Regex Tester
Test regular expressions against any string with live match highlighting. All processing is in-browser.
Pure browser JavaScript — uses the built-in RegExp engine.
How to use this tool
- Enter a pattern (e.g. \b\w+\b).
- Set flags (g=global, i=case-insensitive, m=multiline).
- Type a test string — matches highlight in real time.
Test regular expressions against any string with live match highlighting. All processing is in-browser.
Frequently asked questions
- Which flags are supported?
- g (global), i (case-insensitive), m (multiline), s (dotAll), u (unicode), y (sticky) — the full JavaScript RegExp flag set.