Regex Tester & Validator

This regex extracts the value of the utm_campaign parameter from a URL string into a named capture group 'utm_campaign'. It uses a positive lookbehind to locate 'utm_campaign=' and a lazy match that terminates at the next '&', whitespace, or end of line, correctly handling query strings containing multiple parameters. Ideal for marketing analytics, campaign attribution tracking, and parsing URLs in logs or bulk data with Python's re module.