What regex flavor does this tester use?

This tester uses JavaScript's native RegExp engine, the same flavor used in Node.js, Chrome, Firefox, and all modern browsers.

How do I test multiline patterns?

Enable the 'm' flag (multiline) to make ^ and $ match line boundaries. Enable the 's' flag (dotAll) to make '.' match newlines too.

Capture groups (...) extract specific parts of a match. Named groups use (? ...) syntax and appear in the results by name.

Test, extract, replace, and explain regular expressions.

Regular Expression

Test String

Matches

No matches found

\d - Digit

\w - Word character

\s - Whitespace

. - Any character

* - 0 or more

+ - 1 or more

? - 0 or 1

^ - Start of string

$ - End of string

Free online regular expression tester. Test regex patterns against strings in real-time, see highlighted matches, and explore common regex patterns.