ToolerCat / Regex Tester & Explainer

Regex Tester & Explainer

Live matches, capture groups, a token-by-token explanation — and an AI that writes the regex from a plain-English description.

Regular expression

Flags

Library

Test text

Matches highlighted

Matches & groups

#	Match	Index	Groups

Explanation

Replace with (optional, $1 for groups)

Or describe what you want to match

FAQ

Which regex flavor is used?

JavaScript (ECMAScript) regular expressions, the same as in browsers and Node.js. Most syntax is shared with Python, Java and PCRE, but lookbehind and named-group syntax can differ slightly.

What do the flags mean?

g global (all matches), i ignore case, m multiline (^ and $ per line), s dot matches newline, u unicode, y sticky.