Clacify

Regex Tester

Test regular expressions with live match highlighting

Built & maintained by Pappu Venkata Subbi Reddy, founder of Clacify

About Regex Tester

Clacify's Regex Tester lets you write and test regular expressions with live match highlighting as you type. Supports full JavaScript regex syntax including groups, lookaheads, and all standard flags (g for global, i for case-insensitive, m for multiline). The tool shows all matches highlighted in the test string, along with captured groups and match positions — essential for validating email patterns, parsing log files, form validation, and data extraction.

Frequently Asked Questions

How to test a regex pattern online?

Enter your regex pattern (without slashes) in the Pattern field, add any flags (g, i, m), paste your test string, and matches are highlighted live. Clacify's Regex Tester uses JavaScript's native RegExp engine — the same engine used in Node.js, Chrome, and all modern browsers.

What are common regex patterns?

Email: ^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$. Phone (India 10-digit): ^[6-9]\d{9}$. PIN code (India): ^[1-9][0-9]{5}$. URL: https?:\/\/(www\.)?[-a-zA-Z0-9@:%._+~#=]{1,256}\.[a-zA-Z0-9()]{1,6}. IP address: \b(?:\d{1,3}\.){3}\d{1,3}\b.

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