Regex Tester
Test regular expressions against sample text. See all matches highlighted inline with capture groups listed. Supports all JavaScript regex flags. Runs in your browser.
Frequently Asked Questions
Which regex flavour does this tester use?
JavaScript's built-in RegExp engine. This matches how regexes work in Node.js, browsers, and TypeScript. Most common patterns work the same across flavours, but lookahead, named groups, and some character classes may differ from Python or PCRE.
What flags are supported?
g (global — find all matches), i (case-insensitive), m (multiline — ^ and $ match line boundaries), and s (dotAll — dot matches newlines). You can combine multiple flags.
How are capture groups shown?
Each match is listed with the full match and any capture groups numbered from 1. Named groups ((?<name>...)) are shown with their names.
Is my data private?
Yes — completely. Everything runs locally in your browser. Nothing is sent to any server, and nothing is retained after you close the tab.
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