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Regex Tester

Write a regular expression and see every match highlighted in your test text, with capture groups.

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How to use

  1. Type a regular expression and toggle the flags you need (g, i, m, s, u, y).
  2. Paste text into the test string box.
  3. See matches highlighted live, with a table of capture groups and positions.
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Frequently asked questions

Which regex flavor is this?

JavaScript (ECMAScript) regular expressions, using your browser's built-in RegExp engine.

What do the flags mean?

g = global (all matches), i = ignore case, m = multiline, s = dotall (dot matches newlines), u = unicode, y = sticky.

Is my text sent anywhere?

No. The pattern runs against your text entirely in the browser — nothing is uploaded.

About this tool

Regex Tester is a free, browser-based tool from Tools Platform. It runs entirely on your device — your data is never uploaded to a server, so it stays completely private. There are no accounts, no watermarks, and no limits. Write a regular expression and see every match highlighted in your test text, with capture groups.