DevScratchpad

Regex Tester

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Test String
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177 characters • 3 lines Valid Pattern

Regex Tester & Matcher (Offline & Secure)

Test regular expressions in real-time with regex flag controls, group matches, and string replacement preview.

How to use

  1. Enter your regular expression pattern and flags.
  2. Paste test string into the text area.
  3. Inspect matched groups and highlighted ranges in real-time.

Important Considerations

  • Catastrophic backtracking prevention and lookbehinds.

Privacy Notice: This tool is strictly client-side. All processing runs in your local browser memory using JavaScript. No text, tokens, payloads, or logs are ever transmitted to any remote server or analytics engine. You can even use this tool completely offline.

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