Introduction

Regex Tester Online is a free tool that lets you test regular expressions against any text in real time. See matches highlighted, captured groups listed, and toggle regex flags easily.

How to use:

1. Enter your regular expression in the "Regex" field.

2. Toggle flags (global, case-insensitive, multiline, dotall) as needed.

3. Enter your test string in the "Test String" field.

4. Results update in real time: matches are highlighted and groups are shown below.

Regular Expression:

Test String:

Match Result:

Captured Groups:

About Regex Tester Online:

Regular expressions (regex) are powerful patterns used for matching, searching, and replacing text. They are used in virtually every programming language, text editors, and command-line tools.

This tool uses JavaScript's built-in RegExp engine. All processing happens entirely in your browser. No data is sent to any server. Supported flags include global (g), case-insensitive (i), multiline (m), and dotall (s).