Regex Tester Online
Test and debug regular expressions with real-time highlighting. Free, fast, and runs 100% in your browser.
Regular expressions are powerful but notoriously hard to debug without visual feedback. This tester highlights matches in real time as you type your pattern and test string. Toggle flags for global, case-insensitive, and multiline matching. See capture groups, match positions, and learn regex syntax through immediate visual feedback.
hello@example.comsupport@company.orgadmin@test.co\\d+ — Digits\\w+ — Word chars[a-zA-Z]+ — Letters\\b\\w+@\\w+\\.\\w+\\b — Email^https?:// — URL start\\d{3}-\d{3}-\d{4} — PhoneFeature Overview
| Feature | Details |
|---|---|
| Real-time matching | ✓ |
| Flag toggles | g, i, m |
| Capture groups | ✓ |
| Match highlighting | Color-coded |
| Privacy | 100% client-side |
Frequently Asked Questions
What regex engine does it use?
JavaScript's native RegExp engine, which supports character classes, quantifiers, lookaheads, lookbehinds, capture groups, and named groups.
Can I test regex for form validation?
Absolutely. Build and test email, phone, URL, and custom validation patterns before implementing them in your application.
Does it show capture groups?
Yes. Each match displays its numbered and named capture groups so you can verify extraction patterns.