Regex Tester
Write a regex pattern, choose flags, and test against any string with live highlight previews and detailed match results — all computed locally.
Use the regex tester
What is this tool used for?
- Debugging validation patterns for forms and APIs
- Testing capture groups before adding regex to production code
- Learning regex syntax with immediate visual feedback
- Verifying log parsing or search patterns on sample text
Frequently asked questions
- Which regex flavor does this use?
- JavaScript regular expressions (ECMAScript), the same engine used in browsers and Node.js.
- Can I test global and case-insensitive matches?
- Yes. Toggle flags such as global (g), ignore case (i), multiline (m), dotAll (s), and unicode (u).
- Is my test data uploaded?
- No. Matching runs entirely in your browser.
- Why am I seeing an invalid regex error?
- Check for unescaped special characters, unclosed groups, or unsupported syntax for your selected flags.
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