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YFT
Client-side ProcessingUpdated 2026-02-10Report issue

Runs fully in your browser. Inputs stay on your device. See recent fixes on changelog.

Regex Tester

Test regular expressions against a string in real time. See matches, capture groups, and match indices. Uses JavaScript regex flavor.

//g
Flags:
Match Results0 matches

Enter a pattern and test string to see matches

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About Regex Tester

Test regular expressions with live match highlighting, capture groups, and flag toggles. Test regular expressions online with live highlighting, capture groups, and flags. Free regex debugger. Everything runs client-side in your browser for maximum speed and privacy — no data is sent to any server, and no signup is required.

Related tools: JSON Formatter & Validator, Diff Checker, Base64 Encode / Decode

How to Use Regex Tester

  1. Enter your input into the tool.
  2. The tool processes it instantly in your browser.
  3. Copy the result to your clipboard.

Frequently Asked Questions

What is Regex Tester?
Test regular expressions online with live highlighting, capture groups, and flags. Free regex debugger.
Is Regex Tester free to use?
Yes, it is completely free to use. It runs entirely in your browser with no signup, no account, and no usage limits.
Is my data safe when using Regex Tester?
Yes. All processing happens locally in your browser. No data is uploaded to any server, so your information stays private and secure.