Regex Tester

Regex Tester runs a regular expression against a block of text using your browser's own JavaScript regex engine and highlights every match, including any capture groups.

Reach for this while writing or debugging a pattern, to quickly check it against real example text instead of testing it inside whatever script or application it will eventually run in.

This uses JavaScript's regex flavor specifically. Other languages have their own regex dialects with small but real differences, so a pattern tested here is not guaranteed to behave identically in, for example, Python or PHP.