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Regex Tester

Try a JavaScript regular expression against sample text, inspect capture groups, and preview a replacement. The pattern is compiled with the RegExp engine in your browser.

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This runs entirely in your browser. Nothing you type is sent to a server.

How to test a regular expression

  1. 1Enter a pattern without surrounding slashes, then choose flags.
  2. 2Paste the text you want to test. Matches and capture groups are listed underneath.
  3. 3Add a replacement if you want to preview the result. Use $1, $2 and so on for groups.

Questions

Which regex flavour is this?

JavaScript. Lookbehind and named groups work in current browsers. A pattern copied from another language may need small changes.

What does the global flag change?

With g, every non-overlapping match is listed. Without it, only the first match is shown, which is how RegExp behaves in JavaScript.

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