Regex Tester & Validator

This regular expression is designed to extract the domain name from a given URL string. It effectively handles optional protocols (HTTP/HTTPS), optional authentication details, and optional 'www.' prefixes before capturing the core domain in the first capturing group. The `igm` flags ensure it processes multiple lines independently, matches case-insensitively, and finds all occurrences. It is highly useful for web scraping, log parsing, and data normalization where domain extraction is required.