Regex Tester & Debugger
Test regular expressions live with real-time matching, capturing groups breakdown, flag controls, and string substitutions.
Regular Expression & Flags
Test String Input
Substitution / Replacement
Optional// Replacement preview will appear here...
Live Match Highlights
Match Breakdown & Groups
0 matches foundAbout the Regex Tester & Debugger
Easily build, validate, and troubleshoot complex regular expressions for programming and data extraction.
Regular Expressions (Regex) provide a powerful syntax for pattern matching and string searching in text. Our Regex Tester & Debugger lets you experiment with patterns live, inspect capturing groups breakdown, check modifiers, and preview substitutions safely in your web browser.
Live Visual Matching
Instantly highlights matched strings, overlapping patterns, and partial sub-matches within your target text block in real-time.
Capturing Groups Breakdown
Deconstructs every regex match into numbered sub-groups, capturing offsets, token lengths, and indexes clearly.
Advanced Flag Controls
Toggle global (`g`), case-insensitive (`i`), multiline (`m`), dotall (`s`), and unicode (`u`) flags on the fly with live evaluation.
String Substitution Mode
Test search-and-replace patterns instantly using group references like `$1` and `$2` for quick refactoring workflows.
Built-in Common Presets
Instantly load production-ready standard patterns for Emails, URLs, Hex Colors, Phone Numbers, and Dates.
100% Private & Secure
Everything executes client-side inside your browser sandbox. Your proprietary strings and logs never touch external servers.