Regex Tester
Test and debug regular expressions with live match highlighting.
Three steps, no reading required.
Write your pattern
Type your regular expression between the slashes and set flags like g, i, m.
Add test text
Paste the text you want to match against into the test pane.
Read the matches
Matches highlight live and capture groups are listed below — then copy them.
Try it with a sample.
/\b[\w.+-]+@[\w-]+\.[\w.-]+\b/g Contact us at [email protected] or [email protected].
/#(?:[0-9a-fA-F]{3}|[0-9a-fA-F]{6})\b/g
Brand blue is #2563EB, accent green #22C55E, short form #abc.Test text goes to the server
- Sends your pattern and sample text off-device
- Uses a different regex engine than your code
- Match results only after you press a button
The engine your JavaScript uses
- Native ECMAScript matching (g, i, m, s, u flags)
- Matches highlight live as you type; capture groups listed
- Nothing you enter is uploaded or stored
Questions worth answering upfront.
No. Matching runs entirely in your browser using the native JavaScript regex engine. Nothing you enter is uploaded or stored.
It uses the JavaScript (ECMAScript) regular expression engine, including flags like g, i, m, s and u.
Yes. Matches are highlighted in your test text as you type, and capture groups are listed for inspection.
Yes. Common patterns such as email, URL and date are available to start from and adapt.
g finds every match instead of stopping at the first, i ignores case, m makes ^ and $ match at the start and end of each line, and s lets . match newlines. Type them in the flags box next to the pattern and the highlighting updates.
* matches the preceding token zero or more times, + one or more times. So ab*c matches ac and abbc, while ab+c needs at least one b and does not match ac.
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