Regex Tester
Test regular expressions with live match highlighting and capture groups.
Runs in your browser · no upload
Regex tester
Test JavaScript regular expressions with live highlighting and capture groups.
g = all matches, i = ignore case, m = multiline, s = dot matches newline, u = unicode, y = sticky
Questions
Is my text uploaded?
No. Everything runs in your browser, so your text never leaves your device.
Which regex flavor is used?
JavaScript (ECMAScript) regular expressions, the same engine your browser and Node.js use, including named groups and lookbehind.
What happens with a very slow pattern?
Matching runs in a background worker and stops after 1.5 seconds, so a runaway pattern cannot freeze the page.