Regex Tester

Test regular expressions with real-time match highlighting

About This Tool

Test and debug regular expressions in real-time. Enter a regex pattern and sample text, and see instant match highlighting with detailed capture group results. All processing happens locally in your browser — your data never leaves your device.

How to Use

  1. Enter your regex pattern in the Pattern field.
  2. Select flags (g for global, i for case-insensitive, etc.).
  3. Paste your test text in the Sample Text area.
  4. Click Test to see highlighted matches and capture groups.

Why Choose OmniTools?

⚡ Instant Results

Zero server lag. All calculations run locally on your device for maximum speed.

🛡️ 100% Private

Your data never leaves your device. No uploads, no servers, no tracking.

Frequently Asked Questions

What regex engine is used?

This tool uses JavaScript's native RegExp engine, which supports most standard regex features.

What does the 'g' flag do?

The global (g) flag finds all matches in the text, not just the first one. Without it, only the first match is returned.

What does the 'i' flag do?

The case-insensitive (i) flag makes the pattern match both uppercase and lowercase letters.

What is a capture group?

Capture groups are defined with parentheses () and let you extract specific parts of a match for further processing.

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