Test regular expressions with live feedback
Regular expressions are powerful but unforgiving — a single character changes what matches. Rather than guess and re-run your program, this tester lets you build a pattern and see, instantly, what it matches against sample text. Matches are highlighted as you type, so you can refine the pattern until it catches exactly what you want and nothing you don't.
How to use it
- Enter your regular expression and any flags.
- Paste sample text to test against.
- Watch the matches highlight, and adjust the pattern until it's right.
Tips
- Start broad, then tighten — it's easier to narrow a pattern than to debug a complex one.
- Use the global flag to find every match, not just the first.
- Escape characters like
.and?when you mean them literally.
Questions people ask
Which regex dialect does it use? JavaScript's, which closely matches the syntax used in many other languages for everyday patterns.
Is my text sent anywhere? No — matching runs locally in your browser.