Regex Editor & Tester

This regular expression matches strings that start with 'www', followed by any character (likely intended as a literal dot), and a domain name between 4 and 64 characters long. The domain name must consist of alphanumeric characters and hyphens but cannot start with a hyphen, and the string must end with the '.co.uk' top-level domain. It is typically used for validating United Kingdom web addresses that explicitly include the 'www' subdomain.