Generate Random Alphanumeric

randomAlphaNumeric

The randomAlphaNumeric function generates a random alphanumeric string (letters and numbers) of the specified length.

Function Signature

randomAlphaNumeric(length?: number, uppercase?: boolean): string

Parameters

Return Value

Returns a randomly generated alphanumeric string composed of letters and numbers of the specified length.

Example Usage

Use Cases

• Generating unique identifiers
• Creating random tokens for authentication or password resets
• Generating temporary session IDs
• Generating readable codes or reference keys

Implementation Notes

• The function generates random bytes and converts them to base-36 (0-9, a-z) characters.
• If length is 0 or negative, an empty string is returned.
• Uses crypto.getRandomValues (via randomBytes) when available for secure randomness, and falls back to Math.random if not.
• The uppercase parameter controls whether the letters are uppercase or lowercase. By default, it returns lowercase letters.

See Also

• randomHex - Generate cryptographically secure random hex strings
• randomBytes - Generate cryptographically secure random bytes (Uint8Array)
• randomNumeric - Generate cryptographically secure random numeric strings
• randomID - Generate customizable random alphanumeric ID (cryptographically not secure)