Password Generator — Strong Passwords

1. What does this tool do

This free online password generator creates strong passwords in your browser. Use presets (alphanumeric, PIN, hex, passphrase) or a custom character set and an optional pattern (e.g. 4 letters + 4 digits). With Custom format, when you define a pattern, your custom character set is used for every position (customer defined format). No sign-up, no server. All generation uses crypto.getRandomValues() (CSPRNG). For SESSION_SECRET and API keys, use the Secret Generator tool (Developer category).

2. How to use it

Quick start: Choose a format (e.g. Alphanumeric, Passphrase, or Custom), set length or word count, optionally enter a pattern (L = letter, D = digit, S = symbol; for PIN or Hex use only D). Click Generate passwords and copy.

1. Format — Choose a preset (Alphanumeric, Letters+numbers+symbols, PIN, Hex, Passphrase, or Custom). Set length (or for passphrase choose By word count or By pattern). For passphrase By pattern: use space-separated segments; W = word from list, L = letter, D = digit, S = symbol (e.g. W W DDD W). You can tick Use one pattern for all words and set a single segment (e.g. W) plus word count. For other presets, optionally set a pattern (e.g. LLLLDDDD). For PIN or Hex, use only D in the pattern (e.g. DDDDDD).
2. Custom format — Select Custom and type your own character set (e.g. abc123!@#). Use at least 2 different characters. If you also set a pattern, the pattern length is used and each position is filled from your custom set (your defined format).
3. Count — Set how many passwords to generate (1–10). Click Generate passwords and copy.

3. How it works

All randomness comes from the Web Crypto API (crypto.getRandomValues()). No Math.random() is used. Passwords are built by sampling from the chosen character set (or from L/D/S sets when using a pattern with a preset; with Custom + pattern, the custom set is used for every position). Passphrases pick words from a fixed EFF-style wordlist. All computation is client-side (BR-010); nothing is sent to a server.

4. Use cases & examples

• Passwords — Alphanumeric 16, PIN 6, or passphrase (by word count or by pattern, e.g. 4 words or W W DDD W) for accounts or apps.
• Custom / customer defined — Custom charset and pattern (e.g. 8 chars from abc123) for site-specific rules.
• Pattern with preset — e.g. LLLLDDDD with Alphanumeric for 4 letters + 4 digits; with PIN use DDDDDD only.
• Custom rules — Custom charset (e.g. digits + symbols only) or pattern LLLLDDDD for “4 letters + 4 digits”.

Example

• Alphanumeric 16 → e.g. Kp9mN2xRqL7vYwZ4.
• Passphrase 4 words (By word count) → e.g. cabin almond oasis guitar. Passphrase By pattern W W DDD W → e.g. cabin almond 712 guitar.
• Custom set ab12 with pattern length 6 → e.g. a2b1ab.

5. Limitations & known constraints

• Length limits — Single password length is capped (e.g. 256 characters).
• Count — Up to 10 passwords per generation.
• Browser support — Requires crypto.getRandomValues(). Available in all modern browsers.
• No persistence — Generated values are not stored; copy them if you need to keep them.