never leaves your device. Free, no account.
Password Security Lab
Generate cryptographically secure passwords and measure their crack-resistance.
Entropy Score
EmptyEstimate: Can be cracked in minutes
Privacy First: This tool runs entirely in your browser. Your generated passwords never touch a server. We don't log or store anything.
What Is a Password Generator?
A password generator creates a random, unpredictable string of characters for use as a password or security credential. A strong generator uses a cryptographically secure random source — this tool uses the browser's native crypto.getRandomValues() API — to ensure the output is truly random and not reproducible from a predictable seed.
This tool also checks the strength of any password you paste in, giving you a real-time entropy score based on the character set used and the length. Whether you're generating a new password or auditing an existing one, you get an objective measure of how strong it actually is.
How to Use the Password Generator
- Set your password length. Choose how many characters you want. 16 characters is a good default for most accounts; use 20+ for email, banking, and password manager master passwords.
- Select character types. Toggle uppercase, lowercase, numbers, and symbols. Including all four maximizes entropy and makes the password harder to crack by brute force.
- Generate your password. Click Generate. The tool uses
crypto.getRandomValues()to produce a truly random string — not a pseudo-random pattern. Regenerate as many times as you want at no cost. - Copy and save it. Copy the password and store it in your password manager immediately. Don't save it in a plain text file or email.
Who Is This For?
- Anyone setting up a new account who wants a strong password instantly. Instead of thinking of something "clever" (which usually means guessable), generate a genuinely random password and let your password manager remember it.
- Security-conscious users who want to verify their generator is truly random. This tool is transparent about its method —
crypto.getRandomValues()— so you can confirm the randomness source yourself. - IT and security teams generating temporary credentials or API keys. The entropy score helps verify a generated string meets your organization's minimum security requirements before deployment.
Key Benefits
- Privacy — your password never leaves your device. The tool runs entirely in your browser. No network call is made, no password is logged, and no data is stored. You can run it offline to confirm.
- Free. No subscription, no paywall, no account needed.
- No account required. Open the tool, generate, copy, done.
- Cryptographically secure randomness. Uses
crypto.getRandomValues(), the same API used by browsers for TLS — notMath.random(), which is not cryptographically secure.
Common Use Cases
A developer sets up a new staging environment and needs a secure random string for the database password. They generate a 24-character password with all character types, copy it into their .env file, and save it to their team password manager.
Someone signing up for a new banking account wants a password stronger than anything they'd come up with themselves. They generate a 20-character password, save it to 1Password, and never have to think about it again.
A security engineer is auditing employee passwords after a credential stuffing incident. They paste flagged passwords into the strength checker to identify which ones fall below the 80-bit entropy threshold the company requires.
A small business owner migrating their team to a password manager uses the generator to create strong unique passwords for every shared account before importing them.
A Note on Privacy
Unlike many "online password checkers," this tool runs entirely inside your browser. No password is sent to a server, no input is logged, and nothing is stored. You can verify this by disconnecting from the internet — the tool will still work, which confirms no network call is made.
3 Tips for Managing Secure Passwords
- Use a password manager. You shouldn't have to memorize a 20-character random string. Tools like Bitwarden (free), 1Password, or iCloud Keychain store your passwords securely so you only need to remember one master password.
- Enable multi-factor authentication. MFA is your second line of defense. Even if someone obtains your password through a data breach, MFA prevents them from accessing your account.
- Check for breaches. A strong password is useless if the service you use it on gets compromised. Use tools like Have I Been Pwned to monitor whether your accounts have appeared in known data breaches.
Frequently Asked Questions
What is a password generator? ▼
A password generator creates a random, unpredictable string of characters for use as a password. A strong generator uses a cryptographically secure random source — this tool uses the browser's native crypto.getRandomValues() API — to ensure the output is truly random and not guessable.
Is it safe to generate a password in a browser tool? ▼
Yes, if the tool is client-side. This tool uses the browser's native crypto.getRandomValues() API and never transmits your password to any server. You can verify this by disconnecting from the internet and running the tool — it works offline, which confirms no network call is made.
What makes a password secure? ▼
Length is the most important factor — a 16-character random password is exponentially harder to crack than an 8-character one. A mix of uppercase, lowercase, numbers, and symbols also helps by expanding the character pool an attacker has to guess from. Avoid dictionary words, names, and predictable patterns like "qwerty" or "123456".
How long should a password be? ▼
Use a minimum of 12 characters for most accounts and 16+ characters for email, banking, and password manager master passwords. Length matters more than complexity — a 20-character lowercase-only password is stronger than an 8-character password with symbols.
What is password entropy? ▼
Entropy is a mathematical measure of a password's unpredictability, expressed in bits. The higher the entropy, the more guesses an attacker needs to crack the password by brute force. A 16-character password using the full character set (uppercase, lowercase, numbers, symbols) has roughly 105 bits of entropy — effectively uncrackable with current technology.
Should I use a password manager with generated passwords? ▼
Yes. A 20-character random password is impossible to memorize, and that's the point — you shouldn't need to. Store generated passwords in a password manager like Bitwarden, 1Password, or iCloud Keychain. You only need to remember one strong master password.
The tools and calculators provided on The Simple Toolbox are intended for educational and informational purposes only. They do not constitute financial, legal, tax, or professional advice. While we strive to keep calculations accurate, numbers are based on user inputs and standard assumptions that may not apply to your specific situation. Always consult with a certified professional (such as a CPA, financial advisor, or attorney) before making significant financial or business decisions.
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