Regex Tester - Test Regular Expressions Online
Test, validate and learn regular expressions in real-time with visual highlighting, practical examples and complete reference guide.
Regex Tester
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g = global, i = ignore case, m = multiline, s = dotAll, u = unicode, y = sticky
What is a Regex Tester?
A regex tester is an online tool that lets you test and validate regular expressions in real-time. Enter your pattern, choose flags, input test text, and see matches immediately highlighted. Perfect for developers who want to debug, learn, or experiment with regular expressions in a visual and interactive way.
Key Features
- Real-time visual match highlighting
- Test with all JavaScript flags (g, i, m, s, u, y)
- 8 ready-to-use examples for Email, URLs, phones and more
- Complete reference guide with interactive accordion
- Details for each match: position, capture groups
- Clickable history of last 30 tests
- 100% client-side - maximum privacy
Common Use Cases
- Form validation (email, phone, SSN, etc)
- Debug regex patterns before implementing in code
- Learn and experiment with regex syntax
- Extract data from texts and logs
- Test edge cases and complex patterns
How to Use
Follow these simple steps to test your regular expressions:
- Enter your regex pattern in the 'Pattern' field (without the / / delimiters)
- Select desired flags by clicking the buttons (g, i, m, s, u, y)
- Enter the text you want to test in the 'Test String' field
- Press Enter or click 'Test' to see the results
- See highlighted matches and copy results if needed
Tips and Tricks
- Use the 'g' (global) flag to find all matches, not just the first one
- Explore the 'Examples' tab to see common patterns and learn from them
- Check the 'Cheat Sheet' when you forget any syntax
- Click on history items to quickly reload previous tests
- Always test your patterns with various examples, including edge cases