Regex Tester & Validator

This regex matches strings of 2 to 11 characters that may contain spaces, English letters (uppercase or lowercase), digits, underscores, and hyphens, but must include at least one letter. It is commonly used for validating usernames, nicknames, or short display names where a mix of alphanumeric characters and simple separators is allowed, but purely numeric or symbolic inputs are rejected. The lookahead at the start enforces the presence of a letter, while the character class and length quantifier restrict the allowed characters and total length.