Regex Tester

Write a pattern, paste some test text, and watch every match light up in real time. This regex tester uses the JavaScript regular expression engine — the exact same one that will run your pattern in Node.js or the browser — so what matches here is what matches in production.

All the standard flags are available: global, case-insensitive, multiline, dotAll, unicode and sticky. Below the highlighted text you get a structured list of every match with its index plus the contents of each capture group, which is invaluable when you are extracting data rather than just validating it.

Regular expressions are notoriously easy to get almost right. The classic failure mode is a pattern that works on the example you tested and silently fails on the edge case you didn't — an empty string, a multiline input, a unicode character. Iterating live against realistic sample text is the fastest way to catch those problems early. Your pattern and test text stay entirely in your browser; nothing is uploaded or logged.