RegEx Tester
Stop guessing and start testing. Our Regex Tester provides a visual sandbox for building and debugging complex regular expressions. With real-time highlighting and group matching, you can see exactly how your patterns interact with your sample data before you deploy them to production.
Essential for validating user input, text parsing, and string manipulation.
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How to Test Regex
- 1
Enter your regular expression pattern (e.g., /^[a-z]+$/).
- 2
Paste your test string into the textarea below.
- 3
Watch the real-time highlights to see which parts of your text match the pattern.
Regex Reference
Using Flags
Common flags include `i` (case-insensitive), `g` (global match - find all), and `m` (multiline).
Group Matching
Use parentheses `()` to create capture groups. Our tool will highlight each group separately so you can verify your data extraction logic.
Frequently Asked Questions
Which Regex flavor is used?
We use the standard JavaScript (ECMAScript) regex engine, which is consistent with what most web developers use.
Is it safe for large datasets?
Yes. Our high-performance matching happens locally in your browser, ensuring safety and speed even with thousands of lines of text.
Why Use This Tool?
- ✓Real-time match highlighting
- ✓Support for groups and capturing
- ✓Visual flag management
- ✓Instantly validates complex patterns