Password Generator — Create Strong Random Passwords

This free password generator creates strong, random passwords using crypto.getRandomValues(), the browser's cryptographically secure random source. Password strength is measured in bits of entropy, and length contributes more than fiddly composition rules — a 16-character random password carries well over 100 bits, far beyond brute-force reach. Choose your length and character set, or generate a memorable passphrase of random words. Nothing is transmitted or stored; the password exists only on your device, so it is safe to generate and copy here.

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How passwords are generated

This generator uses the browser's crypto.getRandomValues() API — a cryptographically secure pseudorandom number generator (CSPRNG) backed by the operating system's entropy source. This is the same randomness source used by cryptographic libraries, making generated passwords resistant to prediction.

The character pool is assembled from your selected options: uppercase letters (26), lowercase letters (26), digits (10), and symbols (~32 printable ASCII symbols). A random index is drawn from the full pool for each character position. Password strength grows exponentially with length: an 8-character password using all character types has 948 ≈ 6 × 1015 combinations; a 16-character password has 9416 ≈ 3.7 × 1031. At 1 trillion guesses per second, cracking a 16-character random password would take over a trillion years. The generated password is never sent anywhere — all generation is local. Use a password manager to store and autofill generated passwords.

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Entropy beats complexity rules

Password strength is measured in bits of entropy — the base-2 logarithm of how many equally likely passwords could have been generated. Each random character from a 94-symbol set adds about 6.5 bits, so a 16-character random password carries ~104 bits, far beyond brute-force reach. Length contributes more than fiddly composition rules: a longer all-lowercase string usually beats a short one peppered with symbols.

Why passphrases work

Four or five random words (the "correct-horse-battery-staple" idea) reach 50–65 bits of entropy while staying memorable — strong enough for accounts you must type by hand. For everything else, a password manager storing unique 20-character random strings per site is the gold standard, because reuse, not weakness, causes most account takeovers.

Generated safely in your browser

This tool draws from crypto.getRandomValues(), a cryptographically secure source, and never transmits or stores what it produces — the password exists only on your device. Avoid predictable substitutions like P@ssw0rd; attackers' wordlists already include every common leetspeak variant.

⚠️ Common Mistakes to Avoid

Frequently asked questions

Is this generator secure?

Yes, passwords are generated locally in your browser and are never sent to our servers.

How long should a password be?

Security experts recommend at least 12 characters, but 16 or more is significantly stronger against brute-force attacks.

Reviewed by the ToolsmithPro editorial team · Last updated June 2026. Every calculation and conversion runs entirely in your browser — your inputs are never uploaded, stored or shared. Formulas and methodology are documented on our about page; spot an error? tell us and we'll fix it.