Overview
RegExr is a free, online tool designed to assist developers in learning, building, and testing regular expressions (regex). It supports both JavaScript and PCRE (PHP Compatible Regular Expressions) flavors. The tool offers real-time updating of results as users type their expressions and test strings. Users can roll over matches or expressions to view detailed explanations. RegExr provides a test suite feature to validate patterns, and expressions can be saved and shared with the community. Integrated tools help explore results with options for replacement, listing outputs, and detailing capture groups. The 'Explain' tool translates the expression into plain English. It includes a comprehensive RegEx Reference with examples and offers undo/redo functionality.