Regex Editor & Tester

This regex validates Minecraft usernames by matching strings of 2 to 16 characters containing only letters, digits, and underscores, anchored to ensure the entire string conforms. With the multiline flag, ^ and $ match at the start and end of each line, making it suitable for validating multiple usernames in a batch (e.g., one per line), while the global flag finds all matches. Commonly used in form validation, chat filters, or whitelist processing for Minecraft servers.