What regex flags are available?

Common JavaScript regex flags include: g (global — find all matches), i (case-insensitive), m (multiline — ^ and $ match line boundaries), s (dotAll — dot matches newlines), and u (unicode). You can combine flags, e.g. /pattern/gi.

Is my data sent to a server?

No. This regex tester runs entirely in your browser using JavaScript. Your patterns and test strings are never transmitted to any server, making it safe for testing patterns with sensitive data.

Regex Tester

Enter a regular expression pattern and test string below. Matches are highlighted live as you type.

Pattern

/ /

Test String

Frequently Asked Questions

What is a regular expression?

A regular expression (regex) is a sequence of characters that defines a search pattern. It is used in programming to find, match, and manipulate strings — from input validation to data extraction.

What flags are available?

Common flags: g (global), i (case-insensitive), m (multiline), s (dotAll), u (unicode). Combine them as needed, e.g. gi.

Is my data private?

Yes. This regex tester runs entirely in your browser. Your patterns and test strings are never sent to any server, making it safe for sensitive data.