Regex Tester
Test JavaScript regex patterns against sample text with live match highlighting and capture groups.
Matches: 0
How to use this tool
Type a regex pattern and flags, then paste test text — matches highlight live below, with each match's capture groups listed.
About this tool
Uses JavaScript's native RegExp engine, the same one your browser and Node.js use, so behavior matches exactly what you'd get in real code.
100% client-side. Nothing you type is uploaded, logged, or stored.
Frequently asked questions
Which regex flavor does this use?
JavaScript's native RegExp engine (ECMAScript regex syntax), since this tool runs entirely in your browser. Most features are similar to PCRE, but some syntax (like recursive patterns) is not supported.
What do the g, i, m, s flags mean?
g (global) finds all matches instead of stopping at the first. i (case-insensitive) ignores letter case. m (multiline) makes ^ and $ match the start/end of each line instead of the whole string. s (dotAll) makes . also match newline characters.