Regex Tester
Test regular expressions with real-time match highlighting, capture groups, and preset patterns.
How to Test Regular Expressions
Enter your regex pattern in the pattern field, select your flags (global, case-insensitive, multiline), and type or paste your test string below. Matches highlight in real time as you type, so you can refine your pattern iteratively. The match panel shows each match along with its index and any captured groups. If your regex has an error, the tool displays a clear error message. Use the preset buttons to quickly load common patterns for emails, URLs, phone numbers, and more — then customize them for your specific use case.
Why Use an Online Regex Tester?
Regular expressions are powerful but notoriously tricky to get right. An interactive tester gives you instant visual feedback that is much faster than running test scripts. The real-time highlighting shows exactly what your pattern matches (and what it misses), while the capture group panel helps you extract the right substrings. This tool uses the JavaScript regex engine, which is the same engine that runs in browsers and Node.js. All testing happens locally in your browser — your test data never leaves your device.