About Regex Tester
Test and debug regular expressions online with real-time matching, syntax highlighting, and built-in cheat sheet. Perfect for developers learning regex or debugging patterns.
Key Features
- ⚡ Real-Time Testing: See matches instantly as you type
- 🎨 Syntax Highlighting: Color-coded regex patterns and matches
- 📋 Match Details: View all matches with groups and positions
- 🔧 Regex Flags: Support for global, case-insensitive, and multiline flags
- 📚 Built-in Cheat Sheet: Quick reference for regex patterns
- 📱 Mobile Optimized: Works perfectly on all devices
- 🔒 100% Private: All processing happens in your browser
Common Regex Patterns
📧 Email & Web
- Email pattern for validation
- URL pattern for links
- Domain name matching
- IP address validation
📞 Phone & Numbers
- Phone number formats
- Currency amounts
- Decimal numbers
- Integer validation
Regex Flags
- 🌐 Global (g): Find all matches, not just the first one
- 🔤 Case Insensitive (i): Ignore case when matching
- 📄 Multiline (m): ^ and $ match line breaks
- 🔍 Dotall (s): . matches newline characters
Frequently Asked Questions
What is the Regex Tester tool used for?
Our Regex Tester helps you write, test, and debug regular expressions (regex). You can type a pattern and see exactly which parts of your test text it matches in real-time.
Does this tool support global matching and case insensitivity?
Yes, you can toggle flags like Global (g), Case-Insensitive (i), and Multiline (m) to modify how your regular expression behaves.
Is there a regex cheat sheet included?
Yes, the tool includes a built-in cheat sheet that covers common regex patterns like character classes, quantifiers, and anchors to help you build patterns faster.
Is my data private while I test my patterns?
Absolutely. All regex processing happens locally in your browser. We do not store or transmit your test text or regex patterns to any server.
Which regex engine does this tool use?
This tool uses the standard JavaScript RegExp engine, which is consistent with the regex behavior found in most modern web browsers and Node.js.
How to Use
- Enter your regular expression pattern in the regex field
- Add your test text in the input area
- Select appropriate flags (global, case-insensitive, multiline)
- View real-time matches with highlighting
- Check match details including groups and positions
- Use the cheat sheet for pattern reference