Regex Editor & Tester

This regex matches HTTP or HTTPS URLs and domain strings ending with `.host.` followed by a TLD, or just `host.` followed by a TLD. It captures the protocol prefix (or a single leading alphanumeric character) in the first group and the domain pattern in the second. It's useful for validating or extracting URLs associated with 'host' domain structures. The multiline flag allows matching across multiple lines of input.