Which regex flavor does this use?

JavaScript (ECMAScript) regular expressions — the flavor used in browsers and Node.js. Most syntax carries over to other languages, but lookbehind, named groups, and Unicode escapes vary by flavor and version.

What do the g, i, m, s flags mean?

g finds all matches instead of the first; i ignores letter case; m makes ^ and $ match at line breaks; s lets the dot (.) also match newlines.

Regex Tester

Build and debug JavaScript regular expressions interactively. Type a pattern and flags, paste test text, and see every match highlighted in place with a detailed list of match positions and capture groups. Invalid patterns show the exact syntax error instead of failing silently.

Developer Tools

Pattern (without surrounding slashes)

g — globali — ignore casem — multilines — dot matches newline

Test text

No matches.

Private by default

This tool runs entirely in your browser. Your data is never uploaded to a server.

How to use

3 clear steps.

Enter your regular expression pattern (without surrounding slashes).
Toggle flags: global, ignore-case, multiline, dot-all.
Paste sample text and inspect highlighted matches and groups.

Good to know

Frequently asked questions

Which regex flavor does this use?: JavaScript (ECMAScript) regular expressions — the flavor used in browsers and Node.js. Most syntax carries over to other languages, but lookbehind, named groups, and Unicode escapes vary by flavor and version.
What do the g, i, m, s flags mean?: g finds all matches instead of the first; i ignores letter case; m makes ^ and $ match at line breaks; s lets the dot (.) also match newlines.