How Regular Expression (Regex) Live Tester & Capture Group Inspector Works & When to Use It
Test JavaScript/ECMAScript Regular Expressions against sample text and inspect all matched strings, indices, and capture groups. Calculations and file processing run in this browser tab. The tool does not send working inputs or files to our hosting server.
Step-by-Step Instructions
- Enter the labelled values or choose an example.
- Run the tool and review the result and its assumptions.
- Copy or download the result. Reset restores defaults; Undo restores the previous settings.
Worked Examples
| Scenario | Input Parameters | Example Output |
|---|---|---|
| Match 6-Digit Indian PIN Codes (110001, 400001, 560001) | {"pattern": "\\b[1-9][0-9]{5}\\b", "flags": "g", "testText": "Deliveries to New Delhi 110001, Mumbai 400001, and Bengaluru ..."} |
110001, 400001, 560001 |
| Match Indian IFSC Codes (e.g. SBIN0001234, HDFC0000123) | {"pattern": "\\b[A-Z]{4}0[A-Z0-9]{6}\\b", "flags": "g", "testText": "Transfer to SBIN0001234 or HDFC0000123."} |
SBIN0001234, HDFC0000123 |
Formula, reference and effective date
- Reference Standard / Authority: ECMA-262 Regular Expression Grammar
- Applicable Period / Effective Date: 2025-2026
- Privacy & Execution Mode: Browser-Local Only (Zero Server Upload) (None (Pure Vanilla JS & Web Crypto))
Important Limitations & Edge Cases
Catches invalid regex syntax safely. Check the assumptions and output against your intended task before relying on the result.
Frequently Asked Questions (FAQs)
1. Is Regular Expression (Regex) Live Tester & Capture Group Inspector completely free to use without registration?
Yes. Every tool on Easy Tools Today is 100% free with no paywall, no sign-up, and no subscription required.
2. Are the numbers or files I enter uploaded to any server?
Calculations and file processing run in this browser tab. The tool does not send working inputs or files to our hosting server.
3. What should I check before using the result?
Check the assumptions and output against your intended task before relying on the result. Reference: ECMA-262 Regular Expression Grammar.