Regex Tester

Test JavaScript regular expressions with live match highlighting, capture groups and replace preview.

Runs in your browser. Your data and files never leave your device.

About the Regex Tester

Write a pattern, choose flags and see every match highlighted in your test text, with capture groups and a replacement preview.

Pattern (\d{4})-(\d{2})-(\d{2}) on Due 2026-09-27 matches the date with three capture groups. Replace with $3/$2/$1 to get 27/09/2026.

Which regex flavour is this?

JavaScript (ECMAScript), as used in browsers and Node.js. Most syntax is shared with other languages.

What do the g, i and m flags do?

g finds every match instead of the first, i ignores case, and m makes ^ and $ match at the start and end of each line.