Regex Tester
Test JavaScript regular expressions locally for validation, parsing, and debugging workflows.
Local developer validation tool
Test regex patterns safely.
Enter a pattern and sample text to highlight matches, preview replacements, and inspect capture groups without sending data to a server.
When should you test regex?
Regex testing helps validate form input, parse logs, inspect API text, and debug extraction rules before using them in code.
This tool uses native JavaScript RegExp behavior and renders user text as text, not HTML.
Frequently Asked Questions
Is this Regex Tester free?
Yes. You can test patterns and preview replacements without signup.
Is my text uploaded?
No. Regex testing happens locally in your browser.
Which regex engine is used?
It uses the native JavaScript RegExp engine in your browser.
Are invalid regex patterns handled?
Yes. The tool shows a friendly warning and preserves your input.
Does it support Unicode regex?
Yes. Use the u flag for Unicode-aware patterns.
Privacy Policy
We do not collect, store, upload, or transmit regex patterns or test text entered into this tool.
Terms of Use
ConvertUnlimited is provided as is. Test expressions carefully before using them in production systems.