Question 1

Which regex flavor does it use?

Accepted Answer

JavaScript regular expressions (the RegExp engine). Patterns behave exactly as they would in JavaScript code.

Question 2

What do the flags do?

Accepted Answer

g finds all matches, i ignores case, m makes ^ and $ match at line breaks, s lets . match newlines, u enables full Unicode handling, and y (sticky) anchors matches at the last index.

Question 3

Can I see capture groups?

Accepted Answer

Yes. Each match lists its captured groups and the index where it starts, so you can confirm the pattern collects the right substrings.

Question 4

Can I share or save my regex?

Accepted Answer

Yes. The pattern, flags, and test string are stored in the page URL, so you can bookmark it or send the link to someone else.

Question 5

Does it send my text anywhere?

Accepted Answer

No. The regex runs entirely in your browser, so your pattern and test text stay on your device.

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