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Regex Tester

Test and debug regular expressions in real time

100% FreeRuns in your browserNo sign-up

About this tool

Build and test regular expressions with instant visual feedback. See matches highlighted in your test string as you type, inspect capture groups, and use replace mode to test substitutions. Quick-insert common patterns for emails, URLs, phone numbers, dates, and IP addresses.

Features

  • Real-time match highlighting
  • Flag toggles (g, i, m, s, u)
  • Capture group inspection
  • Find and replace mode
  • Common pattern quick-insert presets

Use cases

Debugging regular expressionsValidating input patternsBuilding search-and-replace rules

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Frequently Asked Questions

Is Regex Tester really free?

Yes, 100% free with no hidden fees. You can use it as many times as you want, directly in your browser.

Do I need to create an account?

No account is required. However, creating a free aukimi account removes watermarks and lets you save your work.

Is my data safe?

Yes. All processing happens locally in your browser. Your files are never uploaded to our servers.

Can I use the results for commercial projects?

Absolutely. Everything you create with our free tools is yours to use however you like, including for commercial purposes.