Free Regex Tester
Test regular expressions with live matching, highlighting, and capture groups. Free, no signup.
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How to Test Regular Expressions Online
Enter your regex pattern and test string above. Matches are highlighted in real time as you type. The match table shows each match with its index position and capture groups. Toggle flags to control matching behavior.
Why Use Our Regex Tester?
Writing and debugging regular expressions is notoriously difficult. Our tester provides instant visual feedback with highlighted matches, capture group display, and flag toggles — all running in your browser with zero latency. Perfect for developers, data engineers, and anyone working with text patterns.
Frequently Asked Questions
What regex flavor does this use? JavaScript (ECMAScript) regular expressions, which is what runs in browsers and Node.js.
What do the flags mean? g = find all matches (not just first), i = case-insensitive, m = multiline (^ and $ match line boundaries), s = dotAll (. matches newlines).
Is my data sent to a server? No. All matching happens locally in your browser using native RegExp.