Regex Tester & Validator

Matches URLs starting with http://, https://, or www., capturing the scheme (with optional 's'), the domain (optional www. prefix plus a TLD of 2-4 alphanumeric chars), and any trailing path/query characters. The (*SKIP) verb forces the match to fail cleanly if a scheme is present but the rest doesn't match, while the conditional makes the www. prefix mandatory only when no :// precedes it. Ideal for linkifying plain-text URLs into clickable HTML links in user-generated content.