CalcCafe

Regex Tester

Write a regular expression and watch it match your test text live, with every hit highlighted. JavaScript flavour, in your browser.

matches

How it works

Your pattern and flags build a native RegExp, which is run against your test string with matchAll; each match is highlighted in place — all in your browser.

100% client-side — nothing you paste is ever uploaded.

Frequently asked questions

Which regex flavour is this?
JavaScript (ECMAScript) regular expressions — the same engine your browser and Node.js use. Add flags like g, i and m.
Does it highlight matches?
Yes — every match is highlighted directly in your test string as you type, and the match count updates live.

Related tools