Regex Tester
Write a regular expression and watch it match your test text live, with every hit highlighted. JavaScript flavour, in your browser.
Reviewed by the CalcCafe editorial team · Last updated 1 July 2026 · How we test our tools
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
Sources & references
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