NexoraStack Tools
Regex Tester
Test regular expressions against text, try common flags, and inspect match results in your browser. Useful for validation, parsing, and debugging patterns.
Tool Interface
Result lines: 0
Functional explanation
This regex tester helps you run regular expressions against sample text and inspect matches, groups, and flag behavior in one place. It is useful for quick debugging before you embed a pattern into app code or a validation rule.
- Test validation patterns before adding them to forms or APIs.
- Check search-and-replace logic against real sample text.
- Inspect how flags change matching behavior in JavaScript-style regex workflows.
How to use
Use this regex tester to check patterns, flags, and match output before you move them into production code, search rules, or validation logic.
- Enter a regex pattern.
- Add flags such as g, i, or m if needed.
- Paste sample text to test against.
- Review matches and refine the pattern.
Example
Input
Pattern: ^[a-z0-9._%+-]+@[a-z0-9.-]+\.[a-z]{2,}$
Text: [email protected]Output
Match found: [email protected]
Useful for trying validation patterns before moving them into application code.
Common mistakes
- Forgetting to escape special characters like . or ? when you want them treated literally.
- Using the wrong flag set and assuming the pattern itself is broken.
Output interpretation tips
- A pattern may work differently depending on flags such as g, i, or m.
- If nothing matches, test against a smaller sample string first to isolate the issue.
Security and privacy notes
- Regex testing runs locally in the browser.
- Avoid pasting sensitive production text into any shared environment while debugging patterns.
FAQ
Does this support regex flags?
Yes, common flags like g, i, m, s, u, and y are supported.
Is the input text sent to a server?
No. Pattern testing happens locally in your browser.
What is this tool best for?
It is best for debugging validation patterns, text-matching rules, parsing logic, and quick regex experiments.