What regex flavor does this use?

JavaScript's native RegExp engine — the same one that runs in every browser and in Node.js. Patterns behave exactly as they would in your own JS code.

What do the flags mean?

g finds all matches instead of stopping at the first; i makes matching case-insensitive; m makes ^ and $ match the start/end of each line instead of the whole string; s makes . also match newlines; u enables full Unicode handling.

Why do I only see one match without the g flag?

That mirrors how JavaScript's regex.exec() behaves — without the global flag, only the first match is returned. Turn on g to find every match in the string.

Are named capture groups supported?

Yes — use the (? ...) syntax in your pattern and the named groups will show up separately from the numbered groups in the match details.

Is my text or pattern sent anywhere?

No. Matching happens entirely in your browser using JavaScript's built-in regex engine.

REGEX TESTER

Test a pattern against a string with live match highlighting. Nothing leaves your browser.

Pattern

//g

Test string

Highlighted matches (2)

Match details

#1 at index 14hello@example.com
Group 1: helloGroup 2: example
#2 at index 35support@dimastoolbox.com
Group 1: supportGroup 2: dimastoolbox

How to test a regular expression

1
Type a regular expression pattern and toggle the flags you need (g, i, m, s, u).
2
Paste or type the text you want to test it against.
3
See every match highlighted live, with capture groups and their positions listed below.

Questions

What regex flavor does this use?: JavaScript's native RegExp engine — the same one that runs in every browser and in Node.js. Patterns behave exactly as they would in your own JS code.
What do the flags mean?: g finds all matches instead of stopping at the first; i makes matching case-insensitive; m makes ^ and $ match the start/end of each line instead of the whole string; s makes . also match newlines; u enables full Unicode handling.
Why do I only see one match without the g flag?: That mirrors how JavaScript's regex.exec() behaves — without the global flag, only the first match is returned. Turn on g to find every match in the string.
Are named capture groups supported?: Yes — use the (?<name>...) syntax in your pattern and the named groups will show up separately from the numbered groups in the match details.
Is my text or pattern sent anywhere?: No. Matching happens entirely in your browser using JavaScript's built-in regex engine.