Password Generator
Generate secure passwords and passphrases with customizable options
Details
A cryptographically secure password generator that creates strong, unpredictable passwords using the browser's native Crypto.getRandomValues() API — the same randomness source used by modern operating systems for cryptographic operations. Unlike Math.random()-based generators that produce predictable output, every password generated by this tool passes through a cryptographically secure pseudorandom number generator (CSPRNG). You control every aspect of password generation: set the exact length, toggle uppercase and lowercase letters, include digits, symbols, and extended special characters, and exclude ambiguous characters like 'l', '1', 'O', and '0' that cause confusion. The generator also supports passphrases — memorable sequences of random dictionary words separated by a delimiter of your choice — and numeric PIN codes for simpler use cases. A real-time strength meter visualizes password entropy to help you make informed decisions. The entropy-based strength evaluation follows NIST guidelines, estimating how many guesses an attacker would need on average. All generation happens entirely client-side; no passwords ever leave your browser. Ideal for generating API keys, database credentials, SSL private key passphrases, user account passwords, and any scenario where cryptographic randomness matters.
Examples
Strong Password
Password: Kp9$mN2@xL4c - Length: 12, Mixed case, Numbers, Symbols
Passphrase
Passphrase: correct-horse-battery-staple - 4 words with dashes
PIN Code
PIN: 847392 - 6 digit numeric code
Secure Key
Secure Key: aB3#kL9$pQ2@mN7&xR5% - 20 chars with all character types
Examples
Illustrative 16-character mixed password
Format: 16 characters; lowercase, uppercase, digits, and symbols]=x1&tO7p=JYIS)HIllustrative sample only: a fresh generation should produce a different, non-reproducible value.
Illustrative 24-character alphanumeric password
Format: 24 characters; lowercase, uppercase, and digitsYll19k3Y66G4cMLmBsmU5v2IIllustrative sample only: longer output can compensate for a smaller character pool when a site does not accept symbols.
Illustrative 20-character password without ambiguous characters
Format: 20 characters; ambiguous 0/O/1/I/l excludedymkaEw9eGjBhcnFxy#&pIllustrative sample only: excluding look-alike characters can reduce transcription errors, but every actual password should be newly generated.
About this tool
Weak or reused passwords are the single most common cause of account compromise. A strong password is long and unpredictable — and predictability is exactly where most generators fail, because they rely on Math.random(), which is not designed to be cryptographically secure. This generator instead uses the browser's Crypto.getRandomValues() CSPRNG, the same randomness source operating systems use for cryptographic operations, so every password is genuinely unpredictable.
You control the exact length and character sets — uppercase, lowercase, digits, symbols and extended special characters — and can exclude ambiguous characters like l, 1, O and 0 that cause transcription errors. Nothing is transmitted or stored: passwords are generated and shown entirely in your browser, so they never touch a server.
How to use
Set the length
Choose a length — 16 or more characters is recommended for important accounts.
Pick character sets
Enable uppercase, lowercase, numbers and symbols to widen the pool and increase strength.
Exclude ambiguous characters
Optionally drop look-alike characters (l/1/O/0) for passwords you'll type by hand.
Generate and copy
Generate the password and copy it straight into your password manager.
Use cases
Creating unique passwords for a password manager
Generate a long, site-specific value, save it directly in a password manager, and avoid deriving it from personal information or another account's password.
Meeting service-specific character rules
Adjust length and enabled character sets for a legacy system that rejects certain symbols while keeping the accepted password as long as possible.
Issuing temporary bootstrap credentials
Create a one-time initial credential for an account or device, deliver it over a protected channel, and require replacement at first use.
Reducing manual transcription errors
Exclude ambiguous characters for credentials that must be read from another screen or typed by hand, then compensate with additional length.
Strength factors
| Setting | Effect on strength |
|---|---|
| Length | The biggest factor — each extra character multiplies the possibilities |
| Character sets | More sets (upper/lower/digits/symbols) enlarge the pool per position |
| CSPRNG | Cryptographically secure randomness prevents predictable output |
| Exclude ambiguous | Improves typability at a small cost to the character pool |
Generated locally with Crypto.getRandomValues() — never sent to a server.
Common mistakes
Mistake:Using Math.random() or another non-cryptographic PRNG for passwords.
Fix:Generate password choices from a CSPRNG such as Crypto.getRandomValues(). A value can look random while still being predictable if its source was not designed for cryptographic use.
Mistake:Choosing a short password or shrinking the character pool without adding length.
Fix:Length is the strongest practical control. If symbols must be excluded for compatibility, increase the length so the smaller per-character pool does not unnecessarily reduce entropy.
Mistake:Reusing one generated password across accounts.
Fix:Generate a unique password for every account and store it in a password manager. One breached service should not expose credentials for another.
Mistake:Storing, logging, emailing, or returning a generated password over an unencrypted channel.
Fix:Copy it directly into its destination or password manager, avoid logs and plaintext storage, and use an authenticated encrypted channel for any unavoidable transfer.
Frequently asked questions
Related guides
Caesar Ciphers, ROT13, and Why Neither Is Encryption
What a shift cipher is, why ROT13 is self-inverse and useful for light obfuscation, and how frequency analysis breaks even large keys efficiently.
How BIP39 Seed Phrases Work (and Why You Must Never Reuse One)
The entropy-to-words mapping, the checksum, and the security model that makes a 12-word phrase protect an entire cryptocurrency wallet.
References & standards
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