🔍 Regex Tester
Test regular expressions with live match highlighting, group capture and a common patterns library.
The Regex Tester is a real-time regular expression debugger for developers, sysadmins and security analysts. As you type your pattern and test string, matches are highlighted inline in the text and listed below with their exact position and any captured groups. This immediate visual feedback makes it much faster to build and debug complex patterns than writing test code in a development environment.
The flags selector lets you toggle between common flag combinations, global, case-insensitive, multiline and combinations of these, which is important because many regex issues are caused by missing flags rather than incorrect patterns. The match list shows each match with its index position, which is useful when you need to understand exactly what was matched and where.
The built-in pattern library covers 20 common IT patterns including IPv4 addresses, IPv6, MAC addresses, CIDR notation, Windows Event IDs, Active Directory usernames, PowerShell EncodedCommand arguments and UUIDs. Click any pattern to load it instantly. These patterns are a practical starting point for log analysis, input validation and security monitoring use cases.