About the Regex Tester
Build and debug regular expressions against real text. Matches are highlighted as you type, and a table lists every match with its position and capture groups (including named groups). A quick reference reminds you of common syntax.
The tool uses your browser's JavaScript regex engine, so behaviour matches what your code will do in Node.js and browsers.
How to use it
- Enter the pattern (without slashes) and flags.
- Paste test text.
- Inspect highlighted matches and groups.
Good to know
- Results are limited to the first 1,000 matches for responsiveness.
- Other engines (PCRE, Python, Java) differ in features such as lookbehind and possessive quantifiers.