Regex Tester
Test regular expressions with flags, view matches, and highlight results—all in your browser.
Loading Tool…
Live Regex Tester & Debugger (JavaScript)
Master Regular Expressions with our real-time Regex Tester. Write and test JavaScript-compatible regex patterns against your sample text with instant match highlighting. We provide a detailed breakdown of capturing groups, match indices, and execution time, helping you debug complex patterns for form validation, data scraping, or string manipulation.
How it Works
- 1Enter your Regular Expression pattern (e.g., `^[\w-\.]+@([\w-]+\.)+[\w-]{2,4}$`).
- 2Paste your test string into the text area.
- 3Toggle flags like Global (g), Case Insensitive (i), or Multiline (m).
- 4See matches highlighted instantly in the text.
- 5View the 'Match Info' panel for detailed group capture data.
Key Features
Real-time highlighting of matches.
Support for standard JavaScript regex flags (g, i, m, s, u, y).
Explanation of match groups and indices.
Cheatsheet: Quick reference for common regex tokens.
Privacy: Patterns are tested locally in your browser.
Common Use Cases
Form Validation: Test email, password, or phone number patterns.Data Extraction: prototyping regex for web scrapers.Log Parsing: Build patterns to extract IDs or timestamps from server logs.Code Refactoring: Test search-and-replace patterns safely.
Frequently Asked Questions
Everything you need to know about using this tool effectively and securely.
Q.Which Regex engine does this use?
It uses your browser's native JavaScript RegExp engine. This ensures that the behavior matches exactly what you will see in your Node.js or frontend JavaScript code.
Related Tools
Related Tools
Enhance your workflow by combining these tools together