Regex Tester
Test regular expressions live with highlighted matches, capture groups and flags.
About Regex Tester
Build and debug JavaScript regular expressions interactively. Type a pattern, toggle flags, and see every match highlighted in your test string along with capture groups and positions. Runs entirely in your browser.
How to use Regex Tester
- 1
Enter your regular expression pattern.
- 2
Toggle the flags you need (global, ignore case, multiline, etc.).
- 3
Paste the text you want to test against.
- 4
See matches highlighted live, with a list of groups and positions.
Frequently Asked Questions
Which regex flavor is this?
JavaScript (ECMAScript) regular expressions, using your browser's built-in RegExp engine.
Does it show capture groups?
Yes. Each match lists its captured groups and the index where it was found.