Random String Generator

What Is a Random String Generator?

A random string generatorcreates sequences of characters using cryptographically secure randomness — suitable for API keys, session tokens, passwords, PINs, and any other use case where true unpredictability matters. Our tool uses the browser's Web Crypto API, the same standard used by professional security software, and runs entirely in your browser with nothing sent to any server.

How to Generate Random Strings

1. Select a character set — Mixed for passwords and secrets, Alphanumeric for tokens, Letters for readable identifiers, or Numbers for PIN codes.
2. Set the string length — 1 to 1000 characters. Use 32–64 for API keys, 12–16 for passwords, 4–6 for PINs.
3. Choose a count — generate 1 to 50 strings at once for bulk use cases.
4. Apply formatting — split into hyphen or space-separated groups for readability, or leave unformatted for programmatic use.
5. Click Generate — hover any result to copy it, or use Copy All to export the full batch.

Where Can You Use Random Strings?

Character Sets Available

• Mixed Characters — Letters + numbers + symbols. Maximum entropy per character — ideal for passwords, API secrets, and encryption keys. Example: a8fj2L9ke2X@.
• Alphanumeric — Letters + numbers only. URL-safe and copy-friendly — perfect for session tokens, user IDs, and database slugs. Example: a8fj2L9ke2X4.
• Letters Only — Uppercase + lowercase letters. Human-readable strings for test data, identifiers, and readable codes. Example: aFjkLqKeXmPo.
• Numbers Only — Numeric digits. For PINs, SMS verification codes, and numeric identifiers. Example: 847293651024.

Best Practices and Limitations

Use Mixed for maximum security, Alphanumeric for URL-safe tokens. For programmatic use in code or config files, always choose No Format — formatted strings with hyphens/spaces are for human readability only and should be stripped before use in code.

Limitations: The entropy bar reflects the theoretical maximum for the chosen character set and length. When "Exclude Similar" is enabled, the actual pool shrinks slightly (5 characters removed) and entropy is recalculated accordingly. All strings are generated using crypto.getRandomValues() — equivalent to NIST-standard cryptographic randomness.