Regex Tester
Test regular expressions with real-time matching and highlighting
//
Matches will appear here...
How to Use
Enter your regex pattern and flags at the top. Paste your test string below. Matches are highlighted in real-time with detailed information showing match text, index, and capture groups.
Features
- Real-time regex matching as you type
- Visual highlighting of all matches in the test string
- Detailed match information with index positions
- Support for all JavaScript regex flags (g, i, m, s, u)
- Capture group display
Frequently Asked Questions
What is a regular expression?
A regular expression (regex) is a pattern that describes a set of strings. Regexes are used for searching, matching, and replacing text in programming, data validation, log parsing, and text processing.
Which regex flavor does this tool use?
This tool uses JavaScript's built-in RegExp engine, which supports ECMAScript regex syntax including lookahead, lookbehind, named groups, and Unicode properties.