Regex Editor & Tester

This regular expression matches strings that are between 1 and 14 characters long, containing only alphanumeric characters and underscores. It is often used to validate simple file or folder names, usernames, or identifiers where spaces and special characters are not allowed. Note that while it is titled for Linux folder names, it restricts characters more strictly than Linux actually requires, as it disallows common folder name characters like dots and dashes.