Question 1

How do I test a regular expression online?

Accepted Answer

Enter your regex pattern in the pattern field and paste your test string below. Matches are highlighted in real time as you type. Flags like global (g), case-insensitive (i), and multiline (m) can be toggled.

Question 2

What regex syntax does this tool support?

Accepted Answer

This tool uses JavaScript's native RegExp engine, supporting standard regex syntax including character classes, quantifiers, groups, lookahead, lookbehind, and named groups.

Question 3

How do I match an email address with regex?

Accepted Answer

A simple email regex is: [a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}. For production use, consider using a dedicated email validation library as RFC 5322-compliant email regex is extremely complex.

Regex Tester