Regex Tester & Validator

Matches a username consisting of 3 to 20 characters, allowing letters (a-z), digits (0-9), hyphens, and underscores. It also supports Spanish special characters like ñ and accented vowels (áéíóúÁÉÍÓÚ), making it ideal for Spanish-language applications. The case-insensitive flag ensures both uppercase and lowercase letters are accepted. Typically used for validating user registration or login form input.