ONTOOLS

Regex Tester

Test regex matches and replacement output.

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Test regular expressions against sample text and preview matches and replacements. This is useful for validation, search/replace workflows, and parsing logs or content. Use it to iterate quickly before applying regex in code or editors.

How to use

  1. Enter your regex pattern.

  2. Paste test text.

  3. Review matches and groups.

  4. Try replacement mode if available.

FAQ

  • What regex flavor is used? Usually JavaScript-style regex in the browser.

  • Do flags work (g, i, m)? Typically yes if supported by UI.

  • Can I test replacements? Yes in replace mode.

  • Why does it fail? Pattern may be invalid or unsupported feature.