How to test a regular expression in 3 easy steps
- 1
Enter your pattern
Type the regex pattern without slashes, e.g. \d{3}-\d{4}. Add flags like g (global), i (case-insensitive), or m (multiline).
- 2
Add test text
Paste the text you want to search. All matches are highlighted and listed with their capture groups.
- 3
Refine until it matches
The match count and highlights update as you type. Use the preset patterns as a starting point for common cases.
Why use the regex tester tool from Super Utility Hub?
Test and debug regular expressions without firing up a console. Type a pattern and flags, add sample text, and the regex tester highlights every match live, lists each match with its capture groups, and shows the total match count.
This is the fastest way to iterate on patterns for form validation, search-and-replace, log parsing, or scraping rules. Common patterns — email, phone, URL, dates — are available as one-click presets to get you started.
Everything executes locally in your browser with JavaScript's standard RegExp engine, so results match exactly what your code will do. Free and unlimited.
- Processes everything in your browser — no upload servers involved
- Free forever with unlimited uses
- Works on Windows, macOS, Linux, Android and iOS
- No watermark or branding on your output, ever
Frequently asked questions
Which regex engine does the tester use?
JavaScript's standard RegExp engine — exactly what runs in browsers and Node.js. If it matches here, it matches in your code.
What are capture groups?
Parentheses in a pattern create groups that capture parts of a match. The tester lists each group's content per match so you can verify what you're extracting.
What do the g, i, m flags do?
g finds all matches instead of just the first; i ignores case; m makes ^ and $ match line starts and ends. The tester applies exactly the flags you select.
Can I test lookaheads and backreferences?
Yes, JavaScript supports lookaheads, lookbehinds, and named groups — all work in this tester exactly as they do in modern browsers.