Regex Tester
Test regular expressions with live match highlighting, capture groups, and replace — all in your browser.
100% in your browser. Nothing is uploaded.
Frequently asked questions
Is my test data sent anywhere?
No. All matching runs entirely in your browser using the native JavaScript RegExp engine. Nothing leaves your device.
Which flags are supported?
g (global), i (case-insensitive), m (multiline), s (dotAll — dot matches newline), u (unicode), and y (sticky). Combine them freely; the tool rebuilds the RegExp on every keystroke.
How do named capture groups work?
Use (?<name>...) syntax. Named groups appear in the match list alongside numbered captures. In the replacement input you can reference them as ${name}.
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