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regex-tester

Regex Tester

Test regular expression patterns and flags directly in your browser. Check matches and capture groups instantly. Free online tool with no signup required. Works directly in your browser and is designed for quick same-page results.

g: all matches, i: ignore case, m: multiline, s: dot matches newline, u: Unicode, y: sticky.

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Test patterns, flags, and capture groups before you use a regex in code or data cleanup

Use Regex Tester when you are building a regular expression for validation, search, parsing, log cleanup, or text extraction and want to see matches immediately.

Why this developer tool is useful

  • Try a pattern against sample text and see matches update quickly.
  • Check capture groups and flags before copying the regex into code, configs, or data tools.
  • Useful for form validation, cleanup scripts, parsing rules, and debugging pattern mistakes.

How to use Regex Tester

  1. Paste the text or data you want to process.
  2. Adjust the settings and check the preview or result.
  3. Run the tool and review the final result.

Regex Tester FAQ

Is Regex Tester free to use?

Yes. You can use Regex Tester on this page without signup.

Can I use Regex Tester in the browser?

Yes. This page is built for quick browser-based use on the same page.

What is Regex Tester useful for?

Test regular expression patterns and flags directly in your browser. Check matches and capture groups instantly.